Optical Coherence Tomography Findings in Persistent Diabetic Macular Edema: The Vitreomacular Interface

Purpose: To assess the optical coherence tomography (OCT) characteristics of eyes with persistent clinically significant diabetic macular edema (PDME) after focal laser treatment, with emphasis on the vitreomacular interface (VMI) characteristics. Design: Prospective, observational case series. Methods: Fifty eyes with PDME after at least one focal laser treatment were enrolled prospectively. Slit-lamp biomicroscopy, stereoscopic fundus photography, fluorescein angiography (FA), and OCT were performed for each eye. The main outcome measures included the detection rate of VMI abnormalities (VMIA) by OCT in comparison with biomicroscopy, fundus photography, and FA (traditional techniques); the relationship between VMIA and the number of focal laser sessions per eye and FA leakage pattern. Results: Two of 50 eyes were excluded because of incomplete data. For the remaining 48 eyes, 25 eyes (52.1%) demonstrated definite VMIA, including anomalous vitreal adhesions, epiretinal membrane (ERM), or both, and six eyes (12.5%) had questionable VMIA. OCT in general was 1.94 times more sensitive than traditional techniques combined in detecting VMIA (P = .00003). The number of focal laser sessions and diffuse FA leakage were not associated with an increased prevalence of VMIA (P = .13 and P = .47, respectively). Conclusions: This study demonstrates a high prevalence of VMIA in eyes with PDME after focal laser treatment and underscores the superiority of OCT in detecting these abnormalities. OCT evaluation of eyes with PDME may be helpful in identifying VMIA, which may impact treatment selection and patient subgroup stratification.