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Lee SS, Nagar S, Rajagopalan L, Orilla W, Csaky KG, Almazan A, Yang L, Robinson MR. Using a Novel, Subconjunctival, Sustained-Release Mitomycin C Formulation in a Rabbit Model of Filtration Surgery with Gel Stent Implantation. J Ocul Pharmacol Ther 2024. [PMID: 38687355 DOI: 10.1089/jop.2023.0100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024] Open
Abstract
Purpose: To investigate gel stent implantation with and without intraoperative sustained-release mitomycin C (MMC SR) in a rabbit model for gel stent implantation, and to examine aqueous humor outflow (AHO) postimplantation. Methods: Four groups of rabbits were included. Group 1 was untreated (control). Groups 2, 3, and 4 received the gel stent without MMC, with MMC solution (subconjunctival injection), and with MMC SR (subconjunctival injection), respectively. Intraocular pressure (IOP) and AHO were assessed via tonometry and indocyanine green-based angiography, respectively. The main efficacy measure was change in IOP from baseline. Results: Following gel stent implantation, Groups 2, 3, and 4 maintained ≥20% IOP reduction (response) for a median duration of 1 week, 6.5 weeks, and 30 weeks, respectively. Angiography showed normal aqueous humor drainage (Group 1) beginning at the perilimbal trabecular plexus and continuing posteriorly to episcleral outflow vessels. Following implantation, drainage occurred preferentially and directly into the subconjunctival bleb. Conclusions: Gel stent implantation with MMC SR was most effective in achieving sustained, long-term IOP reduction in the rabbit model, compared with implantation with or without MMC solution. Bleb presence and the postimplantation aqueous angiography results indicated redirection of the AHO to the subconjunctival vasculature and presumed lymphatics, suggesting efficient glaucoma filtration to lower IOP in this model. This rabbit model and aqueous angiography may help refine understanding of the mechanism of action of minimally invasive glaucoma surgeries and ultimately translate to improved surgical devices and procedures for patients with glaucoma.
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Affiliation(s)
- Susan S Lee
- Allergan, an AbbVie company, Irvine, California, USA
| | - Saumya Nagar
- Allergan, an AbbVie company, Irvine, California, USA
| | | | | | - Karl G Csaky
- Retina Foundation of the Southwest, Dallas, Texas, USA
| | | | - Liuqing Yang
- Allergan, an AbbVie company, Irvine, California, USA
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Strohmaier CA, Wanderer D, Zhang X, Zhang HF, Strohmaier S, Weinreb RN, Huang AS. Lack of Correlation Between Segmental Trabecular Meshwork Pigmentation and Angiographically Determined Outflow in Ex Vivo Human Eyes. J Glaucoma 2024; 33:355-360. [PMID: 37851964 PMCID: PMC10995104 DOI: 10.1097/ijg.0000000000002318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 09/18/2023] [Indexed: 10/20/2023]
Abstract
PRCIS Trabecular meshwork (TM) pigmentation is not correlated with angiographically determined aqueous humor outflow (AHO) in an ex vivo perfusion model using human eyes. PURPOSE To evaluate whether segmental TM pigmentation is correlated to segmental AHO in human eyes. METHODS Postmortem human eyes were acquired, and anterior segments were dissected. TM pigmentation was photographed 360-degrees around the eye. The anterior segments were then mounted onto a perfusion apparatus and perfused with Dulbecco's phosphate buffered saline (DPBS) until a stabile baseline outflow facility was achieved. Aqueous angiography (AHO angiography) was performed using fluorescein (2%), and segmental AHO was documented around the limbus using an angiographic camera (Spectralis HRA+OCT). Circumferential and nasal TM pigmentation were compared with respective angiographic outflow imaging using a Pearson correlation analysis. RESULTS Segmental TM pigment distribution and segmental AHO were seen. TM pigment was statistically greatest in the inferior quadrant. AHO angiographic outflow was numerically greatest in the nasal quadrant, but this was not statistically significant. No statistically significant correlation was observed (r=-0.083, P =0.06) between segmental TM pigmentation and segmental AHO angiographic signal. Analyzing just the nasal quadrant, a significant weak negative correlation was found (r=-0.296, P =0.001). DISCUSSION Segmental TM pigmentation circumferentially around the eye is not a good proxy for segmental AHO circumferentially around the eye and should not be used to guide trabecular minimally invasive glaucoma surgeries.
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Affiliation(s)
- Clemens A. Strohmaier
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, CA, USA
- Department of Ophthalmology and Optometry, Kepler University Hospital, Johannes Kepler University, Linz, Austria
| | - Daniel Wanderer
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, CA, USA
| | - Xiaowei Zhang
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, CA, USA
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Susanne Strohmaier
- Department of Epidemiology, Center for Public Health, Medical University of Vienna, Vienna, Austria
| | - Robert N. Weinreb
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, CA, USA
| | - Alex S. Huang
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, CA, USA
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Gupta S, Zhang X, Panigrahi A, Shakha, Fang R, Strohmaier CA, Zhang HF, Weinreb RN, Gupta V, Huang AS. Reduced Aqueous Humor Outflow Pathway Arborization in Childhood Glaucoma Eyes. Transl Vis Sci Technol 2024; 13:23. [PMID: 38536170 PMCID: PMC10981159 DOI: 10.1167/tvst.13.3.23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 02/16/2024] [Indexed: 04/01/2024] Open
Abstract
Purpose To compare aqueous humor outflow (AHO) pathway patterns between eyes of childhood glaucoma patients and non-glaucomatous patients receiving cataract surgery. Methods Aqueous angiography was performed in childhood glaucoma eyes (n = 5) receiving glaucoma surgery and in pediatric (n = 1) and healthy adult (n = 5) eyes receiving cataract surgery. Indocyanine green (0.4%) was introduced into the anterior chamber, and AHO was imaged using an angiographic camera (SPECTRALIS HRA+OCT with Flex Module). Images were acquired and analyzed (ImageJ with Analyze Skeleton 2D/3D plugin) from the nasal sides of the eyes, the usual site of glaucoma angle procedures. Image analysis endpoints included AHO vessel length, maximum vessel length, number of branches, number of branch junctions, and vessel density. Results Qualitatively, childhood glaucoma eyes demonstrated lesser AHO pathway arborization compared to pediatric and adult eyes without glaucoma. Quantitatively, childhood glaucoma and healthy adult cataract eyes showed similar AHO pathway average branch lengths and maximum branch lengths (P = 0.49-0.99). However, childhood glaucoma eyes demonstrated fewer branches (childhood glaucoma, 198.2 ± 35.3; adult cataract, 506 ± 59.5; P = 0.002), fewer branch junctions (childhood glaucoma, 74.6 ± 13.9; adult cataract, 202 ± 41.2; P = 0.019), and lower vessel densities (childhood glaucoma, 8% ± 1.4%; adult cataract, 17% ± 2.5%; P = 0.01). Conclusions Childhood glaucoma patients demonstrated fewer distal AHO pathways and lesser AHO pathway arborization. These anatomical alternations may result in a new source of trabecular meshwork-independent AHO resistance in this disease cohort. Translational Relevance Elevated distal outflow pathway resistance due to decreased AHO pathway arborization may explain some cases of failed trabecular bypass surgery in childhood glaucoma.
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Affiliation(s)
- Shikha Gupta
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute for Medical Sciences, New Delhi, India
| | - Xiaowei Zhang
- Hamilton Glaucoma Center, Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, San Diego, CA, USA
| | - Arnav Panigrahi
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute for Medical Sciences, New Delhi, India
| | - Shakha
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute for Medical Sciences, New Delhi, India
| | - Raymond Fang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Clemens A. Strohmaier
- Hamilton Glaucoma Center, Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, San Diego, CA, USA
- Department of Ophthalmology and Optometry, Kepler University Hospital, Johannes Kepler University, Linz, Austriav
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Robert N. Weinreb
- Hamilton Glaucoma Center, Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, San Diego, CA, USA
| | - Viney Gupta
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute for Medical Sciences, New Delhi, India
| | - Alex S. Huang
- Hamilton Glaucoma Center, Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, San Diego, CA, USA
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Strohmaier CA, Wanderer D, Zhang X, Agarwal D, Toomey CB, Wahlin K, Zhang HF, Stamer WD, Weinreb RN, McDonnell FS, Huang AS. Greater Outflow Facility Increase After Targeted Trabecular Bypass in Angiographically Determined Low-low Regions. Ophthalmol Glaucoma 2023; 6:570-579. [PMID: 37348815 PMCID: PMC10917462 DOI: 10.1016/j.ogla.2023.06.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/31/2023] [Accepted: 06/14/2023] [Indexed: 06/24/2023]
Abstract
PURPOSE To investigate the impact of trabecular bypass surgery targeted to angiographically determined high- vs. low-aqueous humor outflow areas on outflow facility (C) and intraocular pressure (IOP). DESIGN Ex vivo comparative study. SUBJECTS Postmortem ex vivo porcine and human eyes. METHODS Porcine (n = 14) and human (n = 13) whole globes were acquired. In both species, anterior segments were dissected, mounted onto a perfusion chamber, and perfused using Dulbecco's phosphate buffered solution containing glucose in a constant flow paradigm to achieve a stable baseline. Fluorescein was perfused into the anterior chamber and used to identify baseline segmental high- and low-flow regions of the conventional outflow pathways. The anterior segments were divided into 2 groups, and a 5 mm needle goniotomy was performed in either a high- or low-flow area. Subsequently, C and IOP were quantitatively reassessed and compared between surgery in baseline "high-flow" and "low-flow" region eyes followed by indocyanine green angiography. MAIN OUTCOME MEASURES Outflow facility. RESULTS In all eyes, high- and low-flow segments could be identified. Performing a 5-mm goniotomy increased outflow facility to a variable extent depending on baseline flow status. In the porcine high-flow group, C increased from 0.31 ± 0.09 to 0.39 ± 0.09 μL/mmHg/min (P = 0.12). In the porcine low-flow group, C increased from 0.29 ± 0.03 to 0.56 ± 0.10 μL/mmHg/min (P < 0.001). In the human high-flow group, C increased from 0.38 ± 0.20 to 0.41 ± 0.20 μL/mmHg/min (P = 0.02). In the human low-flow group, C increased from 0.25 ± 0.11 to 0.32 ± 0.11 μL/mmHg/min (<0.001). There was statistically significant greater increase in C for eyes where surgery was targeted to baseline low-flow regions in both porcine (0.07 ± 0.09 vs. 0.27 ± 0.13, P = 0.007 μL/mmHg/min, high vs low flow) and human eyes (0.03 ± 0.03 vs. 0.07 ± 0.02, P = 0.03 μL/mmHg/min, high vs. low flow). CONCLUSIONS Targeting surgery to low-flow areas of the trabecular meshwork yields higher overall facility increase and IOP reduction compared to surgery in high-flow areas. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
- Clemens A Strohmaier
- Department of Ophthalmology and Optometry, Kepler University Hospital, Johannes Kepler University, Linz, Austria; The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California.
| | - Daniel Wanderer
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
| | - Xiaowei Zhang
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
| | - Devansh Agarwal
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
| | - Christopher B Toomey
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
| | - Karl Wahlin
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
| | - Hao F Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
| | - W Daniel Stamer
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
| | - Robert N Weinreb
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
| | | | - Alex S Huang
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
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Johnstone M, Xin C, Martin E, Wang R. Trabecular Meshwork Movement Controls Distal Valves and Chambers: New Glaucoma Medical and Surgical Targets. J Clin Med 2023; 12:6599. [PMID: 37892736 PMCID: PMC10607137 DOI: 10.3390/jcm12206599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/09/2023] [Accepted: 08/30/2023] [Indexed: 10/29/2023] Open
Abstract
Herein, we provide evidence that human regulation of aqueous outflow is by a pump-conduit system similar to that of the lymphatics. Direct observation documents pulsatile aqueous flow into Schlemm's canal and from the canal into collector channels, intrascleral channels, aqueous veins, and episcleral veins. Pulsatile flow in vessels requires a driving force, a chamber with mobile walls and valves. We demonstrate that the trabecular meshwork acts as a deformable, mobile wall of a chamber: Schlemm's canal. A tight linkage between the driving force of intraocular pressure and meshwork deformation causes tissue responses in milliseconds. The link provides a sensory-motor baroreceptor-like function, providing maintenance of a homeostatic setpoint. The ocular pulse causes meshwork motion oscillations around the setpoint. We document valves entering and exiting the canal using real-time direct observation with a microscope and multiple additional modalities. Our laboratory-based high-resolution SD-OCT platform quantifies valve lumen opening and closing within milliseconds synchronously with meshwork motion; meshwork tissue stiffens, and movement slows in glaucoma tissue. Our novel PhS-OCT system measures nanometer-level motion synchronous with the ocular pulse in human subjects. Movement decreases in glaucoma patients. Our model is robust because it anchors laboratory studies to direct observation of physical reality in humans with glaucoma.
