1
|
Omar Yousif M, Elkitkat RS, Hamza MN, Abdelsadek Alaarag N. Application of a Revised Tissue Saving Protocol for Combined Topography-Guided Photorefractive Keratectomy and Cross-Linking in a Cohort Having Pellucid Marginal Degeneration. Clin Ophthalmol 2024; 18:303-311. [PMID: 38317793 PMCID: PMC10840534 DOI: 10.2147/opth.s449766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 01/18/2024] [Indexed: 02/07/2024] Open
Abstract
Purpose To evaluate the efficiency, safety, and stability of a revised tissue-saving treatment protocol in a cohort having pellucid marginal degeneration (PMD). Methods A retrospective cohort study was conducted on patients with PMD and no previous treatments. A revised protocol of topo-guided photorefractive keratectomy to be followed by customized phototherapeutic keratectomy and then corneal crosslinking was evaluated by comparing the pre and postoperative outcomes regarding visual (subjective refraction) and topographic (using data from Sirius CSO topography software) outcomes. Results There were both statistically significant and clinically relevant improvements in the postoperative parameters, where each of the unaided and corrected visual acuity, spherical equivalent, refractive cylinder, K readings, topographic cylinder, inferior minus superior difference at the 2- and 4- mm diameters, coma aberration, and higher order aberrations were significantly better postoperatively (all p values were less than 0.01, except for maximum k readings where the p-value was 0.017). The safety and efficacy indices for the surgical procedure were remarkably high (1.53 ± 0.70 and 0.90 ± 0.32, respectively). Conclusion Our proposed tissue-saving protocol (which showed satisfactory results in keratoconus cases according to a previously published article by our research team) has proven its successful outcomes (both topographically and visually) in cases of PMD, which is a rare ectatic entity with guarded prognosis using the available conventional ectasia treatment modalities.
Collapse
Affiliation(s)
- Mohamed Omar Yousif
- Ophthalmology department, Faculty of Medicine, Ain Shams University, Cairo, Egypt
- Maadi Eye Subspecialty Center, Cairo, Egypt
| | - Rania Serag Elkitkat
- Ophthalmology department, Faculty of Medicine, Ain Shams University, Cairo, Egypt
- Watany Eye Hospital, Cairo, Egypt
- Watany Research and Development Center, Watany Eye Hospital, Cairo, Egypt
- Ophthalmology Department, Faculty of Medicine, MTI University, Cairo, Egypt
| | - Mohamed Nabil Hamza
- Ophthalmology department, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | | |
Collapse
|
2
|
Manns RPC, Achiron A, Knyazer B, Elhaddad O, Darcy K, Yahalomi T, Tole D, Avadhanam VS. Use of corneal cross-linking beyond keratoconus: a systemic literature review. Graefes Arch Clin Exp Ophthalmol 2023; 261:2435-2453. [PMID: 36881260 DOI: 10.1007/s00417-023-05994-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 01/13/2023] [Accepted: 02/04/2023] [Indexed: 03/08/2023] Open
Abstract
PURPOSE The success of corneal collagen cross-linking in altering keratoconus' clinical course has driven a search for further uses of this procedure. This literature review aims to analyze the scientific evidence available for the benefit of cross-linking in the management of ophthalmic diseases other than progressive keratoconus or ectasia induced by corneal refractive procedures. METHODS A systemic literature review. RESULTS We reviewed 97 studies. We found that collagen cross-linking can limit the progression of several other corneal ectasias, thus reducing and limiting the need for keratoplasty. Collagen cross-linking also can reduce the refractive power of the cornea and can be considered for a moderate degree of bacterial keratitis or when the organism is unidentified, which is refractive to antibiotics alone. However, the comparative rarity of these procedures has limited the extent of evidence. In fungal, Acanthamoeba, and herpes virus keratitis, the evidence is inconclusive of the safety and efficacy of cross-linking. CONCLUSION Current clinical data is limited, and laboratory data has not fully correlated with published clinical data.
Collapse
Affiliation(s)
- Richard P C Manns
- Bristol Eye Hospital, University Hospitals Bristol NHS Foundation Trust, Lower Maudlin St., Bristol, BS1 2LX, UK
| | - Asaf Achiron
- Bristol Eye Hospital, University Hospitals Bristol NHS Foundation Trust, Lower Maudlin St., Bristol, BS1 2LX, UK
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Boris Knyazer
- Department of Ophthalmology, Soroka University Medical Center, The Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Omar Elhaddad
- Bristol Eye Hospital, University Hospitals Bristol NHS Foundation Trust, Lower Maudlin St., Bristol, BS1 2LX, UK
- Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Kieran Darcy
- Bristol Eye Hospital, University Hospitals Bristol NHS Foundation Trust, Lower Maudlin St., Bristol, BS1 2LX, UK
| | - Tal Yahalomi
- Department of Ophthalmology, Samson Assuta Ashdod Hospital and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Negev, Israel
| | - Derek Tole
- Bristol Eye Hospital, University Hospitals Bristol NHS Foundation Trust, Lower Maudlin St., Bristol, BS1 2LX, UK
| | - Venkata S Avadhanam
- Bristol Eye Hospital, University Hospitals Bristol NHS Foundation Trust, Lower Maudlin St., Bristol, BS1 2LX, UK.
