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Demographic, clinical and tomographic characteristics of pellucid marginal degeneration patients in South Egyptian population. Int Ophthalmol 2022; 42:3237-3242. [PMID: 36001208 PMCID: PMC9509300 DOI: 10.1007/s10792-022-02326-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 04/18/2022] [Indexed: 12/04/2022]
Abstract
Purpose To retrospectively evaluate the demographic, clinical, and tomographic characteristics of pellucid marginal degeneration (PMD) patients in South Egypt. Methods This study was retrospective cross-sectional, including all patients who attended and sought refractive surgery at Sohag Center for Corneal and Refractive Surgeries, Sohag, South Egypt, between October 2016 and October 2020, and had a diagnosis of PMD. It included cases of PMD at different stages. Cases with PMD were diagnosed by the two authors (experienced in corneal refractive surgery), combining both slit-lamp biomicroscopy findings and corneal tomography. Results Out of the 2534 patients attending the Sohag Center for Corneal and Refractive Surgeries (between October 2016 and May 2020) seeking correction of their refractive errors, 24 patients were found to fit in the diagnosis of PMD. Forty-three eyes of the 24 patients were diagnosed with PMD. The topographic patterns ranged from horizontal bow tie (against the rule astigmatism) being the least presenting, followed by crab claw, then butterfly pattern. Conclusion PMD is a separate entity of the ectatic corneal spectrum that can easily be misinterpreted as Keratoconus. Topographic and tomographic patterns cannot solely diagnose PMD as they should be enforced by slit-lamp findings.
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Narang P, Holladay J, Agarwal A, Gracy H, Kumar DA, Sivagnanam S. Pinhole Pupilloplasty for Higher Order Aberrations: Assessment of Visual Quality and Depth of Focus. J Refract Surg 2021; 36:812-819. [PMID: 33295993 DOI: 10.3928/1081597x-20201008-01] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 09/10/2020] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate visual quality and depth of focus under photopic and mesopic light conditions of patients treated with pinhole pupilloplasty (PPP) for corneal higher order aberrations. METHODS This was a prospective, noncomparative, interventional series and PPP was performed with a single-pass four-throw procedure in 14 eyes of 14 patients. After PPP, patients were analyzed with the Clinical Trial Suite machine (M & S Technologies, Inc) that offers a standardized method of recording visual quality. The luminance levels of 85 and 3 cd/m2 were set for photopic and mesopic lighting conditions, respectively, and uncorrected and corrected distance visual acuity were recorded for distance (4 m), intermediate (66 cm), and near (44 cm). Low contrast acuity (LCA) at 10% and mesopic contrast sensitivity function (CSF) with glare on and off at four spatial frequencies of 1.5, 3, 6, and 12 cycles per degree (cpd) and defocus curve were assessed. RESULTS Under photopic and mesopic conditions, a significant difference was observed postoperatively in uncorrected and corrected distance visual acuity for distance, intermediate, and near. The defocus curve demonstrated extended depth of focus that ranged from +1.50 to -2.50 diopters and LCA at 10% demonstrated significant improvement for all cases. For mesopic CSF, a significant improvement was noted at spatial frequencies of 3 and 6 cpd with glare on. With glare off, an improvement was seen at spatial frequencies of 1.5, 3, and 6 cpd, but not at 12 cpd. CONCLUSIONS Early results demonstrate that PPP provides improved visual quality and extended depth of focus and can be a useful option in cases with higher order aberrations. [J Refract Surg. 2020;36(12):812-819.].
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Long-term safety of in-the-bag implantation of a supplementary intraocular pinhole. J Cataract Refract Surg 2020; 46:888-892. [DOI: 10.1097/j.jcrs.0000000000000163] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sakellaris D, Balidis M, Gorou O, Szentmary N, Alexoudis A, Grieshaber MC, Sagri D, Scholl H, Gatzioufas Z. Intracorneal Ring Segment Implantation in the Management of Keratoconus: An Evidence-Based Approach. Ophthalmol Ther 2019; 8:5-14. [PMID: 31605316 PMCID: PMC6789055 DOI: 10.1007/s40123-019-00211-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Indexed: 01/19/2023] Open
Abstract
Intracorneal ring segment (ICRS) implantation represents a modern, minimally invasive, surgical option for visual improvement in patients with keratoconus. ICRS modify the corneal geometry in a manner that enhances its refractive properties and thereby, they improve visual acuity. It is well-documented that implantation of ICRS decreases the keratometric readings, spherical equivalent and cylinder, reduces high-order aberrations and improves uncorrected distance visual acuity (UDVA) and best-corrected distance visual acuity (BCDVA) in patients with keratoconus. Success rate after ICRS implantation is high, depending on appropriate patient selection and adherence to suitable implantation nomograms, and most important, the overall complication rate is very low. This review is summarizing current indications/contra-indications for ICRS implantation, implantation techniques, clinical outcomes and potential complications, shedding light on myths and realities related to this innovative surgical option.
