Association between integrity of foveal photoreceptor layer and visual outcome in retinal vein occlusion

Purpose: To investigate the correlation between integrity of foveal photoreceptor layer and initial as well as final visual acuity (VA) after successful resolution of macular oedema (ME) associated with retinal vein occlusion (RVO). Methods: We retrospectively studied 31 eyes of 31 patients with resolved ME secondary to RVO. The integrity of foveal photoreceptor layer was studied using the junction between photoreceptor inner and outer segment (IS/OS) on spectral domain optical coherence tomography (SD OCT). The study eyes were categorized into three groups at final visit; V group with completely visible IS/OS, P group with partially detected IS/OS and I group with invisible IS/OS. Disrupted length of IS/OS and external limiting membrane (ELM) were measured. Results: Final VA (logMAR) was closely associated with the IS/OS integrity at final visit; final VA in V group (0.03 +/- 0.05) was better than that in P group (0.21 +/- 0.23) (p = 0.027) and final VA in P group was better than that in I group (0.70 +/- 0.36) (p = 0.004). Better initial VA (logMAR) and shorter length of disrupted IS/OS at initial visit were closely associated with better final VA (logMAR). In addition, final VA (logMAR) was closely associated with the length of disrupted IS/OS and ELM at final visit. Conclusions: After resolution of ME associated with RVO, the final VA is associated with the integrity of foveal photoreceptor layer. Better VA and the smaller length of disrupted IS/OS on SD OCT at initial visit are indicators of better visual outcome in patients with RVO.