Abstract:
Diabetic Retinopathy (DR) is a prevalent complication of Diabetes mellitus
(DM) that primarily affects the microvasculature of the retina. However, the early stages of
retinal microvascular changes can be challenging to diagnose during clinical examinations.
Fundoscopy is currently considered the standard method for detecting DR. To address this
issue, Optical Coherence Tomography Angiography (OCTA) has emerged as a novel
approach for visualizing capillaries in real-time. This study aimed to demonstrate a link
between morphological alterations in the retinal vasculature and HbA1c levels using two
techniques, fundoscopy and OCTA, also assessing the utility of OCTA in objectively
staging DR based on retinal microvascular changes and the potential of OCTA in detecting
subclinical disease that may not be visible with fundoscopy. It involved a cross-sectional
design with a sample size of 79 DM patients who fulfilled the inclusion criteria.
Participants were required to provide written consent after being informed about the study.
Detailed medical and ophthalmic histories were recorded, including HbA1c levels.
Fundoscopy was done first then, OCTA imaging was performed to visualize the retinal
vasculature. Various quantitative parameters were analyzed using specialized software.
Statistical analysis was done to look at the relationship between morphological alterations
and level of HbA1c. The results offered an insightful information about the correlation
between retinal vascular integrity and glycemic control. Our study found a strong
correlation between the stages of DR and vascular parameters acquired from OCTA. With
different characteristics like the area, perimeter, and circularity of the FAZ and
VD showing progressive microvascular abnormalities. There were only weak relationships
found between HbA1c levels and OCTA parameters. OCTA parameters, including RE
Circularity and LE FAZ Area, and several VD measurements showed statistically
significant association with DR stages. Thus OCTA provides an early detection of retinal
microvascular changes as compared to fundoscopy. The study also showed weak
relationship between HbA1c and duration of diabetes with stages of diabetic retinopathy.