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Affiliation(s)
- Murray Johnstone
- Department of Ophthalmology, University of Washington, Seattle, WA 98195, USA;
| | - Chen Xin
- Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing 100730, China
- Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Elizabeth Martin
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
| | - Ruikang Wang
- Department of Ophthalmology, University of Washington, Seattle, WA 98195, USA;
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
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Gołaszewska K, Obuchowska I, Konopińska J. First-Generation iStent Bypass Implantation versus ab Externo Canaloplasty Combined with Phacoemulsification in Patients with Primary Open Angle Glaucoma-12-Month Follow-Up. J Clin Med 2023; 12:5711. [PMID: 37685778 PMCID: PMC10488869 DOI: 10.3390/jcm12175711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/29/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023] Open
Abstract
This prospective, non-randomized, interventional clinical study evaluated the efficacy and safety profile of first-generation iStent bypass implantation versus ab externo canaloplasty, both combined with phacoemulsification, in patients with primary open-angle glaucoma (POAG) after 12-month follow-up. A total of 138 patients with POAG and their 138 eyes (69 phaco-iStent and 69 phacocanaloplasty) were included. Postoperatively at 12 months, the mean intraocular pressure (IOP) decreased from 18.44 ± 3.88 to 15.51 ± 2.50 mmHg and from 17.20 ± 4.04 to 14.97 ± 2.37 mmHg in the phaco-iStent (PiS) and phacocanaloplasty (PC) groups, respectively (p = 0.480). In both groups, 35.7% achieved >20% IOP reduction from baseline. A total of 86% and 71.4% of the eyes were medication-free at 12 months in the PiS and PC groups, respectively. In both groups, all eyes showed improvement in best-corrected visual acuity compared with baseline and demonstrated similar safety profiles throughout the 12-month follow-up period. This study showed equal hypotensive effects of PiS and PC. Both procedures significantly reduced the IOP and the requirement for IOP-lowering medications for at least 12 months postoperatively, with no significant differences between the groups.
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Affiliation(s)
| | | | - Joanna Konopińska
- Department of Ophthalmology, Medical University of Białystok, 15-089 Białystok, Poland; (K.G.); (I.O.)
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Strohmaier CA, McDonnell FS, Zhang X, Wanderer D, Stamer WD, Weinreb RN, Huang AS. Differences in Outflow Facility Between Angiographically Identified High- Versus Low-Flow Regions of the Conventional Outflow Pathways in Porcine Eyes. Invest Ophthalmol Vis Sci 2023; 64:29. [PMID: 36939719 PMCID: PMC10043501 DOI: 10.1167/iovs.64.3.29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023] Open
Abstract
Purpose To investigate differences in outflow facility between angiographically determined high- and low-flow segments of the conventional outflow pathway in porcine eyes. Methods Porcine anterior segments (n = 14) were mounted in a perfusion chamber and perfused using Dulbecco's phosphate buffered solution with glucose. Fluorescein angiography was performed to determine high- and low-flow regions of the conventional outflow pathways. The trabecular meshwork (TM) was occluded using cyanoacrylate glue, except for residual 5-mm TM areas that were either high or low flow at baseline, designating these eyes as "residual high-flow" or "residual low-flow" eyes. Subsequently, outflow was quantitatively reassessed and compared between residual high-flow and residual low-flow eyes followed by indocyanine green angiography. Results Fluorescein aqueous angiography demonstrated high-flow and low-flow regions. Baseline outflow facilities were 0.320 ± 0.08 and 0.328 ± 0.10 µL/min/mmHg (P = 0.676) in residual high-flow and residual low-flow eyes before TM occlusion, respectively. After partial trabecular meshwork occlusion, outflow facility decreased to 0.209 ± 0.07 µL/min/mmHg (-32.66% ± 19.53%) and 0.114 ± 0.08 µL/min/mmHg (-66.57% ± 23.08%) in residual high- and low-flow eyes (P = 0.035), respectively. There was a significant difference in the resulting IOP increase (P = 0.034). Conclusions Angiographically determined high- and low-flow regions in the conventional outflow pathways differ in their segmental outflow facility; thus, there is an uneven distribution of local outflow facility across different parts of the TM.
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Affiliation(s)
- Clemens A Strohmaier
- Department of Ophthalmology and Optometry, Kepler University Hospital, Johannes Kepler University, Linz, Austria
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States
| | - Fiona S McDonnell
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Xiaowei Zhang
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States
| | - Daniel Wanderer
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States
| | - W Daniel Stamer
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States
| | - Robert N Weinreb
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States
| | - Alex S Huang
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States
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Dada T, Bukke AN, Huang AS, Sharma N, Verma S. Recruitment of Temporal Aqueous Outflow Channels After Bent Needle Ab-Interno Goniectomy Demonstrated by Aqueous Angiography. J Glaucoma 2023; 32:e15-e18. [PMID: 36223300 PMCID: PMC9877127 DOI: 10.1097/ijg.0000000000002131] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 09/20/2022] [Indexed: 11/07/2022]
Abstract
PURPOSE To demonstrate the utility of operating on the temporal trabecular meshwork with in vivo - aqueous angiography demonstrating new aqueous outflow channels. METHOD In a patient with primary open angle glaucoma, nuclear sclerosis, and medically uncontrolled intraocular pressure, Indocyanine green aqueous angiography (0.5%) was performed to visualize baseline functional aqueous outflow channels. This was followed by 30 degrees bent needle ab-interno goniectomy in the temporal quadrant, where no aqueous outflow channels were initially visualized. Aqueous angiography was repeated using 2% fluorescein to visualize aqueous outflow channels after bent needle ab-interno goniectomy. RESULTS Prebent needle ab-interno goniectomy, aqueous angiography revealed functional outflow channels in the nasal quadrant although none were visible in the temporal quadrant. Postbent needle ab-interno goniectomy in temporal quadrant aqueous angiography demonstrated 2 new aqueous outflow channels. CONCLUSION In a patient with open angle glaucoma, following temporal quadrant ab-interno goniectomy, the recruitment of aqueous outflow channels was demonstrated using aqueous angiography.
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Affiliation(s)
- Tanuj Dada
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS,
New Delhi, India
| | - Anand Naik Bukke
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS,
New Delhi, India
| | - Alex S Huang
- Hamilton Glaucoma Center, The Viterbi Family Department of
Ophthalmology, Shiley Eye Institute, University of California, San Diego, CA,
USA
| | - Namrata Sharma
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS,
New Delhi, India
| | - Saurabh Verma
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS,
New Delhi, India
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Lee JY, Wu J, Liu Y, Saraswathy S, Zhou L, Bu Q, Su Y, Choi D, Park E, Strohmaier CA, Weinreb RN, Hong YK, Pan X, Huang AS. Subconjunctival Lymphatics Respond to VEGFC and Anti-Metabolites in Rabbit and Mouse Eyes. Invest Ophthalmol Vis Sci 2022; 63:16. [PMID: 36166215 PMCID: PMC9526361 DOI: 10.1167/iovs.63.10.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To characterize and pharmacologically influence subconjunctival lymphatics in rabbit and mouse eyes. Methods Rabbits received subconjunctival injections of trypan blue or fixable fluorescent dextrans. Bleb-related outflow pathways were quantified. Immunofluorescence for vessel-specific markers (lymphatics [podoplanin and LYVE-1] and blood vessels [CD31]) were performed in native rabbit conjunctiva and after fixable fluorescent dextran injection. Vascular endothelial cell growth factor-C (VEGFC) was injected subconjunctivally in rabbits. mRNA and protein were assessed for the above markers using RT-PCR and Western blot. Alternatively, mouse studies used Prox1-tdTomato transgenic reporter mice. Subconjunctival injection conditions included: no injection, balanced salt solution (BSS), VEGFC, 5-fluorouracil (5FU) and two concentrations of mitomycin-C (MMC). Two mouse injection protocols (short and long) with different follow-up times and number of injections were performed. Mouse eyes were enucleated, flat mounts created, and subconjunctival branching and length assessed. Results Rabbit eyes demonstrated clear bleb-related subconjunctival outflow pathways that were distinct from blood vessels and were without nasal/temporal predilection. Immunofluorescence against vessel-specific markers showed lymphatics and blood vessels in rabbit conjunctiva, and these lymphatics overlapped with bleb-related subconjunctival outflow pathways. Subconjunctival VEGFC increased lymphatic (P = 0.004-0.04) but not blood vessel (P = 0.77-0.84) mRNA or protein in rabbits. Prox1-tdTomato transgenic reporter mice demonstrated natively fluorescent lymphatics. Subconjunctival VEGFC increased murine lymphatic branching and length (P ≤ 0.001-0.004) while antimetabolites (P ≤ 0.001-0.043) did the opposite for the long protocol. Discussion Subconjunctival lymphatics are pharmacologically responsive to both VEGFC and antimetabolites in two animal models studied using different methodologies. These results may be important for bleb-forming glaucoma surgeries or ocular drug delivery.
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Affiliation(s)
- Jong Yeon Lee
- Department of Ophthalmology, Gachon University College of Medicine, Gil Medical Center, Incheon, Korea
| | - Jingyi Wu
- Weifang Medical University, Weifang, Shandong Province, China.,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, Shandong Province, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, Shandong Province, China
| | - Yameng Liu
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, Shandong Province, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, Shandong Province, China
| | - Sindhu Saraswathy
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, United States
| | - Longfang Zhou
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, Shandong Province, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, Shandong Province, China
| | - Qianwen Bu
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, Shandong Province, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, Shandong Province, China
| | - Ying Su
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, Shandong Province, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, Shandong Province, China
| | - Dongwon Choi
- Department of Surgery, Norris Comprehensive Cancer Center Keck School of Medicine, University of Southern California, Los Angeles, California, United States
| | - Eunkyung Park
- Department of Surgery, Norris Comprehensive Cancer Center Keck School of Medicine, University of Southern California, Los Angeles, California, United States
| | - Clemens A Strohmaier
- Department of Ophthalmology, Johannes Kepler University, Linz, Austria.,Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States
| | - Robert N Weinreb
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States
| | - Young-Kwon Hong
- Department of Surgery, Norris Comprehensive Cancer Center Keck School of Medicine, University of Southern California, Los Angeles, California, United States
| | - Xiaojing Pan
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, Shandong Province, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, Shandong Province, China
| | - Alex S Huang
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States
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Tokuda N, Kitaoka Y, Tsukamoto A, Toyoda Y, Yamada Y, Sase K, Takagi H. Comparison of minimally invasive glaucoma surgery with trabecular micro-bypass stent and microhook ab interno trabeculotomy performed in conjunction with cataract surgery. Int J Ophthalmol 2022; 15:1082-1088. [PMID: 35919323 DOI: 10.18240/ijo.2022.07.07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 01/26/2022] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the effectuality and safety of cataract surgery combined with either ab interno trabeculotomy by the microhook (µLOT) or a single iStent® trabecular bypass implantation (iStent) in eyes with cataract and mild-to-moderate glaucoma. METHODS This study enrolled subjects with mild-to-moderate open angle glaucoma with visually significant cataract who used two or more ophthalmic antiglaucoma agents between 60 and 90y of age. Patients underwent cataract surgery cooperated with either implantation of an iStent (iStent-phaco) or excisional goniotomy with the µLOT (µLOT-phaco). Patients underwent µLOT-phaco in the eye with lower the mean deviation, according to the Humphrey field analyzer, while iStent-phaco was carried out on the other eye. Intraocular pressure (IOP) pre- and post-surgery, alterations in anterior chamber flare (ACF), and corneal endothelial cell density (ECD) were estimated. RESULTS Twenty subjects were enrolled (mean age: 73.6±7.3y). The mean medicated preoperative IOP was 16.7 mm Hg in the µLOT and 16.2 mm Hg in the iStent eyes. The mean final IOP at 12mo was 13.6 mm Hg in the µLOT eyes and 13.6 mm Hg in the iStent eyes, representing a 17.8% and 17.2% reduction, respectively. The preoperative ACF in the µLOT eyes was 9.5 pc/ms and it returned to normal in 30d postoperatively, with a value of 11.4 pc/ms. In the iStent eyes, ACF was 9.6 pc/ms preoperatively and it returned to normal by 7d postoperatively (11.2 pc/ms at day 7), demonstrating that postoperative inflammation was less in the iStent eyes. The corneal ECD in both groups was not significantly decreased. CONCLUSION In this study, iStent and µLOT are both effective through 12mo of follow-up. Safety is more favorable in the iStent eyes, based on early anterior chamber inflammation.