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Affiliation(s)
| | | | - Olga Gorou
- Ophthalmica Institute, Thessaloniki, Greece
| | - Nora Szentmary
- Department of Ophthalmology, University Clinic Saarland, Homburg, Saarland, Germany
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Antonios Alexoudis
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | | | | | - Hendrik Scholl
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | - Zisis Gatzioufas
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland.
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Trindade BL, Trindade FC, Trindade CL. Intraocular pinhole implantation for irregular astigmatism after planned and unplanned posterior capsule opening during cataract surgery. J Cataract Refract Surg 2019; 45:372-377. [DOI: 10.1016/j.jcrs.2018.11.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 11/13/2018] [Accepted: 11/17/2018] [Indexed: 10/27/2022]
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Lohchab M, Prakash G, Arora T, Maharana P, Jhanji V, Sharma N, Vajpayee RB. Surgical management of peripheral corneal thinning disorders. Surv Ophthalmol 2018; 64:67-78. [PMID: 29886126 DOI: 10.1016/j.survophthal.2018.06.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 06/01/2018] [Accepted: 06/04/2018] [Indexed: 10/14/2022]
Abstract
The peripheral corneal thinning disorders are associated with degenerative, autoimmune, or infective causes. Corneal thinning can subsequently affect the visual acuity either by inducing severe astigmatism or by progressive involvement of the central cornea. In addition to this, the integrity of the eye is at risk. Medical management is necessary to address the underlying inflammatory or infectious causes; however, most of the cases require surgical intervention for tectonic support or for visual rehabilitation in patients with severe astigmatism. Preoperative investigations help in mapping the corneal curvature and thickness, thereby facilitating planning of treatment. Routine corneal transplantation techniques do not yield good results in peripheral corneal thinning disorders. Various surgical modifications have been described to manage these challenging cases. We review the available literature on causes and management of peripheral corneal thinning disorders.
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Affiliation(s)
- Monica Lohchab
- Cornea and Phacorefractive services, Guru Nanak Eye Centre, Maulana Azad Medical College, New Delhi, India
| | - Gaurav Prakash
- NMC eye care, New Medical Centre Specialty Hospital, Abu Dhabi, UAE
| | - Tarun Arora
- Eye Care Centre, Princess Margaret Hospital, Nassau, New Providence, Bahamas
| | - Prafulla Maharana
- RP Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Vishal Jhanji
- University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Namrata Sharma
- RP Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Rasik B Vajpayee
- Vision Eye Institute, Melbourne, Australia; Royal Victorian Eye and Ear Hospital, Melbourne, Australia; North West Academic Centre, University of Melbourne, Australia.
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Refractive and Corneal Aberrometric Changes After Crescentic Lamellar Wedge Resection in Pellucid Marginal Degeneration. Eye Contact Lens 2017; 44 Suppl 2:S76-S80. [PMID: 28737665 DOI: 10.1097/icl.0000000000000409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the effectiveness of crescentic corneal lamellar wedge resection for the treatment of pellucid marginal degeneration (PMD) in improving refractive, visual, and corneal aberrometry. METHODS The study included 10 eyes of 10 patients who had undergone corneal lamellar wedge resection for PMD. Pellucid marginal degeneration was diagnosed based on the clinical signs and corneal topography. The corneal aberrometry was evaluated with Sirius corneal topography. RESULTS The mean follow-up period was 14.1 months (range, 9-24 months). Uncorrected visual acuity was improved in nine eyes and remained unchanged in 1 case, whereas best-corrected visual acuity was improved in all eyes postoperatively. By vector analysis, the overall mean astigmatic drift at the last visit was calculated to be 13.0±6.3 diopters (D). At last visit, significant reductions were found for all aberrometric measurements. However, the differences were not significant for the measurements of trefoil (P=0.189). CONCLUSIONS Corneal lamellar wedge resection is a favorable surgical option for management of PMD, allowing for improved visual acuity, keratometric cylinder, and corneal aberrations.
