Objective: To investigate the effect of the largest intraretinal cyst diameter in the macula on visual and anatomical outcomes after intravitreal ranibizumab (IVR) treatment in cystoid macular edema (CME) secondary to branch retinal vein occlusion (BRVO).

Methods: Forty-two eyes of 42 patients who underwent IVR treatment for CME secondary to BRVO were studied retrospectively. Patients were evaluated after three-monthly IVR injection. The pre-treatment and post-treatment spectral domain optical coherence tomography parameters and best-corrected visual acuity (BCVA) were recorded. The effect of pre-treatment intraretinal cyst diameter on post-treatment central macular thickness (CMT) and BCVA was investigated.

Results: There were 27 (64.3%) men and 15 (35.7%) women in the study. The mean age was 59.5±9.6 years. The mean pre-treatment CMT was 485±160 µm and the mean pre-treatment BCVA was 0.84±0.55 logMAR. After 3 doses of IVR, CMT gain was 201±168 µm and BCVA gain was 0.41±0.43 logMAR. The mean pre-treatment cyst diameter was 241±121 µm. Although there was a low degree positive correlation between pre-treatment cyst diameter and CMT gain, this correlation was not statistically significant (r=0.245, p=0.059). Although there was a low degree negative correlation between pre-treatment cyst diameter and BCVA, this correlation was not statistically significant (r=-0.145, p=0.184).

Conclusion: There was no statistically significant correlation between pre-treatment cyst diameter and CMT and BCVA gain in CME treatment secondary to BRVO.