Comparisons of Visibility of Two-Color (RG) to Three-Color (RGB) Ultra-Widefield Images for Ten Types of Fundus Lesions.

Purpose: To compare the visibility of fundus lesions between RGB and RG images obtained with an ultra-widefield (UWF) fundus imaging device (Optos) for 10 types of fundus lesions.

Methods: UWF images from 30 patients representing 10 types of fundus lesions were analyzed: vessel sheathing, optic disc cupping, cotton wool spots, epiretinal membrane, laser photocoagulation scars, retinal drusen, retinal hemorrhage, retinal/choroidal detachment, chorioretinal atrophy, and macular degeneration. Three images of each type of lesion were used, and 26 board-certified ophthalmologists compared them. The raters compared the visibility of lesions on a five-point scale: RG significantly better = -2; RG slightly better = -1; equal = 0; RGB slightly better = +1; and RGB significantly better = +2. The Wilcoxon signed-rank test was used to determine the significance of the differences.

Results: RGB images were rated significantly more visually favorable than the RG images for all 10 lesions (P < 0.01). The greatest improvements in perceived visibility in RGB images were observed for vessel sheathing (50.7%), optic disc cupping (49.8%), cotton wool spots (46.9%), and an epiretinal membrane (46.7%). Conversely, macular degeneration (22.7%) and chorioretinal atrophy (25.1%) had minimal advantages in RGB images.

Conclusions: RGB imaging improves the visibility of white and superficial fundus lesions but adds little benefit for deeper located lesions.

Translational relevance: The results indicate that RGB imaging, which includes blue laser light, improves the visibility of superficial and white retinal lesions. These findings support the optimized use of color imaging modalities in clinical practice based on lesion characteristics.