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Affiliation(s)
- Davin Johnson
- Department of Ophthalmology, CHUM-Notre Dame Hospital, Montreal, Canada
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Reshaping procedures for the surgical management of corneal ectasia. J Cataract Refract Surg 2015; 41:842-72. [PMID: 25840308 DOI: 10.1016/j.jcrs.2015.03.010] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 07/15/2014] [Accepted: 07/23/2014] [Indexed: 12/31/2022]
Abstract
UNLABELLED Corneal ectasia is a progressive, degenerative, and noninflammatory thinning disorder of the cornea. Recently developed corneal reshaping techniques have expanded the treatment armamentarium available to the corneal specialist by offering effective nontransplant options. This review summarizes the current evidence base for corneal collagen crosslinking, topography-guided photorefractive keratectomy, and intrastromal corneal ring segment implantation for the treatment of corneal ectasia by analyzing the data published between the years 2000 and 2014. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Moshirfar M, Edmonds JN, Behunin NL, Christiansen SM. Current Options in the Management of Pellucid Marginal Degeneration. J Refract Surg 2014; 30:474-85. [DOI: 10.3928/1081597x-20140429-02] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 03/11/2014] [Indexed: 11/20/2022]
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Labiris G, Giarmoukakis A, Sideroudi H, Song X, Kozobolis V, Seitz B, Gatzioufas Z. Diagnostic capacity of biomechanical indices from a dynamic bidirectional applanation device in pellucid marginal degeneration. J Cataract Refract Surg 2014; 40:1006-12. [PMID: 24774010 DOI: 10.1016/j.jcrs.2014.03.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 03/06/2014] [Accepted: 03/07/2014] [Indexed: 10/25/2022]
Abstract
PURPOSE To evaluate the diagnostic capacity of the keratoconus match index (KMI) and keratoconus match probability (KMP) classification from a dynamic bidirectional applanation device (Ocular Response Analyzer) in eyes with pellucid marginal degeneration (PMD). SETTING Department of Ophthalmology, University Clinics Saarland, Homburg, Germany. DESIGN Cross-sectional study. METHODS Pellucid marginal degeneration eligibility was confirmed by inferior peripheral thinning, corneal protrusion, and irregular astigmatism. The KMI and KMP parameters in PMD eyes (study group) were compared with those in normal eyes (control group). The KMI's overall predictive accuracy was assessed operating characteristic (ROC) curves. The relationship between KMI and corneal hysteresis (CH), the corneal resistance factor (CRF), and a series of Scheimpflug camera indices was evaluated with Spearman analysis (r). RESULTS The mean KMI in the study group (40 eyes) and control group (40 eyes) was 0.34 ± 0.43 (SD) and 0.95 ± 0.30, respectively (P<.001). The KMI correlated significantly with the CH, CRF, and most Scheimpflug camera indices. Regression analysis indicated that the index of height decentration (r = -0.877, P<.001) was the primary determinant of the KMI. Moreover, the KMP index identified 50.0%, 29.16%, and 20.83% of PMD eyes as ectatic, suspect for ectasia, and normal, respectively. The ROC curve analysis of the KMI parameter indicated a predictive accuracy of 94.8% (cutoff point 0.626; sensitivity 85.71%; specificity 90.1%). CONCLUSIONS The KMI seems to be a promising diagnostic index for PMD. In contrast, the KMP index identified a significant percentage of topographically defined PMD eyes as normal, limiting its diagnostic value in PMD. FINANCIAL DISCLOSURES No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Georgios Labiris
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece.
