# Optical Coherence Tomography Angiography–Based Evaluation of Foveal Avascular Zone and Macular Vessel Density in Prediabetic Patients

## TL;DR

This study uses OCTA to find early retinal changes in prediabetic patients, showing reduced blood vessel density and increased macular thickness compared to healthy controls.

## Contribution

The study identifies early microvascular and structural retinal changes in prediabetic patients using OCTA, suggesting subclinical retinal involvement.

## Key findings

- Prediabetic patients had lower superficial and deep capillary plexus perfusion densities in specific quadrants.
- Macular thickness was significantly greater in the nasal and inferior quadrants of prediabetic patients.
- FAZ area and perimeter were larger in prediabetic patients, though not statistically significant.

## Abstract

To assess macular layer thickness, macular vessel density, and foveal avascular zone (FAZ) parameters in prediabetic patients compared with healthy normoglycemic controls using optical coherence tomography angiography (OCTA).

Thirty prediabetic patients (group A; fasting plasma glucose 100-125 mg/dL, postprandial plasma glucose 140-199 mg/dL, glycated hemoglobin 5.7%-6.4%) and 30 age-matched normoglycemic subjects (group B) were included. The OCTA imaging was used to evaluate superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel densities, as well as FAZ area and perimeter. Participants with poor image quality, high refractive error, glaucoma, prior intraocular surgery, chorioretinal atrophy, or other ocular/systemic comorbidities were excluded.

TheSCP and DCP perfusion densities (PDs) were lower in the prediabetic group, with significant reductions in the inferior and temporal quadrants of the DCP and the temporal quadrant of the SCP (P < .05). The FAZ area and perimeter were larger in the prediabetic group but not statistically significant (P > .05). Macular thickness was greater in all quadrants in group A, with significant thickening in the nasal and inferior quadrants (P < .05).

Prediabetic patients demonstrated early microvascular and structural changes, including reduced macular PD, increased macular thickness, and FAZ enlargement. These findings suggest subclinical retinal involvement in prediabetes, warranting larger longitudinal studies.