AIM: To determine the relation between each of the optical coherence tomography(OCT)patterns, etiologies and visual acuity in patients with cystoid macular edema(CME).

METHODS: Fifty-seven eyes with CME from 52 patients were included in our study. The data of this cross sectional study was collected from patients with CME assessed by OCT, who also underwent fundus photography and visual acuity test the same day. The best corrected visual acuity(BCVA)was assessed by using E chart and converted in logarithm of the minimum angle of resolution(logMAR). The visual acuity varied from 2.3 logMAR to 0 logMAR with a mean of 1.11±0.57. The etiology was determined from medical history and the fundus photograph of the patient. Four OCT grades established according to ratio between the vertical size of largest cyst and the maximum macular thickness(<30%, ≥30% <60%, ≥60% <90% and ≥90%)were considered. The correlation was established by calculating the Pearson's correlation coefficient “r” and the statistical significance was considered when P value was inferior to 0.05.

RESULTS: OCT grade IV was the most associated with very severe visual loss with the greatest mean VA of 1.96±0.23 logMAR and the correlation between OCT grades and visual acuity was strongly statistically significant(r=0.729, P<0.001). The central retinal vein occlusion(CRVO)was the most underlying disease associated with worse vision, with the greatest mean VA of 2 logMAR and the correlation was statistically significant(r=0.375, P=0.004). Another associated OCT pattern, the disruption of both inner segment/outer segment(IS/OS)and external limiting membrane(ELM), was inversely associated with severe visual loss(high mean VA=1.11±0.57 logMAR, with statistically significant correlation, r=-0.346, P=0.008). The presence of both vitreoretinal traction components and outer retinal layers disruption were significantly associated with OCT grade IV(r=0.390, P=0.003)and CRVO(r=0.362, P=0.006).

CONCLUSION: In this study, the OCT fourth grade and CRVO seem to be more significantly associated with the worse vision in patients with CME.