| |
Collapse
|
3
|
Comparison of Visual, Tomographic, and Biomechanical Outcomes of 360 Degrees Intracorneal Ring Implantation With and Without Corneal Crosslinking for Progressive Keratoconus: A 5-Year Follow-up. Cornea 2020; 40:303-310. [PMID: 33543874 DOI: 10.1097/ico.0000000000002407] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 04/26/2020] [Indexed: 11/27/2022]
Abstract
PURPOSE To evaluate the long-term (5 years) results of 360 degrees intracorneal ring (ICR) implantation with and without corneal crosslinking (CXL) in patients with progressive keratoconus (KCN). METHOD This historical cohort study was performed on 35 eyes with progressive KCN, which was randomly divided into 2 groups. Fourteen patients were implanted only with ICR, and 21 patients with KCN were treated with ICR plus CXL simultaneously. Uncorrected distance visual acuity (UCDVA), corrected distance visual acuity (CDVA), and refractive components were collected from patients' medical records. The biomechanical properties of patients were measured using the Corvis ST (Oculus, Inc, Weltzar, Germany). Corneal topography and aberrometry parameters were also recorded from the Pentacam HR device (Oculus). RESULTS Both UCVA and CDVA increased in both groups after ICR implantation; however, this improvement was more significant in the ICR plus CXL group (P = 0.002 and P = 0.001, respectively). The mean improvement of CDVA in patients with ICR implantation with and without CXL was 0.56 ± 0.67 and 0.33 ± 0.61, respectively. A comparison of the long-term postoperative Tomographic and Biomechanical Index between 2 groups showed a better result in the ICR plus CXL group (P = 0.012). Topographic findings of the anterior corneal surface (flat-K, steep-K, mean-K, and astigmatism) after surgery were significantly better than before surgery in both groups (P < 0.05). CONCLUSIONS Although ICR implantation alone might halt the KCN progression with acceptable visual, topographic, and biomechanical outcomes, the combination of ICR and CXL has an adjuvant and synergistic effect, especially in long-term follow-up.
Collapse
|
4
|
de Almeida Ferreira G, Coral Ghanem V, Coral Ghanem R. Late progressive corneal flattening, haze and visual loss after eccentric crosslinking for Pellucid marginal degeneration. Am J Ophthalmol Case Rep 2020; 18:100621. [PMID: 32140613 PMCID: PMC7044711 DOI: 10.1016/j.ajoc.2020.100621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 11/20/2019] [Accepted: 02/17/2020] [Indexed: 11/17/2022] Open
Abstract
Purpose Observation Conclusion and Importance
Collapse
|
5
|
Yong JJ, Hatch KM. Corneal Cross-Linking: An Effective Treatment Option for Pellucid Marginal Degeneration. Semin Ophthalmol 2019; 34:512-517. [DOI: 10.1080/08820538.2019.1659832] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- JJ. Yong
- Department of Ophthalmology, Harvard Medical School,Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - KM. Hatch
- Department of Ophthalmology, Harvard Medical School,Massachusetts Eye and Ear Infirmary, Waltham, MA, USA
| |
Collapse
|
6
|
Pircher N, Lammer J, Holzer S, Gschließer A, Schmidinger G. Corneal crosslinking for pellucid marginal degeneration. J Cataract Refract Surg 2019; 45:1163-1167. [PMID: 31272773 DOI: 10.1016/j.jcrs.2019.03.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 02/01/2019] [Accepted: 03/15/2019] [Indexed: 11/25/2022]
|
7
|
Transepithelial Phototherapeutic Keratectomy Followed by Corneal Collagen Crosslinking for the Treatment of Pellucid Marginal Degeneration: Long-term Results. Cornea 2019; 38:980-985. [PMID: 31107284 DOI: 10.1097/ico.0000000000002003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE To evaluate visual, refractive, topographic, and aberrometric outcomes of transepithelial phototherapeutic keratectomy (PTK) + corneal collagen crosslinking in the treatment of pellucid marginal degeneration. METHODS This retrospective study includes 20 eyes of 15 patients with pellucid marginal degeneration treated with transepithelial PTK + accelerated corneal collagen crosslinking. Visual acuity, refraction, topographic keratometry, pachymetry, and aberrations were recorded pretreatment and 6, 12, 24, and 36 months after treatment. RESULTS Stabilization in visual acuity was observed throughout the 36 months of follow-up (P > 0.05). The cylindrical value was significantly lower (P < 0.05) during the follow-up compared with the baseline (4.97 ± 2.00, 3.86 ± 2.01, 3.92 ± 2.27, 2.87 ± 1.70, and 3.28 ± 3.12 D at the baseline and postoperative 6th, 12th, 24th, and 36th month, respectively). Spherical equivalent was significantly lower at the 24th (P = 0.02) and 36th month (P = 0.01) follow-up intervals. A significant decrease (P < 0.05) in average keratometry readings was observed in all follow-up points (47.12 ± 4.66, 46.65 ± 4.38, 46.57 ± 4.57, 