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Affiliation(s)
- Naoto Tokuda
- Department of Ophthalmology, St Marianna University School of Medicine, 2-16-1 Sugao Miyamae-ku Kawasaki-shi, Kanagawa 216-8851, Japan
| | - Yasushi Kitaoka
- Department of Ophthalmology, St Marianna University School of Medicine, 2-16-1 Sugao Miyamae-ku Kawasaki-shi, Kanagawa 216-8851, Japan
| | - Ayaka Tsukamoto
- Department of Ophthalmology, St Marianna University School of Medicine, 2-16-1 Sugao Miyamae-ku Kawasaki-shi, Kanagawa 216-8851, Japan
| | - Yasuhiro Toyoda
- Department of Ophthalmology, St Marianna University School of Medicine, 2-16-1 Sugao Miyamae-ku Kawasaki-shi, Kanagawa 216-8851, Japan
| | - Yusuke Yamada
- Department of Ophthalmology, St Marianna University School of Medicine, 2-16-1 Sugao Miyamae-ku Kawasaki-shi, Kanagawa 216-8851, Japan
| | - Kana Sase
- Department of Ophthalmology, St Marianna University School of Medicine, 2-16-1 Sugao Miyamae-ku Kawasaki-shi, Kanagawa 216-8851, Japan
| | - Hitoshi Takagi
- Department of Ophthalmology, St Marianna University School of Medicine, 2-16-1 Sugao Miyamae-ku Kawasaki-shi, Kanagawa 216-8851, Japan
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11
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Panigrahi A, Huang AS, Arora M, Kumari S, Mahalingam K, Gupta V, Gupta S. Indocyanine Green Aided Schlemm Canal Identification During Gonioscopic Assisted Transluminal Trabeculotomy. J Glaucoma 2022; 31:e69-e71. [PMID: 35513892 PMCID: PMC9378495 DOI: 10.1097/ijg.0000000000002047] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 04/27/2022] [Indexed: 02/04/2023]
Abstract
Performing procedures like gonioscopic assisted transluminal trabeculotomy in eyes with congenital glaucoma may be difficult many a times due to difficult visualization of angle structures. Inaccurate identification of the angle landmark may lead to various inadvertent surgical complications. Hence, there is a need for techniques to improve visualization of surgical landmarks during these procedures. In this study, 0.2% indocyanine green was used to stain the trabecular meshwork before the surgeon proceeded with gonioscopic assisted transluminal trabeculotomy. It yielded excellent differentiation of the trabecular meshwork by imparting a bright green hue. This led to successful identification of the site of incision and subsequent 360 degrees cannulation of Schlemm canal in 5/5 cases. Indocyanine green aided Schlemm canal identification is helpful in children with congenital glaucoma undergoing angle surgeries, especially in eyes with poor structure differentiation.
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Affiliation(s)
- Arnav Panigrahi
- Dr Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS New Delhi
| | - Alex S Huang
- The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, CA, USA
| | - Monika Arora
- Dr Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS New Delhi
| | - Somya Kumari
- Dr Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS New Delhi
| | | | - Viney Gupta
- Dr Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS New Delhi
| | - Shikha Gupta
- Dr Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS New Delhi
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12
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Sosnowik S, Swain DL, Fan S, Toris CB, Gong H. Morphological changes to Schlemm's canal and the distal aqueous outflow pathway in monkey eyes with laser-induced ocular hypertension. Exp Eye Res 2022; 219:109030. [PMID: 35283108 PMCID: PMC9133064 DOI: 10.1016/j.exer.2022.109030] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 01/31/2022] [Accepted: 03/06/2022] [Indexed: 11/04/2022]
Abstract
Though roughly 30-50% of aqueous outflow resistance resides distal to Schlemm's canal (SC), the morphology of the conventional outflow pathway distal to SC has not been thoroughly evaluated. This study examined the morphological changes along proximal and distal aspects of the conventional aqueous outflow pathway and their association with decreased outflow facility in an experimental model of glaucoma in cynomolgus macaques. Nd:YAG laser burns were made to 270-340 degrees of the trabecular meshwork (TM) of one eye (n = 6) or both eyes (n = 2) of each monkey to induce ocular hypertension. Distinct regions of the TM were left unlasered. Contralateral eyes (n = 5) were not lasered and were utilized as controls. Monkeys were sacrificed ≥58 months after their last laser treatment. All eyes were enucleated and perfused at 15 mmHg for 30 min to measure outflow facility. Two pairs of eyes were also perfused with fluorescein to examine segmental outflow. All eyes underwent perfusion-fixation for 1 h. Anterior segments were cut into radial wedges and processed for light and electron microscopy. Width, height, and cross-sectional area (CSA) of SC were compared between high- and low-flow regions of control eyes, and between non-lasered regions of laser-treated eyes and control eyes. Number and CSA of intrascleral veins (ISVs) were compared between non-lasered and lasered regions of laser-treated eyes and control eyes, and between high- and low-flow regions of control eyes. Scleral collagen fibril diameter was compared between control eyes and lasered and non-lasered regions of laser-treated eyes. Median outflow facility was significantly decreased in laser-treated eyes compared to control eyes (P = 0.02). Median CSA and height of SC were smaller in high-flow regions than low-flow regions of control eyes (P < 0.05). Median width of SC was not significantly different between high- and low-flow regions of control eyes (P > 0.05). Median CSA, width, and height of SC were not different between non-lasered regions and control eyes (P > 0.05). SC was partially or completely obliterated in lasered regions. Median number of ISVs was significantly decreased in lasered regions compared to non-lasered regions (P < 0.01) and control eyes (P < 0.01). Median CSA of ISVs did not differ between these groups (P > 0.05). Median number and CSA of ISVs were not significantly different between high- and low-flow regions of control eyes (P > 0.05). Lasered regions displayed looser scleral stroma and smaller median diameter of collagen fibrils adjacent to the TM compared to non-lasered regions (P < 0.05) and control eyes (P < 0.05). Dense TM, partial to complete obliteration of SC, and a decreased number of patent ISVs may account in part for the decreased outflow facility in monkey eyes with laser-induced ocular hypertension. The significance of changes in scleral structure in laser-treated eyes warrants further investigation.
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Affiliation(s)
- Shayna Sosnowik
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USA
| | - David L Swain
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USA; Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, USA
| | - Shan Fan
- Department of Ophthalmology and Visual Science, University of Nebraska Medical Center, Omaha, NE, USA
| | - Carol B Toris
- Department of Ophthalmology and Visual Science, University of Nebraska Medical Center, Omaha, NE, USA; Department of Ophthalmology and Visual Sciences, The Ohio State University, Columbus, OH, USA
| | - Haiyan Gong
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USA; Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, USA.
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13
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Gan J, Sng CCA, Ke M, Chieh CS, Tan B, Schmetterer L, Ang M. Anterior Segment Optical Coherence Tomography Angiography Following Trabecular Bypass Minimally Invasive Glaucoma Surgery. Front Med (Lausanne) 2022; 9:830678. [PMID: 35321475 PMCID: PMC8936187 DOI: 10.3389/fmed.2022.830678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 01/27/2022] [Indexed: 11/13/2022] Open
Abstract
ObjectiveTo assess anterior segment optical coherence tomography angiography (AS-OCTA) imaging of the episcleral vessels before and after trabecular bypass minimally invasive glaucoma surgery (MIGS).DesignA prospective, clinical, single-centre, single-arm pilot feasibility study conducted at National University Hospital, Singapore.SubjectsPatients with primary glaucomatous optic neuropathy undergoing Hydrus Microstent (Ivantis Inc., Irvine, CA, USA) implantation, who require at least one intra-ocular pressure-lowering medication. One or two eyes per patient may be enrolled.MethodsWe performed AS-OCTA (Nidek RS-3000 Advance 2, Gamagori, Japan) pre- and up to 6 months post-MIGS implantation using a standard protocol in all cornealimbal quadrants, to derive episcleral vessel densities (VD) using a previously described technique.Main Outcome MeasuresEpiscleral VD pre- and post-surgery, in sectors with and without the implant.ResultsWe obtained serial AS-OCTA images in 25 eyes undergoing MIGS implantation (23 subjects, mean age 70.3 ± 1.5, 61% female) with mean preoperative intraocular pressure (IOP) of 15.5 mmHg ± 4.0. We observed reductions in postoperative episcleral VD compared to preoperative VD at month 1 (mean difference −3.2, p = 0.001), month 3 (mean difference −2.94, p = 0.004) and month 6 (mean difference −2.19, p = 0.039) in sectors with implants (overall 6 month follow-up, p = 0.011). No significant changes were detected in episcleral VD in the sectors without implants (p = 0.910).ConclusionIn our pilot study, AS-OCTA was able to detect changes in the episcleral VD following trabecular bypass MIGS, which may be a useful modality to evaluate surgical outcomes if validated in future studies.
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Affiliation(s)
- Jinyuan Gan
- Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Chelvin C. A. Sng
- Singapore National Eye Centre, Singhealth, Singapore Eye Research Institute, Singapore, Singapore
- Department of Ophthalmology, National University Hospital, Singapore, Singapore
| | - Mengyuan Ke
- Singapore National Eye Centre, Singhealth, Singapore Eye Research Institute, Singapore, Singapore
| | - Chew Shi Chieh
- Department of Ophthalmology, National University Hospital, Singapore, Singapore
| | - Bingyao Tan
- Singapore National Eye Centre, Singhealth, Singapore Eye Research Institute, Singapore, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore, Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
| | - Leopold Schmetterer
- Duke-NUS Graduate Medical School, Singapore, Singapore
- Singapore National Eye Centre, Singhealth, Singapore Eye Research Institute, Singapore, Singapore
- Department of Ophthalmology, National University Hospital, Singapore, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore, Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
| | - Marcus Ang
- Duke-NUS Graduate Medical School, Singapore, Singapore
- Singapore National Eye Centre, Singhealth, Singapore Eye Research Institute, Singapore, Singapore
- *Correspondence: Marcus Ang
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14
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Dada T, Bukke AN. Aqueous angiography guided ab interno trabecular surgery for open-angle glaucoma. BMJ Case Rep 2022; 15:e248261. [PMID: 34996772 PMCID: PMC8744117 DOI: 10.1136/bcr-2021-248261] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2021] [Indexed: 11/03/2022] Open
Affiliation(s)
- Tanuj Dada
- Ophthalmology, RPCentre for Ophthalmic Sciences, AIIMS, New Delhi, India
| | - Anand Naik Bukke
- Ophthalmology, RPCentre for Ophthalmic Sciences, AIIMS, New Delhi, India
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15
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Dada T, Verma S, Bukke AN, Strohmaier CA, Huang AS. Aqueous Angiography-guided Minimally Invasive Glaucoma Surgery. J Curr Glaucoma Pract 2022; 16:1-3. [PMID: 36060039 PMCID: PMC9385386 DOI: 10.5005/jp-journals-10078-1367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
How to cite this article: Dada T, Verma S, Bukke AN, et al. Aqueous Angiography-guided Minimally Invasive Glaucoma Surgery. J Curr Glaucoma Pract 2022;16(1):1-3.
