Delhi Journal of Ophthalmology

Change In Vessel and Perfusion Densities with Varying Signal Strengths on Optical Coherence Tomography Angiography

Saurabh Verma, Rohan Chawla, Amar Pujari 
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS, New Delhi, India

Editor-in-Chief, Delhi Journal of Ophthalmology, Dr R.P.Centre, AIIMS.

Corresponding Author:

Saurabh Verma (MD)
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS, New Delhi, India.

Received: 30-MAR-2022 Accepted: 15-MAY-2022 Published Online: 25-JUN-2022

Purpose: To evaluate change in vessel and perfusion densities with varying signal strengths on optical coherence tomography angiography (OCTA).

Materials and Method: Quadrant wise vessel densities and perfusion densities in superficial capillary plexus were measured using 3*3 mm OCTA scans. Images were obtained in 26 normal eyes, out of which 10 were finally evaluated to study the variations in the aforementioned parameters with signal strengths (SS) 8, 9 and 10.

Result: The total vessel and perfusion densities increased significantly from SS 8 to 10 and 9 to 10. The mean vessel densities along the superior, inferior, temporal and nasal quadrants showed a consistent increase in values with a progressive increase in the scan strengths. Similarly, the perfusion densities along all four quadrants also showed a progressive increase in the percentage values with increasing signal strengths. 

Conclusion: Even minor variation in signal strength of OCTA, even within the generally accepted scan strengths, affects the quantitative analysis. Therefore, future studies using OCTA must specify the signal strength of the scans for a head to head comparison or interval analysis.

Keywords :Octa; Signal Strength; Vessel And Perfusion Densities