Clinical Ophthalmology (Feb 2024)
Application of a Revised Tissue Saving Protocol for Combined Topography-Guided Photorefractive Keratectomy and Cross-Linking in a Cohort Having Pellucid Marginal Degeneration
Abstract
Mohamed Omar Yousif,1,2 Rania Serag Elkitkat,1,3– 5 Mohamed Nabil Hamza,1 Noha Abdelsadek Alaarag1 1Ophthalmology department, Faculty of Medicine, Ain Shams University, Cairo, Egypt; 2Maadi Eye Subspecialty Center, Cairo, Egypt; 3Watany Eye Hospital, Cairo, Egypt; 4Watany Research and Development Center, Watany Eye Hospital, Cairo, Egypt; 5Ophthalmology Department, Faculty of Medicine, MTI University, Cairo, EgyptCorrespondence: Rania Serag Elkitkat, Email [email protected]; [email protected]: 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.Keywords: pellucid marginal degeneration, recent treatment options for PMD, combined PTK and CXL for PMD, tissue saving protocol for PMD treatment, revised cross-linking with PTK for PMD