| | - Athanassios Giarmoukakis
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece
| | - Haris Sideroudi
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece
| | - Xuefei Song
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece
| | - Vassilios Kozobolis
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece
| | - Berthold Seitz
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece
| | - Zisis Gatzioufas
- From the Department of Ophthalmology (Labiris, Song, Seitz, Gatzioufas), University Medical Center of Saarland UKS, Homburg/Saar, Germany; the Eye Institute of Thrace (Labiris, Giarmoukakis, Sideroudi, Kozobolis,), Alexandroupolis, Greece
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Camoriano GD, Aman-Ullah M, Purba MK, Sun J, Gimbel HV. Toric collagen copolymer phakic intraocular lens to correct myopic astigmatism in eyes with pellucid marginal degeneration. J Cataract Refract Surg 2012; 38:256-61. [DOI: 10.1016/j.jcrs.2011.08.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 08/12/2011] [Accepted: 08/14/2011] [Indexed: 10/14/2022]
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Pellucid corneal marginal degeneration: A review. Cont Lens Anterior Eye 2011; 34:56-63. [DOI: 10.1016/j.clae.2010.11.007] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Revised: 11/11/2010] [Accepted: 11/29/2010] [Indexed: 11/21/2022]
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Alio JL, Piñero DP, Daxer A. Clinical outcomes after complete ring implantation in corneal ectasia using the femtosecond technology: a pilot study. Ophthalmology 2011; 118:1282-90. [PMID: 21440940 DOI: 10.1016/j.ophtha.2010.12.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 08/18/2010] [Accepted: 12/12/2010] [Indexed: 10/18/2022] Open
Abstract
PURPOSE To evaluate the clinical outcomes after implantation of the MyoRing (DIOPTEX GmBH, Linz, Austria) by means of femtosecond laser technology in eyes with corneal ectasia. DESIGN Retrospective, consecutive, nonrandomized, case series. PARTICIPANTS A total of 12 eyes of 11 patients with ages ranging from 17 to 50 years were included. All cases were diagnosed with corneal ectasia according to the standard criteria: 1 case of post-LASIK ectasia and 11 cases of keratoconus. All cases presented with reduced best spectacle-corrected visual acuity, contact lens intolerance or discomfort, and central corneal thickness of more than 350 μm. METHODS MyoRing inserts of 280 μm in thickness and 5 mm in diameter were implanted in all cases into an intrastromal corneal pocket created by means of femtosecond technology. Visual, refractive, corneal topography, and pachymetric changes were evaluated during a 6-month follow-up. In addition, corneal biomechanical changes were evaluated by means of the Ocular Response Analyzer (Reichert, Buffalo, NY). MAIN OUTCOME MEASURES Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, keratometry, corneal asphericity, corneal higher-order aberrations, pachymetry, corneal hysteresis (CH), and corneal resistance factor (CRF). RESULTS A significant improvement in UDVA was observed 1 week after surgery (P=0.001), which was consistent with the significant reduction in sphere (P=0.002) and cylinder (P=0.004). No significant changes were detected in these parameters afterward (P ≥ 0.263). Furthermore, a significant corneal flattening of a mean value of 8.03 diopters (D) was found (P=0.005). This keratometric change was correlated with the magnitude of corneal coma-like aberrations (r=0.830, P=0.003) and the CRF (r=-0.782, P=0.008). In regard to aberrometry, a statistically significant increase in primary spherical aberration was found 1 month after surgery (P=0.001). In addition, a significant reduction in higher-order corneal aberrations was found 3 to 6 months after surgery (P=0.027). Significant corneal thickening was also observed postoperatively in the central, nasal, and temporal areas (P ≤ 0.013). No statistically significant changes were detected (P ≥ 0.176) in corneal biomechanics. Explantation was performed in a very advanced keratoconus because of the extremely poor visual outcome. CONCLUSIONS MyoRing implantation using femtosecond technology in keratoconus allows successful corneal modeling, although the use of large diameters is advisable.
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Affiliation(s)
- Jorge L Alio
- Vissum/Instituto Oftalmológico de Alicante, Spain.
