Factors affecting visual prognosis in patients with retinal vein occlusion

Purpose: Planning treatment or avoiding unnecessary treatments in patients with retinal vein occlusion based on predicting the level of visual outcome after treatment. Materials and Methods: In the study, the files of the patients who were followed up with the diagnosis of retinal vein occlusion in the Retina unit of the Karadeniz Technical University Faculty of Medicine, Department of Ophthalmology between 2015 and 2021 were retrospectively analyzed. The diagnosis of retinal vein occlusion was made with the help of fundus examination, fundus fluorescein angiography (FFA), and optical coherence tomography (OCT). Records of 180 eyes of 180 patients diagnosed with retinal vein occlusion were analyzed. Spectral domain OCT (RTVue, Optovue, Inc., Fremont, CA) was performed on the patients, with initial and final central retinal thickness, vitreoretinal interface defects, ellipsoid zone status, retinal layer morphological disorder (DRIL), macular and subretinal edema status, and type of edema present. cystoid, diffuse) were evaluated. Ultra-wide field FFA (Optos, California, Optos PLC, Dunfermline, UK) was performed to evaluate the presence of ischemia, ischemic index, deterioration in the foveal avascular zone, and optic disc diameters. Pathologies at the vitreoretinal interface were evaluated with OCT. OCT also evaluated the presence of DRIL, the status of the ellipsoid zone, and the presence of serous retinal detachment. EZ was evaluated in the 1mm area centered on the fovea and was classified as intact or defective. In accordance with the purpose of the study, patients were grouped as decreased, unchanged and increased vision, and their relations with other parameters were examined. Correlation analyzes of best corrected visual acuity (BCVA) and other parameters were performed. The relationships between the gender of the patients and other parameters were examined. Finally, the changes within the OCT data and their changes according to the treatments applied were examined. 5 Results: Of the patients, 94 (52.2%) were female and 86 (47.8%) were male, with a mean age of 67.32 ± 10.7 years. The mean follow-up period of the patients was 48.3±27.6 months. Branch vein occlusion was observed in 123 (68.3%) patients, while 57 (31.7%) patients had central retinal vein occlusion. While 64 patients (52.0%) of BRVO patients were ischemic type, 59 patients (48.0%) were non-ischemic type. While 35 (61.4%) of CRVT patients were ischemic type, 22 (38.6%) were non-ischemic type. While the mean central macular thickness was 437.9±272.8 µm at the first visit, it was 283.6±143.4 µm at the last visit. The mean ischemic index of all patients was 0.3±0.24(0-0.93), while it was 0.273(0-0.93) in those who had RDVT and 0.253 (0- 0.85) in those who had CRVT. ERM was observed in 43 (23.9%), VMT in 1 (0.6%), and ERM+VMT in 1 (0.6%) patient, while no interfacial disorder was observed in 135 (75.0%) patients. While the ellipsoid zone could be selected in 76 (40.6%) patients, it could not be selected in 104 (57.8%) patients. While DRIL was present in 107 (59.4%) patients, DRIL was not observed in 73 (40.6%) patients. While macular edema was present in 119 (66.1%) patients, it was not observed in 61 (33.9%) patients. While 57 (31.2%) patients had cystoid type macular edema, 62 (34.4%) patients had diffuse type macular edema. Serous macular detachment was present in 87 (48.3%) patients, but not in 93 (51.7%) patients. While 44 (24.5%) patients did not receive any injection therapy, 27 (15.0%) patients received only steroid injection (subtenon triamcinolone or ozurdex), 63 (35.0%) patients received only anti-VEGF therapy and 46 (25%) ,5) the patient received both steroid and anti-VEGF injection therapy. BCVA decreased in 68 (37.7%) patients, remained unchanged in 28 (15.6%) and increased in 84 (46.7%) patients. While the mean BCVA was 0.92±0.77 logmar in the affected eye at the first visit, the BCVA was 0.91±0.93 logmar at the last visit. Conclusion: The low central macular thickness value measured at the time of admission and the presence of cystoid type macular edema rather than diffuse type may be good indicators of good prognosis in the estimation of BCVA at the last visit. Key Words: Retinal Vein Occlusion, OCT biomarkers, Ischemic Index, Anti-VEGF