Purpose: To investigate the systemic and ocular factors associated with diffuse macular edema in patients with diabetic retinopathy (DR) and compare with patients with focal or no macular edema.
Methods: From 160 consecutive patients with DR, we obtained medical and ocular histories, blood pressure and visual acuity. Macular edema was determined by biomicroscopy and stereoscopic fundus photography. Fluorescein angiography was used in the characterization of its leakage, and the vitreoretinal relationship was performed by preset lens biomicroscopy.
Results: Among adult-onset diabetes mellitus (DM) patients, 55% had diffuse, 23.5% had focal and 21.5% had no macular edema (p=0.01). The risk of developing diffuse macular edema was 3.2 times greater in patients with high blood pressure (HBP) (95% confidence interval (CI), 1.5 to 6.9). Patients with cardiovascular disease (CVD) had a higher prevalence of diffuse (58.0%) than focal (26.0%) or no maculopathy (16.0%) (p=0.01). The odds for development of diffuse macular edema was 3.4 times greater in patients with vitreomacular adhesion (95% CI, 1.15 to 13.30) than in those with complete posterior vitreoretinal attachment or vitreoretinal separation. The odds for development of diffuse macular edema were 6.2 (95% CI, 1.83 to 21.04) and 7.7 times greater (95% CI, 3.12 to 19.12) in patients with PPDR and PDR, respectively, in comparison with those with NPDR.
Conclusions: In this study, adult-onset DM, HBP, CVD, vitreomacular adhesion and advanced retinopathy were associated with increased risk of development of diffuse diabetic macular edema.