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Renesto ADC, Campos M. Intrastromal Corneal Ring Segments. Cornea 2011. [DOI: 10.1016/b978-0-323-06387-6.00176-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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November consultation #2. J Cataract Refract Surg 2010. [DOI: 10.1016/j.jcrs.2010.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Kubaloglu A, Sari ES, Cinar Y, Cingu K, Koytak A, Coşkun E, Özertürk Y. Comparison of mechanical and femtosecond laser tunnel creation for intrastromal corneal ring segment implantation in keratoconus. J Cataract Refract Surg 2010; 36:1556-61. [DOI: 10.1016/j.jcrs.2010.04.028] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 04/01/2010] [Accepted: 04/02/2010] [Indexed: 10/19/2022]
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Implantation of new intracorneal ring segments after segment explantation for unsuccessful outcomes in eyes with keratoconus. J Cataract Refract Surg 2010; 36:1303-10. [DOI: 10.1016/j.jcrs.2010.02.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 02/02/2010] [Accepted: 02/10/2010] [Indexed: 10/19/2022]
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Piñero DP, Alio JL. Intracorneal ring segments in ectatic corneal disease - a review. Clin Exp Ophthalmol 2010; 38:154-67. [DOI: 10.1111/j.1442-9071.2010.02197.x] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Piñero DP, Alió JL, El Kady B, Pascual I. Corneal aberrometric and refractive performance of 2 intrastromal corneal ring segment models in early and moderate ectatic disease. J Cataract Refract Surg 2010; 36:102-9. [DOI: 10.1016/j.jcrs.2009.07.030] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 07/16/2009] [Accepted: 07/22/2009] [Indexed: 11/27/2022]
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Piñero DP, Alio JL, Morbelli H, Uceda-Montanes A, Kady BE, Coskunseven E, Pascual I. Refractive and Corneal Aberrometric Changes after Intracorneal Ring Implantation in Corneas with Pellucid Marginal Degeneration. Ophthalmology 2009; 116:1656-64. [DOI: 10.1016/j.ophtha.2009.06.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 05/26/2009] [Accepted: 06/02/2009] [Indexed: 11/25/2022] Open
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Kymionis GD, Bouzoukis DI, Haft P, Siganos CS, Yoo S. Intrastromal corneal ring segments for the treatment of irregular astigmatism. EXPERT REVIEW OF OPHTHALMOLOGY 2008. [DOI: 10.1586/17469899.3.1.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Ertan A, Colin J. Intracorneal rings for keratoconus and keratectasia. J Cataract Refract Surg 2007; 33:1303-14. [PMID: 17586391 DOI: 10.1016/j.jcrs.2007.02.048] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Accepted: 02/15/2007] [Indexed: 10/23/2022]
Abstract
Intrastromal corneal ring segments were designed to achieve refractive adjustment by flattening the cornea. Recently, they have been used to reshape keratoconic corneas to improve uncorrected visual acuity, best corrected visual acuity, and contact lens tolerance and to delay or prevent the need for keratoplasty. Intracorneal ring segments have several distinct and important advantages. New thicknesses and different ring sizes and the use of femtosecond lasers to dissect channels inside the cornea will likely improve the surgical outcomes. This article reviews the latest data published or presented at meetings on the correction of keratoconus and keratectasia by intracorneal ring segments.
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Affiliation(s)
- Aylin Ertan
- Kudret Eye Hospital, Ankara, Turkey, and the Bordeaux University, Bordeaux, France.
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Ertan A. Differentiating Keratoconus and Pellucid Marginal Degeneration/Reply. J Refract Surg 2007; 23:221-2; author reply 222. [PMID: 17385284 DOI: 10.3928/1081-597x-20070301-01] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Ertan A, Bahadir M. Management of Superior Pellucid Marginal Degeneration With a Single Intracorneal Ring Segment Using Femtosecond Laser. J Refract Surg 2007; 23:205-8. [PMID: 17326362 DOI: 10.3928/1081-597x-20070201-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE A 26-year-old man with superior pellucid marginal corneal degeneration associated with poor visual acuity due to irregular astigmatism was treated with single-segment intracorneal ring insertion. METHODS Preoperatively the patient's uncorrected visual acuity (UCVA) was 0.05, best spectacle-corrected visual acuity (BSCVA) was 0.15, and manifest refraction was -4.50 x 85 in the left eye. The flattest meridian (K1) measured was 38.50 x 90 and the steepest meridian (K2) was 51.10 x 30. RESULTS Three months postoperatively, UCVA was 0.15, BSCVA was 0.4, and manifest refraction was -2.50 x 90. CONCLUSIONS The use of single Intacs with femtosecond laser to treat superior pellucid marginal corneal degeneration improved visual acuity.
