Macular Optical Coherence Tomography Angiography Biomarkers Predict Regional Retinal Nonperfusion Patterns on...

Area of Science:

• Ophthalmology
• Diabetic Retinopathy
• Medical Imaging

Background:

• Diabetic retinopathy (DR) is a leading cause of vision loss.
• Assessing retinal ischemia in DR is crucial for management.
• Ultra-widefield fluorescein angiography (UWF-FA) visualizes peripheral retinal changes.

Purpose of the Study:

• To investigate the independent association of foveal avascular zone (FAZ) enlargement and geometric perfusion deficits in the deep capillary plexus (GPDd) with retinal nonperfusion.
• To evaluate these associations across different retinal regions using UWF-FA in diabetic patients.

Main Methods:

• Prospective, cross-sectional observational study of 159 eyes from 112 patients with diabetes.
• Quantification of retinal nonperfusion on UWF-FA (posterior, peripheral, total).
• Measurement of FAZ enlargement (structural vs. functional) and GPDd using OCT angiography (OCTA).
• Analysis using linear mixed-effects models.

Main Results:

• GPDd was significantly associated with nonperfusion in posterior, peripheral, and total retina.
• FAZ enlargement was associated with posterior nonperfusion but not peripheral.
• GPDd improved model fit for predicting nonperfusion across all regions, while FAZ enlargement only improved it for posterior nonperfusion.

Conclusions:

• GPDd is a reliable biomarker for retinal ischemic burden in all retinal regions in diabetes.
• FAZ enlargement specifically indicates posterior ischemia.
• OCTA-derived metrics offer complementary insights into regional retinal ischemia in diabetes, aiding stratification.