Analyzing Relative Flow Speeds in Diabetic Retinopathy Using Variable Interscan Time Analysis OCT Angiography

Area of Science:

• Ophthalmology
• Medical Imaging
• Vascular Biology

Background:

• Diabetic retinopathy (DR) is a leading cause of vision loss.
• Understanding microvascular changes in DR is crucial for effective treatment.
• Current OCT angiography (OCTA) methods have limitations in assessing blood flow dynamics.

Purpose of the Study:

• To analyze relative blood flow speeds in the microvascular changes associated with diabetic retinopathy (DR) using the VISTA algorithm.
• To explore the potential of VISTA as an extension of OCTA for assessing DR.
• To correlate blood flow characteristics with DR severity and specific vascular abnormalities.

Main Methods:

• A cross-sectional study involving 13 patients with varying DR severity.
• OCT angiography images of the fovea were acquired using a swept-source OCT device.
• The Variable Interscan Time Analysis (VISTA) algorithm was applied to visualize relative blood flow speeds.

Main Results:

• Microaneurysms, IRMAs, and neovascularization were linked to slower blood flow.
• Different DR features exhibited distinct flow patterns: slow for microaneurysms, turbulent for IRMAs, and variable for neovascularization.
• Increased DR severity correlated with globally slower flow speeds, particularly around the foveal avascular zone.

Conclusions:

• The VISTA algorithm provides valuable insights into DR pathogenesis by visualizing blood flow.
• VISTA overcomes limitations of standard OCTA, offering a potential tool for improved DR assessment.
• These findings enhance understanding of the pathogenic microvascular changes in diabetic retinopathy.