Optical coherence tomography patterns of diabetic macular edema and their correlation with visual acuity

Aim: The aim was to identify and evaluate the patterns of diabetic macular edema (DME) currently known by optical coherence tomography (OCT) and correlation of these patterns with visual acuity. Patients and methods: OCT scans were done for 60 eyes of 36 patients with diabetes. OCT is used to define the pattern of DME and measure the central macular thickness (CMT). Analysis of data was done to evaluate the relationship between retinal thickness and visual acuity and prevalence of each different morphological subtype and investigate the presence of relationship between different patterns and visual acuity. Results: Our OCT‑based classification was as follows: group 1 had diffuse macular edema without cysts (35%), group 2 had cystoid macular edema (CME) (26.67%), group 3 had CME with serous retinal detachment (SRD) (16.67%), group 4 had SRD with diffuse thickening (8.33%), and group 5 had tractional macular edema (13.33%). Eyes with sponge‑like retinal swelling had the best‑corrected visual acuity. Best‑corrected visual acuity in eyes with CME and CME with SRD was significantly worse. Eyes with CME, CME with serous sensory detachment, and tractional had CMT significantly larger than eyes with diffuse retinal thickening. There was a reverse correlation between best‑corrected visual acuity and CMT at the fovea in eyes with diffuse thickening alone, whereas the correlation was not significant in eyes associated with CME or serous sensory detachment. Conclusions: Our study affirmed that OCT is very useful in routine assessment of DME and in detecting vitreoretinal traction and SRD undetectable on biomicroscopy.