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Affiliation(s)
- Tanuj Dada
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India,Tanuj Dada, All India Institute of Medical Sciences, New Delhi, India, e-mail:
| | - Saurabh Verma
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Anand N Bukke
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | | | - Alex S Huang
- Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States of America
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16
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Burn JB, Huang AS, Weber A, Komáromy AM, Pirie CG. Aqueous angiography in pre-glaucomatous and glaucomatous ADAMTS10-mutant canine eyes: A pilot study. Vet Ophthalmol 2021; 25 Suppl 1:72-83. [PMID: 34724299 PMCID: PMC9056585 DOI: 10.1111/vop.12938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 08/30/2021] [Accepted: 09/06/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate intravenous scleral and intracameral aqueous angiography in normotensive (n = 4) and hypertensive glaucomatous (n = 6) ADAMTS10-mutant canine eyes. ANIMALS STUDIED Ten ADAMTS10-mutant dogs were used in this study. PROCEDURES Dogs were sedated and one eye from each dog underwent scleral angiography following intravenous injection of 0.25% indocyanine green (ICG). After a 24-h recovery period, the same eye underwent aqueous angiography via intracameral administration of ICG. Imaging of identical scleral sectors from the same eye was performed using a Heidelberg Spectralis® Confocal Scanning Laser Ophthalmoscope. Intrascleral vessel depth and lumen diameters were measured using Heidelberg Spectralis® optical coherence tomography and computer software. RESULTS Scleral angiography permitted visualization of vascular components associated with conventional aqueous humor outflow pathways with an average time from injection to fluorescence of 35.8 ± 10.6 s (mean ± SD). Two normotensive eyes (2/10;20%) demonstrated turbulent dye movement, while 4 hypertensive eyes (4/10;40%) exhibited laminar flow. Aqueous angiography demonstrated dye fluorescence within the post-trabecular conventional aqueous humor outflow pathways in all 10 eyes at 34.3 ± 11.0 s post-injection. Sectoral and dynamic outflow patterns were observed primarily within the superotemporal sector in nine eyes (9/10; 90%). Seven eyes (7/10; 70%) demonstrated pulsatile dye movement and five eyes (5/10; 50%) exhibited laminar flow. The degree of laminar movement of dye was greatest in hypertensive eyes. Vessel lumen diameters measured 133.85 ± 28.36 µm and 161.18 ± 6.02 µm in hypertensive and normotensive eyes, respectively. CONCLUSIONS Aqueous angiography allowed for visualization of fluorescent dye in the superotemporal sclera. Laminar flow and smaller lumen vessels were observed mainly in hypertensive eyes.
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Affiliation(s)
| | | | - Arthur Weber
- Michigan State University, East Lansing, Michigan, USA
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17
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Telle MR, Snyder KC, Oikawa K, Nilles JP, Gehrke S, Teixeira LBC, Kiland JA, Huang A, McLellan GJ. Development and validation of methods to visualize conventional aqueous outflow pathways in canine primary angle closure glaucoma. Vet Ophthalmol 2021; 25 Suppl 1:84-95. [PMID: 34581493 PMCID: PMC8958177 DOI: 10.1111/vop.12943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/14/2021] [Accepted: 09/17/2021] [Indexed: 11/30/2022]
Abstract
PURPOSE Angle closure glaucoma (PACG) is highly prevalent in dogs and is often refractory to medical therapy. We hypothesized that pathology affecting the post-trabecular conventional aqueous outflow pathway contributes to persistent intraocular pressure (IOP) elevation in dogs with PACG. The goal of this study was to determine the potential for aqueous angiography (AA) and optical coherence tomography (OCT) to identify abnormalities in post-trabecular aqueous outflow pathways in canine PACG. METHODS AA and anterior segment OCT (Spectralis HRA + OCT) were performed ex vivo in 19 enucleated canine eyes (10 normal eyes and 9 irreversibly blind eyes from canine patients enucleated for management of refractory PACG). Eyes were cannulated and maintained at physiologic IOP (10-20 mmHg) prior to intracameral infusion of fluorescent tracer. OCT scleral line scans were acquired in regions of high and low perilimbal AA signal. Eyes were then perfusion fixed and cryosections prepared from 10/10 normal and 7/9 PACG eyes and immunolabeled for a vascular endothelial marker. RESULTS Normal canine eyes showed segmental, circumferential limbal AA signal, whereas PACG eyes showed minimal or no AA signal. AA signal correlated with scleral lumens on OCT in normal dogs, but lumens were generally absent or flattened in PACG eyes. Collapsed vascular profiles were identified in tissue sections from PACG eyes, including those in which no lumens were identified on AA and OCT. CONCLUSIONS In canine eyes with PACG, distal aqueous outflow channels are not identifiable by AA, despite normalization of their IOP, and intra-scleral vascular profiles are collapsed on OCT and histopathology.
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Affiliation(s)
- Mary Rebecca Telle
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kevin C Snyder
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Ophthalmology & Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kazuya Oikawa
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Ophthalmology & Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jacob P Nilles
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Shaile Gehrke
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Leandro B C Teixeira
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Julie A Kiland
- Department of Ophthalmology & Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Alex Huang
- Shiley Eye Institute, The Viterbi Family Department of Ophthalmology, University of California, San Diego, California, USA
| | - Gillian J McLellan
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Ophthalmology & Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
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18
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iStent inject: comprehensive review. J Cataract Refract Surg 2021; 47:385-399. [PMID: 32842078 DOI: 10.1097/j.jcrs.0000000000000325] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/22/2020] [Indexed: 11/26/2022]
Abstract
Microinvasive glaucoma surgeries (MIGSs) are new surgical procedures for treatment of glaucoma. They aim to safely and effectively reduce intraocular pressure (IOP) with minimal trauma to the eye and less complications. The first-generation iStent is the first approved ab interno MIGS implant for management of open-angle glaucoma. It works by allowing aqueous humor to drain directly from the anterior chamber into Schlemm canal bypassing the trabecular meshwork, the major site of outflow resistance. The second-generation iStent inject is the smallest available trabecular device that occupies less than 0.5 mm. It is designed to facilitate the surgical technique and allow simultaneous implantation of 2 stents, aiming for more IOP reduction. This review examines publications about the iStent inject, focusing on the device's efficacy, safety, and comparison with the first generation iStent. Both devices were found to be a safe and effective tool in management of open-angle glaucoma.
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19
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Johnstone M, Xin C, Tan J, Martin E, Wen J, Wang RK. Aqueous outflow regulation - 21st century concepts. Prog Retin Eye Res 2021; 83:100917. [PMID: 33217556 PMCID: PMC8126645 DOI: 10.1016/j.preteyeres.2020.100917] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 12/24/2022]
Abstract
We propose an integrated model of aqueous outflow control that employs a pump-conduit system in this article. Our model exploits accepted physiologic regulatory mechanisms such as those of the arterial, venous, and lymphatic systems. Here, we also provide a framework for developing novel diagnostic and therapeutic strategies to improve glaucoma patient care. In the model, the trabecular meshwork distends and recoils in response to continuous physiologic IOP transients like the ocular pulse, blinking, and eye movement. The elasticity of the trabecular meshwork determines cyclic volume changes in Schlemm's canal (SC). Tube-like SC inlet valves provide aqueous entry into the canal, and outlet valve leaflets at collector channels control aqueous exit from SC. Connections between the pressure-sensing trabecular meshwork and the outlet valve leaflets dynamically control flow from SC. Normal function requires regulation of the trabecular meshwork properties that determine distention and recoil. The aqueous pump-conduit provides short-term pressure control by varying stroke volume in response to pressure changes. Modulating TM constituents that regulate stroke volume provides long-term control. The aqueous outflow pump fails in glaucoma due to the loss of trabecular tissue elastance, as well as alterations in ciliary body tension. These processes lead to SC wall apposition and loss of motion. Visible evidence of pump failure includes a lack of pulsatile aqueous discharge into aqueous veins and reduced ability to reflux blood into SC. These alterations in the functional properties are challenging to monitor clinically. Phase-sensitive OCT now permits noninvasive, quantitative measurement of pulse-dependent TM motion in humans. This proposed conceptual model and related techniques offer a novel framework for understanding mechanisms, improving management, and development of therapeutic options for glaucoma.
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Affiliation(s)
| | - Chen Xin
- Department of Ophthalmology, Beijing Anzhen Hospital, Capital Medical University, China.
| | - James Tan
- Doheny Eye Institute and UCLA Department of Ophthalmology, USA.
| | | | | | - Ruikang K Wang
- Department of Ophthalmology, University of Washington, USA; Department of Bioengineering, University of Washington, USA.
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20
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Toris CB, Gagrani M, Ghate D. Current methods and new approaches to assess aqueous humor dynamics. EXPERT REVIEW OF OPHTHALMOLOGY 2021. [DOI: 10.1080/17469899.2021.1902308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Carol B. Toris
- Dept. Of Ophthalmology and Visual Science, University of Nebraska Medical Center, Omaha, NE, USA
- Dept. Of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH USA
| | - Meghal Gagrani
- Dept. Of Ophthalmology and Visual Science, University of Nebraska Medical Center, Omaha, NE, USA
| | - Deepta Ghate
- Dept. Of Ophthalmology and Visual Science, University of Nebraska Medical Center, Omaha, NE, USA
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21
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Gupta V, Singh A, Pandya I, Sofi R, Sen S, Somarajan BI, Gupta S, Nag TC. Differences in outflow channels between two eyes of unilateral primary congenital glaucoma. Acta Ophthalmol 2021; 99:187-194. [PMID: 32701215 DOI: 10.1111/aos.14540] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 05/12/2020] [Accepted: 06/13/2020] [Indexed: 12/30/2022]
Abstract
PURPOSE Primary congenital glaucoma (PCG) occurs in only one eye in some patients. We aimed to characterize anatomical features of the angle and Schlemm's canal (SC) in vivo among fellow eyes of patients with unilateral primary congenital glaucoma. METHODS Both eyes of 33 children with unilateral PCG and 30 healthy, age-matched children, old enough to co-operate were analysed using high-resolution anterior segment spectral domain (SD) OCT. Subgroup analysis was done for the presence/absence of angle dysgenesis as defined by the presence of abnormal tissue/hyper-reflective membrane within angle recess and/or the absence of SC. Other anatomical landmarks differentiating the fellow eyes from eyes with glaucoma were also evaluated and compared with healthy subjects. RESULTS The presence of abnormal tissue at the angle and/or a hyper-reflective membranous structure covering the meshwork was seen in all affected PCG eyes (100%) and in 21 (63%) unaffected fellow eyes; p = 0.001. The SC could be seen in 8 (24%) affected in comparison with 29 (88%) fellow unaffected eyes; p = 0.001. The ASOCT scans of 54 (90%) healthy eyes and 3 (9%) fellow PCG eyes revealed a direct communication of anterior portion of the SC with the anterior chamber. Among the fellow eyes, a communication of the supraciliary space with anterior chamber could be discerned in 26 eyes (79%). CONCLUSIONS Despite angle dysgenesis, outflow channels such as the uveoscleral or a direct communication of SC with the anterior chamber play a role in preventing the development of glaucoma in fellow eyes of unilateral PCG.
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Affiliation(s)
- Viney Gupta
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences All India Institute of Medical Sciences New Delhi India
| | - Abhishek Singh
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences All India Institute of Medical Sciences New Delhi India
| | - Ishan Pandya
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences All India Institute of Medical Sciences New Delhi India
| | - Rayees Sofi
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences All India Institute of Medical Sciences New Delhi India
| | - Seema Sen
- Department of Ocular Pathology Dr. Rajendra Prasad Centre for Ophthalmic Sciences All India Institute of Medical Sciences New Delhi India
| | - Bindu I. Somarajan
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences All India Institute of Medical Sciences New Delhi India
| | - Shikha Gupta
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences All India Institute of Medical Sciences New Delhi India
| | - Tapas C. Nag
- Department of Anatomy and Electron Microscopy Facility All India Institute of Medical Sciences New Delhi India
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22
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Kim SJ, Moon SW, Lee JW. One-year Result of Trabeculectomy Following a Failed Trabecular Micro-bypass Stent. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2021. [DOI: 10.3341/jkos.2021.62.2.243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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23
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Lee JY, Akiyama G, Saraswathy S, Xie X, Pan X, Hong YK, Huang AS. Aqueous humour outflow imaging: seeing is believing. Eye (Lond) 2020; 35:202-215. [PMID: 33060830 DOI: 10.1038/s41433-020-01215-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 09/27/2020] [Accepted: 09/29/2020] [Indexed: 12/22/2022] Open
Abstract
Elevated intraocular pressure (IOP) is the primary risk factor for blindness in glaucoma. IOP is determined by many factors including aqueous humour production and aqueous humour outflow (AHO), where AHO disturbance represents the primary cause of increased IOP. With the recent development of new IOP lowering drugs and Minimally Invasive Glaucoma Surgeries (MIGS), renewed interest has arisen in shedding light on not only how but where AHO is occurring for the trabecular/conventional, uveoscleral/unconventional, and subconjunctival outflow pathways. Historical studies critical to understanding outflow anatomy will be presented, leading to the development of modern imaging methods. New biological behaviours uncovered by modern imaging methods will be discussed with relevance to glaucoma therapies emphasized.
