Evaluation of Foveal Avascular Region and Macular Blood Vessel Density in Prediabetic Patients with OCT-A Findings

Abstract

Abstract Purpose: This study aimed to compare the macular layer thickness, macular vessel density and Foveal avascular zone (FAZ) perimetric and areal OCT-A measurements of prediabetic patients with normoglycemic healthy subjects. Material - Methods: Thirty patients (Group A) with fasting plasma glucose (between 100-125 mg/dl), postprandial plasma glucose (between 140-199 mg/dl) and HbA1C (between 5.7-6.4%) values within the defined limits were included in the study. In addition, 30 healthy normoglycemic patients (Group B) were included as a control group. All participants underwent OCT-A to measure macular superficial capillary plexus (inner) and deep capillary plexus vessel density (outer) and foveal avascular zone width. Participants with poor image quality, refractive error, glaucoma, intraocular surgery, chorioretinal atrophy-like fundus findings and comorbid comorbidities were excluded from the study. Results: The perfusion density of the SCP and DCP decreased in the patient group compared to the control group and this difference was statistically significant in the inferior and temporal quadrants in the deep plexus and the temporal quadrant in the superficial plexus (p<0.05). Although there were changes around the foveal avascular zone and FAZ area between the groups, the difference was not statistically significant (p >0.05). Macular thickness was thicker in all quadrants in Group A, while the difference between nasal and inferior was statistically significant (p<0.05). Conclusion: Prediabetic patients showed increased macular thickness, decreased macular perfusion density and increased width of the FAZ in some patients. Although the results show that the disease affects ocular structures, more large-scale studies are needed to better understand the associated complications.