Abstract

To evaluate the restoration of outer segment ellipsoid zone (EZ) layer and its prognostic value in visual gain following resolution of macular edema (ME) due to branch retinal vein occlusion (BRVO). In this retrospective study,33 eyes of 33 patients with ME due to BRVO who underwent intravitreal ranibizumab (IVR) injections were studied. All of the patients had the resolution of macular edema after IVR therapy. At baseline and final visit, SD-OCT scans were obtained. Best-corrected visual acuity (BCVA), central macular thickness (CMT) and integrity of outer segment ellipsoid zone (EZ) defects were determined. We divided the eyes with initial EZ defects into two groups. Group-1 had restoration of EZ and group-2 had EZ defects before and after treatment. 14 of 33 eyes (42.4%) did not have EZ defects and 19 of 33 eyes had EZ defects before treatment. 9 eyes (27.3%) had restoration of EZ defects and 2 patients (6.1%) had EZ defects after treatment while they did not have at initial visit. According to EZ change status (group-1 and group-2) the groups were similar in terms of initial BCVA and CMT. Group-1 had better final BCVA (p=0.005). There was a statically significant difference in BCVA improvement between groups (p=0.001). Disorganization of photoreceptors can have recovery after resolution of ME with ranibizumab treatment and to have better BCVA after resolution of ME, restoration of the structure of the photoreceptors is required.

Key words: Branch retinal vein occlusion, macular edema, integrity of photoreceptors layer, optical coherence tomography