Macular Edema Morphology May Predict Visual Acuity in Diabetic Macular Edema

Macular edema morphology, regardless of subretinal fluid (SRF), is the strongest predictor of best corrected visual acuity (BCVA) in treatment-naïve patients with diabetic macular edema (DME), according to a study published in the International Journal of Retina and Vitreous. Cystoid macular edema (CME) subtype could serve as an independent predictor of poor BCVA in patients with DME, according to the report.

Researchers conducted a cross-sectional, observational, single center study on 52 eyes from 34 treatment-naïve patients (mean age, 56.17 years; 29 eyes were women) with DME between August 2021 and February 2022. Eyes were separated based on optical coherence tomography (OCT)-determined macular edema morphology into 2 groups: CME (n=27 eyes) and diffuse retinal thickening (DRT) (n=25 eyes), with further subdivision based on the presence of subretinal fluid. All participants had type 2 diabetes mellitus.

Each participant underwent 3×3 and 6×6 mm OCT angiography (OCT-A) scans of the macula to compare the foveal avascular zone (FAZ) area, vascular density (VD) of the superficial (SCP) and deep (DCP) capillary plexus and choriocapillaris flow (CF). The research team correlated the laboratory findings (HbA1C and triglyceride levels) with the OCTA findings.

Between both groups, there were no significant differences regarding VD of the SCP (P =.684) and DCP (P =.437), FAZ of SCP (P =.574), FAZ of DCP (P =.563) and CF (P =.311). Linear regression analysis showed that diabetic macular edema morphology was the factor most predictive of BCVA. Other significant predictors for BCVA included HbA1C and triglyceride levels.

“The morphology of macular edema (DRT versus CME); irrespective of SRF presence, was the factor most predictive of BCVA in patients with DME,” according to the researchers. “The presence of SRF did not have a significant effect on BCVA in the CME subgroups or DRT subgroups.”

This study was limited by the absence of patients with type 1 diabetes mellitus and patients with nephropathy.