46.46 ± 4.81, and 46.27 ± 4.46 D, respectively). The maximum keratometry value remained stable (P > 0.05) in all visits (64.30 ± 10.70, 63.49 ± 10.05, 62.97 ± 9.50, 63.33 ± 10.06, and 62.27 ± 10.36 D, respectively). The Baiocchi Calossi Versaci index was significantly lower (P < 0.05) at all follow-up points compared with the baseline (3.21 ± 1.93, 2.99 ± 1.96, 2.96 ± 1.93, 2.82 ± 1.95, and 2.86 ± 1.99 μm, respectively). Central and minimum corneal thicknesses were significantly lower (P ≤ 0.01) compared with the baseline throughout the follow-up. Higher order aberration, trefoil, coma, and spherical aberration values remained stable during the follow-up compared with the baseline (P > 0.05). CONCLUSIONS The combination of transepithelial PTK with accelerated corneal collagen crosslinking seems to be an effective treatment in patients with pellucid marginal degeneration in the long-term.
Collapse
|
8
|
Koc M, Kosekahya P, Inanc M, Tekin K. Corneal crosslinking in a case with Axenfeld-Rieger syndrome and unilateral pellucid marginal degeneration. Ther Adv Ophthalmol 2019; 11:2515841418822288. [PMID: 30729234 PMCID: PMC6350116 DOI: 10.1177/2515841418822288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 12/07/2018] [Indexed: 11/17/2022] Open
Abstract
A 31-year-old male patient presented with the complaint of progressive vision loss in his left eye. Slit-lamp examination showed posterior embryotoxon, iris hypoplasia, and iridocorneal adhesion in both eyes, corectopia in the right, and peripheral inferior thinning and ectasia in the left eye. Corneal topography showed slightly asymmetric bowtie pattern in the right eye and crab-claw pattern in the left eye. Topographic examination was compared with his previous topography. The comparison showed 1.6-D steepening of maximum keratometry (Kmax) and 22-µm decrease of thinnest corneal pachymetry. Corneal crosslinking treatment was performed on the left eye. At the postoperative 28-month follow-up visit, Kmax decreased from 54.1 to 53.0 D and corrected distance visual acuity improved to 20/20 with scleral lens. This is the first reported a case with Axenfeld–Rieger syndrome and pellucid marginal degeneration association. We suggest that corneal crosslinking can be useful for management of pellucid marginal degeneration and longer follow-up might be needed in order to corroborate the effectiveness of the corneal crosslinking procedure.
Collapse
Affiliation(s)
- Mustafa Koc
- Ophthalmology Department, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - Pinar Kosekahya
- Ophthalmology Department, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - Merve Inanc
- Ophthalmology Department, Ercis State Hospital, Van, Turkey
| | - Kemal Tekin
- Ophthalmology Department, Ercis State Hospital, Van, Turkey
| |
Collapse
|
9
|
Gu L, Shan T, Ma YX, Tay FR, Niu L. Novel Biomedical Applications of Crosslinked Collagen. Trends Biotechnol 2018; 37:464-491. [PMID: 30447877 DOI: 10.1016/j.tibtech.2018.10.007] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 10/19/2018] [Accepted: 10/19/2018] [Indexed: 02/08/2023]
Abstract
Collagen is one of the most useful biopolymers because of its low immunogenicity and biocompatibility. The biomedical potential of natural collagen is limited by its poor mechanical strength, thermal stability, and enzyme resistance, but exogenous chemical, physical, or biological crosslinks have been used to modify the molecular structure of collagen to minimize degradation and enhance mechanical stability. Although crosslinked collagen-based materials have been widely used in biomedicine, there is no standard crosslinking protocol that can achieve a perfect balance between stability and functional remodeling of collagen. Understanding the role of crosslinking agents in the modification of collagen performance and their potential biomedical applications are crucial for developing novel collagen-based biopolymers for therapeutic gain.
Collapse
Affiliation(s)
- Lisha Gu
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, PR China
| | - Tiantian Shan
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, PR China
| | - Yu-Xuan Ma
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases and Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China
| | - Franklin R Tay
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases and Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China; The Dental College of Georgia, Augusta University, Augusta, GA, USA.
| | - Lina Niu
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases and Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China; The Dental College of Georgia, Augusta University, Augusta, GA, USA.
| |
Collapse
|
10
|
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.
Collapse
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.
| |
Collapse
|