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Affiliation(s)
- Jong Yeon Lee
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.,Department of Ophthalmology, Gachon University, College of Medicine, Gil Medical Center, Incheon, Korea
| | - Goichi Akiyama
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.,Jikei School of Medicine, Tokyo, Japan.,Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Sindhu Saraswathy
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Xiaobin Xie
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.,Eye Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiaojing Pan
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.,Qindao Eye Hospital of Shandong First Medical University, Shandong Eye Institute, Qindao, China
| | - Young-Kwon Hong
- Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Alex S Huang
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.
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24
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Gillmann K, Mansouri K. Minimally Invasive Surgery, Implantable Sensors, and Personalized Therapies. J Ophthalmic Vis Res 2020; 15:531-546. [PMID: 33133445 PMCID: PMC7591837 DOI: 10.18502/jovr.v15i4.7792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 07/08/2020] [Indexed: 01/02/2023] Open
Abstract
Glaucoma management has changed dramatically over the last decades, through clinical advances and technological revolutions. This review discusses the latest innovations and challenges faced in the field around three major axes: minimally-invasive glaucoma surgery (MIGS), implantable sensors and injectable therapeutics. Indeed, the vast number of recently developed MIGS techniques has not only provided clinicians with a wide range of therapeutic options, but they have also enabled them to adjust their therapies more finely which may have contributed a more patient-centric decision-making process. Yet, despite considerable advances in the field, the wide heterogeneity in clinical trial designs blurs the surgical outcomes, specificities and indications. Thus, more high-quality data are required to make the choice of a specific MIGS procedure more than an educated guess. Beyond the scope of MIGS, the potential of IOP telemetry for self-assessment of IOP-control through implantable sensors is developing into a real option for clinicians and an empowering opportunity for patients. Indeed, providing patients with direct feedback enables them to take control and have a clearer representation of their care, in turn leading to a better control of the disease. However, there are potential issues with self-monitoring of IOP, such as increased anxiety levels induced by measured IOP fluctuations and peaks, leading to patients self-treating during IOP spikes and additional office visits. Furthermore, the advent of implantable therapeutics may soon provide yet another step towards personalized glaucoma treatment, by offering not only an efficient alternative to current treatments, but also a therapeutic option that may better adapt to patients' lifestyle. After several decades of relative stagnation through the last century, glaucoma has now entered what many view as a golden age for the specialty. Like every revolution, this one brings its fair share of uncertainty, clinical questioning and uneasy periods of adaptation to ever-changing expectations. Yet, while it is impossible to guess what the landscape of glaucoma surgery will be like in ten or fifteen years, data suggest a bright outlook both for patients and clinicians.
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Affiliation(s)
- Kevin Gillmann
- Glaucoma Research Center, Montchoisi Clinic, Swiss Visio, Lausanne, Switzerland
| | - Kaweh Mansouri
- Glaucoma Research Center, Montchoisi Clinic, Swiss Visio, Lausanne, Switzerland
- Department of Ophthalmology, University of Colorado School of Medicine, Denver, CO, USA
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25
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Evaluation of Blood-filling Patterns in Schlemm Canal for Trabectome Surgery. J Glaucoma 2020; 29:1101-1105. [PMID: 32890107 DOI: 10.1097/ijg.0000000000001646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PRéCIS:: Regardless of the blood-filling patterns in Schlemm canal (SC) before the trabecular meshwork (TM) ablation, the trabectome surgery, combined with phacoemulsification, is effective for mild to moderate primary open-angle glaucoma patients. PURPOSE The purpose of this study was to evaluate the association between trabectome surgery outcomes and the blood filling patterns in SC before TM ablation. MATERIALS AND METHODS This retrospective cohort study included 105 eyes of 84 Japanese primary open-angle glaucoma patients who had undergone trabectome surgery in combination with cataract surgery. Provocative gonioscopy was performed before TM ablation to classify the blood filling patterns in SC into 3 groups: no filling (group 1); patchy/irregular filling (group 2); and complete filling (group 3). The subjects were divided into 3 groups according to the blood filling patterns and the trabectome surgery outcomes were compared, including intraocular pressure (IOP), the percentage reduction in IOP, surgical success rate, and the number of glaucoma medications. Success was defined by IOP ≤15 mm Hg and a >20% reduction in IOP with/without glaucoma medication, and without additional glaucoma surgery after trabectome surgery combined with cataract surgery. RESULTS Twenty-four eyes were assigned to group 1, 48 to group 2, and 33 to group 3. Between-group analyses showed no significant intergroup differences in age (P=0.213), preoperative mean deviation (P=0.505), preoperative and postoperative IOP (P=0.941 and 0.458, respectively), preoperative and postoperative number of glaucoma medications (P=0.805 and 0.077, respectively), percentage IOP reduction (P=0.256), and success rates (P=0.540). CONCLUSION Trabectome surgery is effective for mild to moderate primary open-angle glaucoma patients, independent of the blood-filling patterns in SC before the TM ablation.
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26
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Aqueous outflow imaging techniques and what they tell us about intraocular pressure regulation. Eye (Lond) 2020; 35:216-235. [PMID: 32826996 DOI: 10.1038/s41433-020-01136-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 07/19/2020] [Accepted: 08/07/2020] [Indexed: 02/06/2023] Open
Abstract
Recent advances in the medical and surgical management of open-angle glaucoma have increased the number of treatment options available. Several new intraocular pressure (IOP)-lowering treatments target the conventional aqueous outflow (AO) system. However, success rates are variable and outcomes in individual patients are often difficult to predict. Variable treatment responses remain unexplained and highlight deficiencies in our current understanding of AO regulation and IOP homeostasis. Imaging is often relied upon to confirm diagnoses and monitor treatment responses in other ocular and systemic pathologies. As yet no suitable AO imaging tool has been developed to fulfil this role in glaucoma. A variety of imaging techniques have been used to study the AO tracts of humans and animals in ex vivo and in vivo eyes. In this review, results from novel imaging techniques that assess aqueous drainage through the episcleral venous system are considered and we argue these provide new insights into AO regulation. We suggest that the ability to objectively measure AO responses to interventions would be a significant clinical advance, and we have demonstrated that this can be achieved with direct visualisation of aqueous drainage. We predict that the evolution of AO imaging technology will continue to reveal critical components of AO and IOP regulation, and that personalised IOP-lowering treatment in glaucoma care may well become a reality in the near future.
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27
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Burn JB, Huang AS, Weber AJ, Komáromy AM, Pirie CG. Aqueous Angiography in Normal Canine Eyes. Transl Vis Sci Technol 2020; 9:44. [PMID: 32934894 PMCID: PMC7463224 DOI: 10.1167/tvst.9.9.44] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 08/02/2020] [Indexed: 01/09/2023] Open
Abstract
Purpose To conduct aqueous angiography (AA) using a clinically applicable technique in normal dogs and to compare findings to intravenous scleral angiography (SA). Methods We examined 10 canine cadaver eyes and 12 eyes from live normal dogs. A gravity-fed trocar system delivered 2% sodium fluorescein and 0.25% indocyanine green (ICG) intracamerally (IC) in cadaver eyes. In vivo AA was subsequently performed in one eye of each of the 12 dogs via IC bolus of ICG under sedation. The same 12 dogs received SA via intravenous ICG (mean ± SD) 10.7 ± 3.3 days later. Identical scleral sectors were imaged using a Spectralis confocal scanning laser ophthalmoscope. Results The gravity-fed trocar system permitted visualization of the conventional aqueous humor outflow (CAHO) pathways in cadaver eyes, but not in vivo. Fluorescence was observed superonasally in four of the 10 cadaver eyes within 24.0 ± 3.6 seconds. A single IC bolus of ICG showed CAHO pathways in vivo, demonstrating sectoral outflow patterns in the superotemporal sclera in 10 of the 12 eyes within 35.0 ± 4.3 seconds; four of the 12 eyes exhibited pulsatile aqueous movement. SA exhibited fluorescence patterns comparable to AA with weak pulsatile aqueous humor outflow. Conclusions Angiography (AA or SA) in dogs permits visualization of the CAHO pathway and its vascular components in vivo. AA may be a more useful modality to assess aqueous humor outflow. Translational Relevance Intracameral AA has potential utility for evaluating CAHO in vivo in dogs, an important animal model species.
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Affiliation(s)
- Jessica B. Burn
- Michigan State University Veterinary Medical Center, East Lansing, MI, USA
| | - Alex S. Huang
- Doheny Eye Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Arthur J. Weber
- Michigan State University Veterinary Medical Center, East Lansing, MI, USA
| | - Andras M. Komáromy
- Michigan State University Veterinary Medical Center, East Lansing, MI, USA
| | - Chris G. Pirie
- Michigan State University Veterinary Medical Center, East Lansing, MI, USA
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Abstract
Spaceflight-associated neuro-ocular syndrome (SANS) describes a series of morphologic and functional ocular changes in astronauts first reported by Mader and colleagues in 2011. SANS is currently clinically defined by the development of optic disc edema during prolonged exposure to the weightless (microgravity) environment, which currently occurs on International Space Station (ISS). However, as improvements in our understanding of the ocular changes emerge, the definition of SANS is expected to evolve. Other ocular SANS signs that arise during and after ISS missions include hyperopic shifts, globe flattening, choroidal/retinal folds, and cotton wool spots. Over the last 10 years, ~1 in 3 astronauts flying long-duration ISS missions have presented with ≥1 of these ocular findings. Commensurate with research that combines disparate specialties (vision biology and spaceflight medicine), lessons from SANS investigations may also yield insight into ground-based ocular disorders, such as glaucomatous optic neuropathy that may have the potential to lessen the burden of this irreversible cause of vision loss on Earth.
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29
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Akiyama G, Saraswathy S, Bogarin T, Pan X, Barron E, Wong TT, Kaneko MK, Kato Y, Hong Y, Huang AS. Functional, structural, and molecular identification of lymphatic outflow from subconjunctival blebs. Exp Eye Res 2020; 196:108049. [PMID: 32387381 PMCID: PMC7328765 DOI: 10.1016/j.exer.2020.108049] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/05/2020] [Accepted: 04/27/2020] [Indexed: 01/26/2023]
Abstract
The purpose of this study is to evaluate outflow pathways from subconjunctival blebs and to identify their identity. Post-mortem porcine (n = 20), human (n = 1), and bovine (n = 1) eyes were acquired, and tracers (fluorescein, indocyanine green, or fixable/fluorescent dextrans) were injected into the subconjunctival space to create raised blebs where outflow pathways were visualized qualitatively and quantitatively. Rodents with fluorescent reporter transgenes were imaged for structural comparison. Concurrent optical coherence tomography (OCT) was obtained to study the structural nature of these pathways. Using fixable/fluorescent dextrans, tracers were trapped to the bleb outflow pathway lumen walls for histological visualization and molecular identification using immunofluorescence against lymphatic and blood vessel markers. Bleb outflow pathways could be observed using all tracers in all species. Quantitative analysis showed that the nasal quadrant had more bleb-related outflow pathways compared to the temporal quadrant (nasal: 1.9±0.3 pathways vs. temporal: 0.7±0.2 pathways; p = 0.003). However, not all blebs resulted in an outflow pathway (0-pathways = 18.2%; 1-pathway = 36.4%; 2-pathways = 38.6%; and 3-pathways = 6.8%). Outflow signal was validated as true luminal pathways using optical coherence tomography and histology. Bicuspid valves were identified in the direction of flow in porcine eyes. Immunofluorescence of labeled pathways demonstrated a lymphatic (Prox-1 and podoplanin) but not a blood vessel (CD31) identity. Therefore, subconjunctival bleb outflow occurs in discrete luminal pathways. They are lymphatic as assessed by structural identification of valves and molecular identification of lymphatic markers. Better understanding of lymphatic outflow may lead to improved eye care for glaucoma surgery and ocular drug delivery.
