The Correlation Between Macular Vessel Density and Its Clinical Parameters in Diabetes Mellitus Type 2

To evaluate macular vessel density using clinical parameters in patients with type 2 diabetes mellitus (DM) without retinopathy.

This cross-sectional study enrolled 32 participants (63 eyes) aged 40-60 years who met the inclusion criteria. Group 1 included 32 eyes of type 2 DM, whereas the rest had no DM. Ophthalmic examination was performed. Macular vessel density was measured using optical coherence tomography angiography (OCTA) with a 6 × 6 mm scan. Macular vessel density is correlated with patient age, HbA1c values, disease duration, and contrast sensitivity. The data were analyzed using Spearman's rank correlation and an independent t-test.

Central (foveal area) macular vessel density in the diabetic group (5.36 ± 2.87) was significantly lower than that in healthy participants (7.82 ± 3.05) (p = 0.002). The whole macular vessel density (foveal and parafoveal areas) was also lower in the DM group than in the healthy subjects (15.76 ± 3.38 vs 17.18 ± 1.92) but the difference was not statistically significant (p = 0.070). The age of DM patients has correlated with central (r = -0.522; p = 0.002) and whole macular vessel density (r = -0.369; p = 0.038). HbA1c levels, diabetes duration, and contrast sensitivity were not correlated with macular vessel density.

Macular vessel density was lower in DM patients without retinopathy than in healthy subjects. In patients with DM, macular vessel density decreases with increasing age. We failed to find a correlation between macular vessel density and the HbA1c value, disease duration, or contrast sensitivity.