Abstract
Abstract: :
Purpose:To describe the morphologic characteristics of macular edema related to epiretinal membranes (ERM), diabetic retinopathy (DR) and retinal vein occlusions (RVO), and to investigate the correlation between retinal volume, thickness and visual acuity (VA). Methods: Eighteen patients with ERM, 15 with DR, 13 with central or branch RVO, and 20 healthy controls were included. OCT Radial Line Scans centered on the fovea were used to assess retinal thickness and volume. VA tests, slitlamp biomicroscopy and indirect ophthalmoscopy were performed on each subject. Results: Diffuse macular edema (DME) and cystoid macular edema (CME) could be identified and differentiated by OCT. In the ERM group 98% showed DME and 2% CME. In the DR group 60% showed DME and 40% CME. In the RVO group only 25% showed DME and 75% CME. Average foveal thickness in the ER, DR, RVO, and control group was 410± 122 µm, 365± 89 µm, 484± 212 µm, and 205± 21 µm, respectively. These differences were significant compared to controls (p<0.0001). Total macular volume in the ERM, DR, RVO, and control group was 8.9± 1.6 mm3, 8.8± 1.6 mm3, 9.8± 3.4 mm3, and 6.8± 0.2 mm3, respectively. These differences were also significant compared to controls (ER, DR p<0.0001, RVO p<0.0004). We found significant differences between VA in the ERM, DR, and RVO groups compared to controls (p<0.0001, p<0.0001, p<0.0063, respectively). In the ERM group VA was strongly correlated with the average foveal thickness (p<0.001, Rsq= 0.803) and moderately correlated with the total macular volume (p<0.003, Rsq= 0.57). Average foveal thickness and VA showed only mild correlation in the DR group (p<0.017, Rsq= 0.343) and no significant correlation in the RVO group. Total macular volume and VA were moderately correlated in the DR group (p<0.002, Rsq=0.505) and only mildly correlated in the RVO group (p<0.03, Rsq=0.362). Conclusions: The study showed that CME is more common in RVO and DR patients and less common in ERM patients. The relatively mild correlation, or lack of correlation, between VA and retinal thickness/volume in DR and RVO patients indicates that factors other than retinal edema affect VA in these diseases.
Keywords: diabetic retinopathy • imaging/image analysis: clinical • macula/fovea