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Affiliation(s)
- Goichi Akiyama
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Jikei School of Medicine, Tokyo, Japan
| | - Sindhu Saraswathy
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Thania Bogarin
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Xiaojing Pan
- Qingdao Eye Hospital, Shandong Eye Institute, Shandong First Medical University, Qingdao, China
| | - Ernesto Barron
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Tina T Wong
- Singapore National Eye Center and Singapore Research Institute, Singapore, Singapore
| | - Mika K Kaneko
- Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Yukinari Kato
- Tohoku University Graduate School of Medicine, Miyagi, Japan; New Industry Creation Hatchery Center, Tohoku University, Miyagi, Japan
| | - Young Hong
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Norris Comprehensive Cancer Center Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Alex S Huang
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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30
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Saraswathy S, Bogarin T, Barron E, Francis BA, Tan JCH, Weinreb RN, Huang AS. Segmental differences found in aqueous angiographic-determined high - and low-flow regions of human trabecular meshwork. Exp Eye Res 2020; 196:108064. [PMID: 32439396 DOI: 10.1016/j.exer.2020.108064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 05/04/2020] [Accepted: 05/05/2020] [Indexed: 01/28/2023]
Abstract
This work sought to compare aqueous angiographic segmental patterns with bead-based methods which directly visualize segmental trabecular meshwork (TM) tracer trapping. Additionally, segmental protein expression differences between aqueous angiographic-derived low- and high-outflow human TM regions were evaluated. Post-mortem human eyes (One Legacy and San Diego eye banks; n = 15) were perfused with fluorescent tracers (fluorescein [2.5%], indocyanine green [0.4%], and/or fluorescent microspheres). After angiographic imaging (Spectralis HRA+OCT; Heidelberg Engineering), peri-limbal low- and high-angiographic flow regions were marked. Aqueous angiographic segmental outflow patterns were similar to fluorescent microsphere TM trapping segmental patterns. TM was dissected from low- and high-flow areas and processed for immunofluorescence or Western blot and compared. Versican expression was relatively elevated in low-flow regions while MMP3 and collagen VI were relatively elevated in high-flow regions. TGF-β2, thrombospondin-1, TGF-β receptor1, and TGF-β downstream proteins such as α-smooth muscle actin were relatively elevated in low-flow regions. Additionally, fibronectin (FN) levels were unchanged, but the EDA isoform (FN-EDA) that is associated with fibrosis was relatively elevated in low-flow regions. These results show that segmental aqueous angiographic patterns are reflective of underlying TM molecular characteristics and demonstrate increased pro-fibrotic activation in low-flow regions. Thus, we provide evidence that aqueous angiography outflow visualization, the only tracer outflow imaging method available to clinicians, is in part representative of TM biology.
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Affiliation(s)
- Sindhu Saraswathy
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Thania Bogarin
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Ernesto Barron
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Brian A Francis
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - James C H Tan
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Robert N Weinreb
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology University of California, San Diego, CA, USA
| | - Alex S Huang
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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31
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Gillmann K, Mansouri K. Minimally Invasive Glaucoma Surgery: Where Is the Evidence? Asia Pac J Ophthalmol (Phila) 2020; 9:203-214. [PMID: 32501895 PMCID: PMC7299223 DOI: 10.1097/apo.0000000000000294] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 04/04/2020] [Indexed: 12/12/2022] Open
Abstract
PURPOSE The last decade has witnessed an unprecedented growth in glaucoma treatment options through the introduction of minimally invasive glaucoma surgeries (MIGS). The aim of the present review is to provide an understanding of the currently available MIGS and to examine what data are currently available to guide treatment choice. DESIGN Meta-analysis and systematic review of randomized and non-randomized control trials. METHODS Out of 2567 articles identified, a total of 77 articles were retained for analysis, including 28 comparative studies and 12 randomized control trials. Overall, 7570 eyes were included. When data permitted, the weighted mean difference in intraocular pressure reduction was calculated for comparison purposes. RESULTS Weighted mean intraocular pressure reductions from all analyzed studies were: 15.3% (iStent), 29.1% (iStent inject), 36.2% (ab interno canaloplasty), 34.4% (Hydrus), 36.5% (gonioscopically-assisted transluminal trabeculotomy), 24.0% (trabectome), 25.1% (Kahook dual blade), 30.2% (Cypass), 38.8% (XEN), and 50.0% (Preserflo). CONCLUSIONS One of the advantages of the heterogenous range of available MIGS options is the chance to tailor therapy in an individualized manner. However, high-quality data are required to make this choice more than an educated guess. Overall, this review confirms the efficiency of assessed MIGS compared with standalone phacoemulsification, but it highlights that only few studies compare different MIGS techniques and even fewer assess MIGS against criterion standard treatments. Current evidence, while non-negligible, is mostly limited to heterogenous nonrandomized studies and uncontrolled retrospective comparisons, with few quality randomized control trials. We suggest that future research should be comparative and include relevant comparators, standardized to report key outcome features, long-term to assess sustainability and late complications, and ideally randomized.
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Affiliation(s)
- Kevin Gillmann
- Glaucoma Research Center, Montchoisi Clinic, Swiss Visio, Lausanne, Switzerland
| | - Kaweh Mansouri
- Glaucoma Research Center, Montchoisi Clinic, Swiss Visio, Lausanne, Switzerland
- Department of Ophthalmology, University of Colorado School of Medicine, Denver, CO, USA
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32
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Snyder KC, Oikawa K, Williams J, Kiland JA, Gehrke S, Teixeira LBC, Huang AS, McLellan GJ. Imaging Distal Aqueous Outflow Pathways in a Spontaneous Model of Congenital Glaucoma. Transl Vis Sci Technol 2019; 8:22. [PMID: 31616579 PMCID: PMC6788461 DOI: 10.1167/tvst.8.5.22] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/26/2019] [Indexed: 01/01/2023] Open
Abstract
Purpose To validate the use of aqueous angiography (AA) in characterizing distal aqueous outflow pathways in normal and glaucomatous cats. Methods Ex vivo AA and optical coherence tomography (OCT) were performed in nine adult cat eyes (5 feline congenital glaucoma [FCG] and 4 normal), following intracameral infusion of 2.5% fluorescein and/or 0.4% indocyanine green (ICG) at physiologic intraocular pressure (IOP). Scleral OCT line scans were acquired in areas of high- and low-angiographic signal. Tissues dissected in regions of high- and low-AA signal, were sectioned and hematoxylin and eosin (H&E)-stained or immunolabeled (IF) for vascular endothelial and perivascular cell markers. Outflow vessel numbers and locations were compared between groups by Student's t-test. Results AA yielded circumferential, high-quality images of distal aqueous outflow pathways in normal and FCG eyes. No AA signal or scleral lumens were appreciated in one buphthalmic FCG eye, though collapsed vascular profiles were identified on IF. The remaining eight of nine eyes all showed segmental AA signal, distinguished by differences in time of signal onset. AA signal always corresponded with lumens seen on OCT. Numbers of intrascleral vessels were not significantly different between groups, but scleral vessels were significantly more posteriorly located relative to the limbus in FCG. Conclusions A capacity for distal aqueous humor outflow was confirmed by AA in FCG eyes ex vivo but with significant posterior displacement of intrascleral vessels relative to the limbus in FCG compared with normal eyes. Translational Relevance This report provides histopathologic correlates of advanced diagnostic imaging findings in a spontaneous model of congenital glaucoma.
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Affiliation(s)
- Kevin C Snyder
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, WI, USA
| | - Kazuya Oikawa
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, WI, USA.,Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, WI, USA
| | - Jeremy Williams
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, WI, USA
| | - Julie A Kiland
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, WI, USA
| | - Shaile Gehrke
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, WI, USA
| | - Leandro B C Teixeira
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, WI, USA
| | - Alex S Huang
- Doheny Eye Institute, and Department of Ophthalmology University of California, Los Angeles, CA, USA
| | - Gillian J McLellan
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, WI, USA.,Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, WI, USA
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33
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Bogarin T, Saraswathy S, Akiyama G, Xie X, Weinreb RN, Zheng J, Huang AS. Cellular and cytoskeletal alterations of scleral fibroblasts in response to glucocorticoid steroids. Exp Eye Res 2019; 187:107774. [PMID: 31449795 PMCID: PMC6759408 DOI: 10.1016/j.exer.2019.107774] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 08/22/2019] [Accepted: 08/22/2019] [Indexed: 11/16/2022]
Abstract
Steroid-induced ocular hypertension can be seen even after trabecular meshwork (TM) bypass/ablation. Thus, the purpose was to investigate steroid-response in cells distal to the TM by using primary scleral fibroblasts. Primary scleral cell cultures were generated using mid-depth scleral wedges from human donor corneo-scleral rims (n = 5) after corneal transplantation. Cells were treated with dexamethasone (DEX; 100 nM) and compared to media (MED)/vehicle (DMSO) controls. Cell size, shape, and migration were studied using the IncuCyte Live-Cell Analysis System. Cytoskeleton was compared using Alexa Fluor-568 Phalloidin and senescence tested by evaluating beta-galactosidase. Western blot comparison was performed for α-SMA, FKBP-51, fibronectin, phospho-myosin light chain, and myocilin. Scleral fibroblasts upregulated FKBP-51 in response to DEX indicating the existence of steroid-responsive pathways. Compared to controls, DEX-treated cells proliferated slower (~50%; p < 0.01-0.02), grew larger (~1.3-fold; p < 0.001), and migrated less (p = 0.01-0.006). Alexa Fluor 568 Phalloidin actin stress fiber labeling was more diffuse in DEX-treated cells (p = 0.001-0.004). DEX-treated cells showed more senescence compared to controls (~1.7-fold; p = 0.01-0.02). However, DEX-treated cells did not show increased cross-linked actin network formation or elevated myocilin/fibronectin/α-SMA/phospho-myosin light chain protein expression. For all parameters, MED- and DMSO-treated control cells were not significantly different. Primary scleral fibroblasts, grown from tissue collected immediately distal to the TM, demonstrated scleral-response behaviors that were similar to, but not identical with, classic TM steroid-response. Further study is needed to understand how these scleral cellular alterations may contribute to steroid-response IOP elevation after TM bypass/ablation surgery.
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Affiliation(s)
- Thania Bogarin
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Sindhu Saraswathy
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Goichi Akiyama
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Xiaobin Xie
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Eye Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Robert N Weinreb
- Hamilton Glaucoma Center, Shiley Eye Institute, and the Viterbi Family Department of Ophthalmology University of California, San Diego, CA, USA
| | - Jie Zheng
- Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Alex S Huang
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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34
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Andrew NH, Akkach S, Casson RJ. A review of aqueous outflow resistance and its relevance to microinvasive glaucoma surgery. Surv Ophthalmol 2019; 65:18-31. [PMID: 31425701 DOI: 10.1016/j.survophthal.2019.08.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 07/28/2019] [Accepted: 08/05/2019] [Indexed: 11/29/2022]
Abstract
Primary open-angle glaucoma is the leading cause of irreversible blindness worldwide, and intraocular pressure reduction remains the only proven treatment strategy. Elevated intraocular pressure occurs as the result of impaired aqueous humor outflow. Both a passive model and a dynamic model have been used to explain trabecular outflow resistance. The passive model posits that the trabecular meshwork acts as a static filter that exerts stable and passive resistance to outflow. In contrast, the dynamic model involves a "biomechanical pump." In recent years, the range of surgical management options for glaucoma has dramatically expanded, particularly the class of procedures known as microinvasive glaucoma surgery. These procedures typically target and enhance specific outflow routes. Optimal patient outcomes with microinvasive glaucoma surgery require a clear understanding of aqueous outflow and a surgical approach that is targeted to overcome the site of abnormal resistance in the individual. We review the anatomy and physiology of trabecular and suprachoroidal outflow that is of relevance to microinvasive glaucoma surgery-performing surgeons.
