Intereye Microvascular Differences in Patients With Same-Stage Diabetic Retinopathy Revealed by OCTA

Area of Science:

• Ophthalmology
• Medical Imaging
• Diabetology

Background:

• Diabetic retinopathy (DR) is a leading cause of vision loss.
• Assessing microvascular changes in DR is crucial for understanding disease progression.
• Intereye differences in retinal microvasculature may impact DR management.

Purpose of the Study:

• To evaluate microvascular intereye differences in diabetic patients with same-stage diabetic retinopathy (DR) in both eyes.
• To compare optical coherence tomography angiography (OCTA) metrics between the left and right eyes of diabetic patients.
• To investigate the relationship between DR stage and intereye microvascular asymmetry.

Main Methods:

• Cross-sectional study using swept-source 6x6 mm OCTA scans.
• Calculation of vessel density (VD) and fractal dimension (FD) in superficial and deep capillary plexuses.
• Measurement of foveal avascular zone (FAZ) parameters (area, perimeter, circularity) and assessment of intereye differences using linear mixed models.

Main Results:

• Significant intereye differences observed in 336 eyes from 168 diabetic patients.
• Lower VD and FD in the superficial capillary plexus of the left eye compared to the right eye (P < 0.01).
• Increased FAZ impairment (lower circularity, higher asymmetry) in the left eye, particularly in more advanced DR stages.

Conclusions:

• OCTA metrics reveal significant intereye differences in retinal microvasculature in diabetic patients.
• The left eye shows a trend towards reduced vessel density and fractal dimension, and impaired FAZ characteristics compared to the right eye.
• These findings highlight the importance of considering intereye asymmetry in the assessment and management of diabetic retinopathy.