Purpose: To describe various morphologic patterns of diabetic macular edema (DME) demonstrated by optical coherence tomography (OCT) and correlate them with visual acuity.
Design: Retrospective, observational, case series.
Methods: A retrospective review of all patients with DME who underwent OCT evaluation and met the study inclusion criteria between May 1998 and December 2002 at the Cole Eye Institute was performed. The OCT scans were evaluated for the presence of diffuse retinal thickening (DRT), cystoid macular edema (CME), posterior hyaloidal traction (PHT), serous retinal detachment (SRD), and traction retinal detachment (TRD). Additionally, the retinal thickness was measured and visual acuity evaluated.
Results: Two hundred seventy-six OCT scans of 164 eyes of 119 patients were identified. OCT revealed five morphologic patterns of DME: DRT (269, 97%), CME (152, 55%), SRD without PHT (19, 7.0%), PHT without TRD (35, 12.7%), and PHT with TRD (8, 2.9%). Mean retinal thickness varied depending on the morphologic pattern. The mean visual acuities (Snellen equivalent) also varied between groups. Increasing retinal thickness in all patterns was significantly correlated with worse visual acuity (P < .005). The OCT patterns containing CME (P = .01) and PHT without TRD (P = .02) were also significantly associated with worse vision.
Conclusions: DME exhibits at least five different morphologic patterns on OCT. There is a significant correlation between retinal thickness and visual acuity.