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Affiliation(s)
- Nicholas H Andrew
- South Australian Institute of Ophthalmology, University of Adelaide, Adelaide, South Australia, Australia
| | - Sarmad Akkach
- South Australian Institute of Ophthalmology, University of Adelaide, Adelaide, South Australia, Australia; Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia.
| | - Robert J Casson
- South Australian Institute of Ophthalmology, University of Adelaide, Adelaide, South Australia, Australia
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Gottschalk HM, Wecker T, Khattab MH, Fischer CV, Callizo J, Rehfeldt F, Lubjuhn R, Russmann C, Hoerauf H, van Oterendorp C. Lipid Emulsion-Based OCT Angiography for Ex Vivo Imaging of the Aqueous Outflow Tract. Invest Ophthalmol Vis Sci 2019; 60:397-406. [PMID: 30682210 DOI: 10.1167/iovs.18-25223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Contrast agents applicable for optical coherence tomography (OCT) imaging are rare. The intrascleral aqueous drainage system would be a potential application for a contrast agent, because the aqueous veins are of small diameter and located deep inside the highly scattering sclera. We tested lipid emulsions (LEs) as candidate OCT contrast agents in vitro and ex vivo, including milk and the anesthetic substance Propofol. Methods Commercial OCT and OCT angiography (OCTA) devices were used. Maximum reflectivity and signal transmission of LE were determined in tube phantoms. Absorption spectra and light scattering was analyzed. The anterior chamber of enucleated porcine eyes was perfused with LEs, and OCTA imaging of the LEs drained via the aqueous outflow tract was performed. Results All LEs showed a significantly higher reflectivity than water (P < 0.001). Higher milk lipid content was positively correlated with maximum reflectivity and negatively with signal transmission. Propofol exhibited the best overall performance. Due to a high degree of signal fluctuation, OCTA could be applied for detection of LE. Compared with blood, the OCTA signal of Propofol was significantly stronger (P = 0.001). As a proof of concept, time-resolved aqueous angiography of porcine eyes was performed. The three-dimensional (3D) structure and dynamics of the aqueous outflow were significantly different from humans. Conclusions LEs induced a strong signal in OCT and OCTA. LE-based OCTA allowed the ability to obtain time-resolved 3D datasets of aqueous outflow. Possible interactions of LE with inner eye's structures need to be further investigated before in vivo application.
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Affiliation(s)
- Hanna M Gottschalk
- Department of Ophthalmology, University Medical Center, Göttingen, Germany
| | | | - Mohammed H Khattab
- Department of Ophthalmology, University Medical Center, Göttingen, Germany
| | | | - Josep Callizo
- Department of Ophthalmology, University Medical Center, Göttingen, Germany
| | - Florian Rehfeldt
- Third Institute of Physics, Biophysics, Georg-August-University, Göttingen, Germany
| | - Roswitha Lubjuhn
- Department of Anaesthesiology, University Medical Center, Göttingen, Germany
| | - Christoph Russmann
- Faculty of Natural Science and Technology, University of Applied Sciences and Arts, Göttingen, Germany.,Molecular Biomarkers Nano-Imaging Laboratory, Brigham and Women's Hospital, and Department of Radiology, Harvard Medical School, Boston, Massachusetts, United States
| | - Hans Hoerauf
- Department of Ophthalmology, University Medical Center, Göttingen, Germany
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Xie X, Akiyama G, Bogarin T, Saraswathy S, Huang AS. Visual Assessment of Aqueous Humor Outflow. Asia Pac J Ophthalmol (Phila) 2019; 8:126-134. [PMID: 30916496 PMCID: PMC7028348 DOI: 10.22608/apo.201911] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
In the past decade, many new pharmacological and surgical treatments have become available to lower intraocular pressure (IOP) for glaucoma. The majority of these options have targeted improving aqueous humor outflow (AHO). At the same time, in addition to new treatments, research advances in AHO assessment have led to the development of new tools to structurally assess AHO pathways and to visualize where aqueous is flowing in the eye. These new imaging modalities have uncovered novel AHO observations that challenge traditional AHO concepts. New behaviors including segmental, pulsatile, and dynamic AHO may have relevance to the disease and the level of therapeutic response for IOP-lowering treatments. By better understanding the regulation of segmental, pulsatile, and dynamic AHO, it may be possible to find new and innovative treatments for glaucoma aiming at these new AHO behaviors.
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Affiliation(s)
- Xiaobin Xie
- From the Eye Hospital of China Academy of Chinese Medical Sciences, Beijing, China; and UCLA Department of Ophthalmology, Doheny Eye Institute, Los Angeles, CA, United States
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Huang AS, Penteado RC, Papoyan V, Voskanyan L, Weinreb RN. Aqueous Angiographic Outflow Improvement after Trabecular Microbypass in Glaucoma Patients. Ophthalmol Glaucoma 2018; 2:11-21. [PMID: 31595267 DOI: 10.1016/j.ogla.2018.11.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Purpose To study changes in aqueous humor outflow (AHO) patterns after trabecular micro-bypass (TMB) in glaucoma patients using intraoperative sequential aqueous angiography. Design Prospective comparative case series. Subjects Fifteen subjects (14 with glaucoma and 1 normal). Methods Sequential aqueous angiography (Spectralis HRA+OCT; Heidelberg Engineering) was performed on fourteen glaucoma patients undergoing routine TMB (iStent Inject; Glaukos Corporation) and cataract surgery and one normal patient undergoing cataract surgery alone. Indocyanine green (ICG) aqueous angiography established initial baseline nasal angiographic AHO patterns. Two TMB stents were placed in regions of baseline low or high angiographic AHO in each eye (n = 2 eyes with enough space to place two stents in both low angiographic regions; n = 8 eyes with two stents both placed in high angiographic regions; n = 4 eyes with enough space to place one stent in a low angiographic region and the other stent in a high angiographic region). Subsequent fluorescein aqueous angiography was utilized to query alterations to angiographic AHO patterns. Main Outcome Measure Angiographic signal and patterns before and after TMB. Results At baseline, all eyes showed segmental angiographic AHO patterns. Focused on the nasal hemisphere of each eye, for each stent TMB in initially low ICG angiographic signal regions showed transient or persistently improved fluorescein angiographic signal (11.2-fold; p = 0.014). TMB in initially high ICG signal regions led to faster development of fluorescein angiographic patterns (3.1-fold; p = 0.02). Conclusion TMB resulted in different patterns of aqueous angiographic AHO improvement whose further understanding may advance basic knowledge of AHO and possibly enhance intraocular pressure reduction after glaucoma surgery in the future.
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Affiliation(s)
- Alex S Huang
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Rafaella C Penteado
- Hamilton Glaucoma Center, Shiley Eye Institute, and Department of Ophthalmology University of California, San Diego, CA, USA
| | - Vahan Papoyan
- Department of Ophthalmology, Yerevan State Medical University, Ophthalmological Center after S.V. Malayan
| | - Lilit Voskanyan
- Department of Ophthalmology, Yerevan State Medical University, Ophthalmological Center after S.V. Malayan
| | - Robert N Weinreb
- Hamilton Glaucoma Center, Shiley Eye Institute, and Department of Ophthalmology University of California, San Diego, CA, USA
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Huang AS, Penteado RC, Saha SK, Do JL, Ngai P, Hu Z, Weinreb RN. Fluorescein Aqueous Angiography in Live Normal Human Eyes. J Glaucoma 2018; 27:957-964. [PMID: 30095604 PMCID: PMC6218293 DOI: 10.1097/ijg.0000000000001042] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate aqueous humor outflow (AHO) in intact eyes of live human subjects during cataract surgery using fluorescein aqueous angiography. METHODS Aqueous angiography was performed in 8 live human subjects (56 to 86 y old; 2 men and 6 women). After anesthesia, fluorescein (2%) was introduced into the eye [either alone or after indocyanine green (ICG; 0.4%)] from a sterile, gravity-driven constant-pressure reservoir. Aqueous angiographic images were obtained with a Spectralis HRA+OCT and FLEX module (Heidelberg Engineering). Using the same device, anterior-segment optical coherence tomography (OCT) and infrared images were also concurrently taken with aqueous angiography. RESULTS Fluorescein aqueous angiography in the live human eye showed segmental AHO patterns. Initial angiographic signal was seen on average by 14.0±3.0 seconds (mean±SE). Using multimodal imaging, angiographically positive signal colocalized with episcleral veins (infrared imaging) and intrascleral lumens (anterior-segment OCT). Sequential aqueous angiography with ICG followed by fluorescein showed similar segmental angiographic patterns. DISCUSSION Fluorescein aqueous angiography in live humans was similar to that reported in nonhuman primates and to ICG aqueous angiography in live humans. As segmental patterns with sequential angiography using ICG followed by fluorescein were similar, these tracers can now be used sequentially, before and after trabecular outflow interventions, to assess their effects on AHO in live human subjects.
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Affiliation(s)
- Alex S Huang
- Department of Ophthalmology, Doheny Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles
| | - Rafaella C Penteado
- Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, CA
| | - Sajib K Saha
- Department of Ophthalmology, Doheny Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles
| | - Jiun L Do
- Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, CA
| | - Philip Ngai
- Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, CA
| | - Zhihong Hu
- Department of Ophthalmology, Doheny Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles
| | - Robert N Weinreb
- Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, CA
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Microcatheter-assisted Trabeculotomy for Primary Congenital Glaucoma After Failed Glaucoma Surgeries. J Glaucoma 2018; 28:1-6. [PMID: 30358646 DOI: 10.1097/ijg.0000000000001116] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the effectiveness of microcatheter-assisted trabeculotomy (MAT) to treat primary congenital glaucoma after failed previous glaucoma surgeries. MATERIALS AND METHODS Retrospective, noncomparative, interventional case series conducted at Beijing Tongren Eye Center, China. Outcome measures were compared between 3 groups: successful and complete (≥330 degrees) MAT; successful and partial (<330 degrees) MAT; or cases converted to traditional trabeculotomy when the Schlemm's canal could not be catheterized >180 degrees. Success was defined as final intraocular pressure ≤21 mm Hg, with (qualified success) or without (complete success) glaucoma medications. RESULTS In total, 74 eyes of 63 consecutive patients were included. MAT was performed in 50 eyes (67.6%). Postoperative intraocular pressure and number of glaucoma drops (17.7±8.6 mm Hg, 0.6±1.2 medications) was significantly less than the preoperative values (35.3±7.2 mm Hg, 2.7±0.8 medications; P<0.001). Cumulative probabilities of qualified and complete success were 84.0% and 80.0% at 3-year follow-up with no difference between complete and partial trabeculotomies. MAT was not successfully performed in 24 eyes (32.4%), requiring conversion to traditional trabeculotomy and associated with greater incidence of previous surgeries (P<0.001), earlier age of disease onset (P=0.024) and worse corneal transparency (P=0.010). Cumulative probabilities of qualified and complete success were 37.0% and 29.2% at 3-year follow-up. CONCLUSIONS Both complete and partial MAT achieved significant pressure reduction in cases of primary congenital glaucoma with previous failed glaucoma surgeries in intermediate term.