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Ertan A, Bahadir M. Intrastromal ring segment insertion using a femtosecond laser to correct pellucid marginal corneal degeneration. J Cataract Refract Surg 2006; 32:1710-6. [PMID: 17010872 DOI: 10.1016/j.jcrs.2006.06.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Accepted: 06/03/2006] [Indexed: 11/16/2022]
Abstract
PURPOSE To assess the outcomes of intrastromal ring segment (Intacs, Addition Technology) implantation using a femtosecond laser in patients with pellucid marginal corneal degeneration. SETTING Kudret Eye Hospital, Ankara, Turkey. METHODS In this retrospective noncomparative case series, 9 eyes of 6 patients with pellucid marginal corneal degeneration had implantation of Intacs segments by a femtosecond laser technique. Preoperative and postoperative evaluations included slitlamp examination, uncorrected (UCVA) and best corrected (BCVA) visual acuities, and keratometry by a Pentacam Scheimpflug camera (Oculus Opticgerate GmbH). All parameters were reviewed within 6 months. RESULTS Intacs were successfully implanted in all eyes. The UCVA significantly improved from preoperatively to 6 months after Intacs implantation (mean 0.18 +/- 0.24 [SD] and 0.53 +/- 0.23, respectively). The mean difference between the preoperative and postoperative UCVA was 3.5 +/- 1.6 lines (P = .008). The BCVA also significantly improved from preoperatively to 6 months after implantation (mean 0.63 +/- 0.26 and 0.85 +/- 0.18 at 6 months, respectively). The Snellen BCVA was 1.0 in 5 eyes postoperatively. The mean difference between preoperative and postoperative BCVA was 2.3 +/- 51 lines (P = .011). The mean preoperative spherical refraction decreased from -3.86 +/- 2.91 diopters (D) to -2.77 +/- 1.43D (P = .091) and the mean cylindrical refraction, from -2.41 +/- 2.27 D to -0.94 +/- 1.07 D (P = .046). The mean central corneal curvature decreased from 48.20 +/- 4.19 D preoperatively to 46.90 +/- 5.00 D (P = .008) at 6 months and the mean posterior elevation, from 53.88 +/- 21.72 microm to 32.55 +/- 11.23 microm (P = .008). CONCLUSION Intacs insertion using a femtosecond laser was safe and efficient in the correction of pellucid marginal corneal degeneration.
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Abstract
BACKGROUND INTACS are two, arc like, PMMA segments which were designed to be surgically inserted into the deep corneal stroma to flatten the central cornea. Their original application was for the refractive correction of mild myopia (−1 to −3D). However, because of the superior accuracy and familiarity with the excimer laser by refractive surgeons, they are rarely used for this indication, except in patients with forme fruste keratoconus or extremely thin corneas with less than 3D of Myopia (1,2). Dr. Joseph Colin in France first conceived of the concept of using INTACS to treat patients with keratoconus and published his first report on the safety and efficacy for this indication in 2001(3). At 1 year, all 10 patients he operated became contact lens tolerant and demonstrated an improvement in both uncorrected and best-corrected acuity (4). Since his pioneering work, corneal surgeons throughout the word have adopted this technology to treat patients with mild to moderate keratoconus who are contact lens intolerant and/or who desire a modest improvement in uncorrected and best-corrected visual acuity (5-14). In the United States 0.25mm, 0.275mm, 0.30mm, 0.325mm and 0.35mm segments are available for use. They are approved in the United States by the FDA under an Human Devise Exemption for compassionate therapeutic use. Outside of the United States .40mm and 0.45mm sized segments are also available. Competitive devices the Ferrara ring and the Keraring are also sold and marketed outside of the United States since they do not have FDA approval in the USA. The main difference between these two devices is that with INTACS the optical zone is approximately 7mm while the Ferrara and Kerarings have an optical zone of the order of 4.5 to 5mm. Recently Intacs SK was introduced outside of the United States. They have an optical zone of 6 mm and have a round design to minimize glare. They may be used to correct larger myopic and astigmatic refractive errors than INTACS because of their design and closer proximity to the visual axis(15)
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Affiliation(s)
- Yaron S Rabinowitz
- Cornea Genetic Eye Institute, Cedars-Sinai Medical Center, Mark Goodson Building, 444 S. San Vincente 704, Los Angeles, CA 90048, USA
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