# Visualization of the Persistent Avascular Retina with Ultra-Widefield Green Reflectance Imaging

## TL;DR

This study found that green reflectance imaging in ultra-widefield fundus imaging helps detect the avascular retina more clearly in children with retinopathy of prematurity.

## Contribution

The study introduces green reflectance imaging as a superior method for visualizing the persistent avascular retina in retinopathy of prematurity.

## Key findings

- Green reflectance imaging showed significantly higher detection rates of the avascular retina compared to composite and red reflectance imaging.
- All participants reported clearer boundaries of the avascular area in green reflectance images.
- Green laser provides better visualization due to lower penetration into choroidal vessels.

## Abstract

Objectives: The aim of this study was to determine which color imaging facilitated easier detection of the persistent avascular retina (PAR) in ultra-widefield (UWF) fundus imaging in children undergoing retinopathy of prematurity (ROP). Methods: A total of 20 eyes of 10 children aged between 6 and 9 who underwent diagnostic and therapeutic procedures for ROP were included. Fundus images were obtained using Optos confocal scanning laser ophthalmoscopy (cSLO; Optos PLC, Daytona, Dunfermline, UK). The images were divided and recorded into three groups as original imaging (composite), red reflectance imaging, and green reflectance imaging. These images were prepared as a slideshow for 10 ophthalmology specialists and they were surveyed to determine in which color imaging the peripheral avascular area was more easily detected. The results were evaluated. Results: The rate of detecting the PAR in green reflectance imaging by the participants included in the study was found to be statistically higher compared to other colors of imaging (composite 0.63 ± 0.09 (0.5–0.8), red 0.12 ± 0.05 (0.05–0.2), and green 0.94 ± 0.06 (0.85–1), p < 0.0001). All respondents reported that the boundaries of the peripheral avascular area were more clearly defined in the UWF (Optos PLC, Daytona, Dunfermline, UK) green reflectance imaging. Conclusions: Each color imaging used in UWF fundus imaging helps to visualize different layers of the retina. Our study showed that retinal vascular endings appear more distinct due to the lower penetration of the green laser into the choroidal vessels. Based on these findings, we believe that UWF fundus green reflectance imaging is more useful for detecting and monitoring PAR.