Material and Methods: The study included 81 eyes of 41 patients, who do not have anterior segment pathology and any treatment before. After ophthalmologic examination of all patients, macular OCT images were taken, the presence and type of macular edema (focal thickening, diffuse thickening, cystoid), serous retinal detachment with the integrity of the ISOS band, and epiretinal membrane assets were evaluated. Macular volume and central retinal thickness measurements were also recorded. The correlation between visual acuity and each of the OCT results were evaluated.

Results: Decrease in visual acuity was detected by presence of macular edema, but this decrease was not statistically significant in focal thickening (p=0.11), whereas statistically significant in diffuse thickening and cystoid edema (respectively, p<0.0001, p=0.007). Serous retinal detachment did not has significant relationship between visual acuity (p=0.26), significant decrease in visual acuity was obtained in the presence of epiretinal membrane (p<0.0001). Visual acuity was also significantly reduced in patients with disruption of ISOS band (p<0.0001). Increase in macular volume decreased visual acuity, but it was not observed statistically significant (p=0.72), whereas increase in central retinal thickness was found to have significantly decrease in visual acuity (p=0.001).

Conclusion: Visual acuity reduces dramatically in patients with diabetic retinopathy by presence of especially diffuse and cystoid edema. The increase in central retinal thickness with edema affect in a negative manner to visual acuity and the existence of epiretinal membrane and condition of ISOS band seems to be effective on visual acuity. Keywords : Diabetic retinopathy, optical coherence tomography, visual acuity