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Yoshikawa M, Akagi T, Uji A, Nakanishi H, Kameda T, Suda K, Ikeda HO, Tsujikawa A. Pilot study assessing the structural changes in posttrabecular aqueous humor outflow pathway after trabecular meshwork surgery using swept-source optical coherence tomography. PLoS One 2018; 13:e0199739. [PMID: 29953502 PMCID: PMC6023224 DOI: 10.1371/journal.pone.0199739] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 06/13/2018] [Indexed: 11/19/2022] Open
Abstract
This study evaluated the morphological change in aqueous humor outflow (AHO) pathways using swept-source optical coherence tomography (SS-OCT) volumetric scans in glaucoma patients before and after glaucoma surgery. In this prospective observational case series, 15 eyes (13 patients) with glaucoma were treated with 120-degree Trabectome or 360-degree suture trabeculotomy and followed up for 3 months. B-scan images of the posttrabecular AHO pathway were reconstructed and the pathway areas were evaluated, before and after surgery. Changes in posttrabecular AHO pathway were qualitatively classified as “increased”, “non-significant change”, and “decreased” on reconstructed B-scan images. Quantitative measurements of the posttrabecular AHO pathway areas were performed pre- and postoperatively. Factors associated with both qualitative and quantitative changes in AHO pathway were investigated. From 30 regions (15 nasal and 15 temporal regions) in the 15 eyes, AHO pathways were analyzable in 20 regions pre- and postoperatively. Qualitative assessments of the pathway changes were “increased” in 8 regions, “non-significant change” in 9 regions, and “decreased” in 3 regions. Quantitative assessments of the average pathway area did not change significantly (from 3155±1633 pixels preoperatively to 3212±1684 pixels postoperatively, P = 0.50). All parameters relating to intraocular pressure changes or the surgical location were not associated with postoperative AHO pathway change. The intrascleral AHO pathway could be well visualized in glaucoma patients pre- and postoperatively using swept-source optical coherence tomography. However, structural changes in the AHO pathway assessed by SS-OCT were not significant after trabecular-targeted glaucoma surgery. Functional assessments of AHO are needed in future studies.
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Affiliation(s)
- Munemitsu Yoshikawa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tadamichi Akagi
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
- * E-mail:
| | - Akihito Uji
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hideo Nakanishi
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takanori Kameda
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kenji Suda
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hanako Ohashi Ikeda
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akitaka Tsujikawa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
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Huang AS, Francis BA, Weinreb RN. Structural and functional imaging of aqueous humour outflow: a review. Clin Exp Ophthalmol 2017; 46:158-168. [PMID: 28898516 DOI: 10.1111/ceo.13064] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 09/06/2017] [Indexed: 01/15/2023]
Abstract
Maintaining healthy aqueous humour outflow (AHO) is important for intraocular cellular health and stable vision. Impairment of AHO can lead to increased intraocular pressure, optic nerve damage and concomitant glaucoma. An improved understanding of AHO will lead to improved glaucoma surgeries that enhance native AHO as well as facilitate the development of AHO-targeted pharmaceuticals. Recent AHO imaging has evolved to live human assessment and has focused on the structural evaluation of AHO pathways and the functional documentation of fluid flow. Structural AHO evaluation is predominantly driven by optical coherence tomography, and functional evaluation of flow is performed using various methods, including aqueous angiography. Advances in structural and functional evaluation of AHO are reviewed with discussion of strengths, weaknesses and potential future directions.
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Affiliation(s)
- Alex S Huang
- Doheny Eye Institute, Los Angeles, California, USA.,Doheny Eye Centers, Department of Ophthalmology, David Geffen School of Medicine at University of California, Los Angeles, California, USA
| | - Brian A Francis
- Doheny Eye Institute, Los Angeles, California, USA.,Doheny Eye Centers, Department of Ophthalmology, David Geffen School of Medicine at University of California, Los Angeles, California, USA
| | - Robert N Weinreb
- Shiley Eye Institute and Hamilton Glaucoma Center, Department of Ophthalmology, University of California, San Diego, California, USA
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Adjunctive Imaging for Canal-based Glaucoma Surgery. Int Ophthalmol Clin 2017; 57:73-84. [PMID: 28885248 DOI: 10.1097/iio.0000000000000199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Xin C, Chen X, Li M, Shi Y, Wang H, Wang R, Wang N. Imaging collector channel entrance with a new intraocular micro-probe swept-source optical coherence tomography. Acta Ophthalmol 2017; 95:602-607. [PMID: 28440591 DOI: 10.1111/aos.13415] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 01/13/2017] [Indexed: 01/09/2023]
Abstract
PURPOSE To describe the use of a newly developed side-viewing catheter probe to provide the cross-sectional images of collector channel entrance (CCE), achieved by swept-source optical coherence tomography (SS-OCT). METHODS A side-viewing SS-OCT catheter probe was developed that has a core probe diameter of 0.15 mm and an outer diameter of 0.25 mm, for the purpose of imaging CCEs within eye globe. Cadaver eyes harvested from swine and human were used to demonstrate its feasibility. For porcine eyes, the probe imaged the CCE by accessing the region of the aqueous plexus (AP) as well as along the inner wall (IW) of the trabecular meshwork (TM). For human eyes, the CCE images were captured by placing the probe within the lumen of the Schlemm's canal (SC) and along its IW. RESULTS With the optical coherence tomography (OCT) catheter probe, the CCE is well delineated as optically empty areas within the highly scattering sclera. In porcine eyes, images captured in the region of the AP demonstrate a large cavity with delicate tissue strands around the probe. The CCE can be identified at the outer margin of the AP. When imaged along the IW, the TM is discernable but difficult to be distinguished from the AP. In the human limbal regions, when placed within the lumen of the SC, the catheter probe fully occupies the potential space. TM is highly compact. The CCE can be identified at the outer wall of the SC. When imaged along the IW of TM, the SC and CCE can be identified. CONCLUSION The intraocular SS-OCT catheter probe is feasible to provide the CCE images, indicating useful clinical applications to assist glaucoma surgery.
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Affiliation(s)
- Chen Xin
- Department of Ophthalmology; Beijing Anzhen Hospital; Capital Medical University; Beijing China
| | - Xiaoya Chen
- Department of Ophthalmology; Xuzhou 1st Hospital; Jiangsu China
| | - Meng Li
- Department of Ophthalmology; Beijing Tongren Hospital; Capital Medical University; Beijing China
| | - Yan Shi
- Department of Ophthalmology; Beijing Tongren Hospital; Capital Medical University; Beijing China
| | - Huaizhou Wang
- Department of Ophthalmology; Beijing Tongren Hospital; Capital Medical University; Beijing China
| | - Ruikang Wang
- Department of Bioengineering; University of Washington; Seattle Washington USA
- Department of Ophthalmology; University of Washington; Seattle Washington USA
| | - Ningli Wang
- Department of Ophthalmology; Beijing Tongren Hospital; Capital Medical University; Beijing China
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Huang AS, Belghith A, Dastiridou A, Chopra V, Zangwill LM, Weinreb RN. Automated circumferential construction of first-order aqueous humor outflow pathways using spectral-domain optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:66010. [PMID: 28617922 PMCID: PMC5472236 DOI: 10.1117/1.jbo.22.6.066010] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 05/30/2017] [Indexed: 05/28/2023]
Abstract
The purpose was to create a three-dimensional (3-D) model of circumferential aqueous humor outflow (AHO) in a living human eye with an automated detection algorithm for Schlemm’s canal (SC) and first-order collector channels (CC) applied to spectral-domain optical coherence tomography (SD-OCT). Anterior segment SD-OCT scans from a subject were acquired circumferentially around the limbus. A Bayesian Ridge method was used to approximate the location of the SC on infrared confocal laser scanning ophthalmoscopic images with a cross multiplication tool developed to initiate SC/CC detection automated through a fuzzy hidden Markov Chain approach. Automatic segmentation of SC and initial CC’s was manually confirmed by two masked graders. Outflow pathways detected by the segmentation algorithm were reconstructed into a 3-D representation of AHO. Overall, only <1% of images (5114 total B-scans) were ungradable. Automatic segmentation algorithm performed well with SC detection 98.3% of the time and <0.1% false positive detection compared to expert grader consensus. CC was detected 84.2% of the time with 1.4% false positive detection. 3-D representation of AHO pathways demonstrated variably thicker and thinner SC with some clear CC roots. Circumferential (360 deg), automated, and validated AHO detection of angle structures in the living human eye with reconstruction was possible.
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Affiliation(s)
- Alex S. Huang
- Doheny Eye Institute, Los Angeles, California, United States
- Doheny Eye Centers, Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Akram Belghith
- Shiley Eye Institute and Hamilton Glaucoma Center, Department of Ophthalmology University of California, San Diego, California, United States
| | - Anna Dastiridou
- Doheny Eye Centers, Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Vikas Chopra
- Doheny Eye Institute, Los Angeles, California, United States
- Doheny Eye Centers, Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Linda M. Zangwill
- Shiley Eye Institute and Hamilton Glaucoma Center, Department of Ophthalmology University of California, San Diego, California, United States
| | - Robert N. Weinreb
- Shiley Eye Institute and Hamilton Glaucoma Center, Department of Ophthalmology University of California, San Diego, California, United States
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Huang AS, Camp A, Xu BY, Penteado RC, Weinreb RN. Aqueous Angiography: Aqueous Humor Outflow Imaging in Live Human Subjects. Ophthalmology 2017; 124:1249-1251. [PMID: 28461013 DOI: 10.1016/j.ophtha.2017.03.058] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 03/29/2017] [Accepted: 03/30/2017] [Indexed: 10/19/2022] Open
Affiliation(s)
- Alex S Huang
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California.
| | - Andrew Camp
- Hamilton Glaucoma Center, Shiley Eye Institute and Department of Ophthalmology, University of California, San Diego, California
| | - Benjamin Y Xu
- Hamilton Glaucoma Center, Shiley Eye Institute and Department of Ophthalmology, University of California, San Diego, California
| | - Rafaella C Penteado
- Hamilton Glaucoma Center, Shiley Eye Institute and Department of Ophthalmology, University of California, San Diego, California
| | - Robert N Weinreb
- Hamilton Glaucoma Center, Shiley Eye Institute and Department of Ophthalmology, University of California, San Diego, California
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Huang AS, Li M, Yang D, Wang H, Wang N, Weinreb RN. Aqueous Angiography in Living Nonhuman Primates Shows Segmental, Pulsatile, and Dynamic Angiographic Aqueous Humor Outflow. Ophthalmology 2017; 124:793-803. [PMID: 28237425 DOI: 10.1016/j.ophtha.2017.01.030] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 01/18/2017] [Accepted: 01/19/2017] [Indexed: 11/18/2022] Open
Abstract
PURPOSE To evaluate the feasibility of safely performing aqueous angiography in intact eyes of living nonhuman primates (NHPs) for evaluating aqueous humor outflow and segmental patterns. DESIGN Cross-sectional, observational study. SUBJECTS Six nonhuman primates. METHODS Aqueous angiography was performed in 6 nonhuman primates. After anesthesia, an anterior chamber (AC) maintainer was placed through a temporal 1-mm side-port wound. Indocyanine green (ICG; 0.4%) or 2.5% fluorescein was introduced (individually or in sequence) into the eye with a gravity-driven constant-pressure system. Aqueous angiography images were obtained with a Spectralis HRA+OCT (Heidelberg Engineering GmbH, Heidelberg, Germany) suspended over the NHP eye using a custom-designed surgical boom arm. Concurrent anterior segment optical coherence tomography (OCT) was performed on distally angiographically positive and negative regions. MAIN OUTCOME MEASURES Angiographic patterns described by location, time-course, choice of tracer, and anterior-segment OCT. RESULTS Aqueous angiography in the living NHP eye demonstrated mostly stable angiographic patterns. With multimodal imaging, angiographically positive signal co-localized with episcleral veins as identified by infrared imaging and intrascleral lumens, as demonstrated by anterior segment OCT. Sequential aqueous angiography in individual eyes with ICG followed by fluorescein showed similar angiographic patterns. A pulsatile nature of aqueous angiographic outflow was sometimes observed. Aqueous angiographic patterns could also dynamically change. In some instances, positive angiographic flow suddenly arose in regions previously without an angiographic signal. Alternatively, an angiographic signal could suddenly disappear from regions in which an angiographic signal was initially documented. CONCLUSIONS Aqueous angiography in living NHPs demonstrated segmental and pulsatile patterns with a newly described ability to dynamically shift. These characteristics further the understanding of live aqueous humor outflow biology and may be useful in improving glaucoma surgeries aimed at trabecular meshwork bypass.
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Affiliation(s)
- Alex S Huang
- Doheny Eye Institute, Los Angeles, California, and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California.
| | - Meng Li
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Diya Yang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Huaizhou Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Ningli Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
| | - Robert N Weinreb
- Hamilton Glaucoma Center and Shiley Eye Institute, University of California, San Diego, California
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