Effect of silicone oil versus gas tamponade on macular layer microstructure after pars plana vitrectomy for macula on rhegmatogenous retinal detachment.

PURPOSE: To analyze structural changes in the macular retinal layers and sub-foveal choroidal thickness (SFCT) in eyes after macula-on rhegmatogenous retinal detachment (RRD) repair by pars plana vitrectomy with either silicone oil (SO) or gas tamponade, and the effect of these changes on visual acuity. PATIENTS AND METHODS: Retrospective study which included 26 eyes in the SO Group and 32 in the Gas Group. Optical coherence tomography (OCT) scans of the affected eyes were obtained before surgery, and 3 months after PPV in the Gas Group, and during silicone oil in situ and 3 months after SO removal, in the SO Group. Qualitative assessment of photoreceptor layer and foveal contour, along with quantitative assessment of macular retinal thickness and SFCT was performed. Postoperative OCT macular microstructural changes were recorded and correlated to corrected distance visual acuity (CDVA). Intraocular pressure (IOP) was measured preoperative and at 3 months post operative. RESULTS: There was a 2-line loss (from 20/28 preoperatively to 20/40 at final follow-up) of CDVA in the SO Group (p=0.051), while there was no statistically significant change in CDVA in the Gas Group (p=0.786). There was no significant correlation between CDVA loss and duration of silicon tamponade (r=-0.031, p=0.893). There was a statistically significant increase in IOP from its baseline to final follow-up of 0.7 mmHg in the SO Group (p=0.023) while there was no statistically significant change in IOP in the Gas Group. During silicone oil tamponade, there was approximately 11% and 5% of retinal and sub-foveal choroidal thinning respectively, which was moderately resolved following silicone oil removal. 20% (5/24) of eyes in the SO Group had qualitative flattening of foveal contour during SO tamponade that resolved after SO removal. CONCLUSION: Thinning of the macula was noticed after macula-on RRD repair with SO tamponade. Such thinning was only partially reversible after the removal of SO.

Reasons for the Late Presentation of Diabetic Retinopathy in Saudi Arabia: A Survey of Patients Who Presented with Advanced Proliferative Diabetic Retinopathy to a Tertiary Eye Hospital.

Purpose: This study aimed to understand the barriers that contribute to diagnostic and therapeutic delays in patients with advanced proliferative diabetic retinopathy (PDR). Patients and Methods: This cross-sectional study targeted patients with advanced PDR who never received any ocular intervention at King Khaled Eye Specialist Hospital in Saudi Arabia. An Arabic-language questionnaire was used to interview the participants over a period of 6 months. The questionnaire comprised sociodemographic questions followed by several sections to assess the causes of delay in diagnosis and management. Variables were analyzed descriptively and reported as numbers and percentages using SPSS 22. Results: A total of 338 patients were included in the study. Most patients were older than 50 years (60.4%), and decreased vision was the main complaint at presentation (81%). Vitreous hemorrhage was the most common diagnosis (46%). Patients' lack of knowledge about the importance of DR screening programs and problems with healthcare system screenings were the most frequent causes of delay in diabetic retinopathy (DR) diagnosis and management. Conclusion: DR is still a major cause of permanent blindness that is treatable with regular follow-up and timely management. Even though DR screening and treatment in Saudi Arabia have improved drastically over the last years, socioeconomic and health system factors remain barriers to the improvement of outcomes of DR.