Addition of Blue Reflectance Image to Red Green 200° Ultra-widefield Images

Abstract

Purpose : The clinical utility of 200° colour ultra-wide field imaging using a red (635 nm) and green (532 nm) composite image (optomap) has been demonstrated in over 2000 peer-reviewed publications in a multitude of retinal conditions. [1-4]. This study was designed to determine whether the addition of a blue reflectance image (488nm) to the existing RG composite image generated by the Optos California P200DTx Scanning Laser Ophthalmoscope (SLO) provides a non-inferior image for retinal evaluation.

Methods : A prototype RGB device was used to collect a variety of images of diseased and normal retinas for evaluation. The composite RG image will remain unchanged on this product. Subjects were imaged under an IRB approved protocol in Houston, Texas on both the RGB prototype and on commercially-available California device.
Images from 15 subjects (30 eyes) normal and diseased eyes from various ethnicities were reviewed by three masked certified reading centre graders. The conditions included age-related macular degeneration, diabetic retinopathy, retinal tears, uveitis, choroidal melanoma, glaucoma, vein occlusions and retinitis pigmentosa.

Results : Images were pre-selected to maximize visible retinal area for a lesion to lesion comparison. 100% were gradable in both imaging modalities. The image assessment from the reading centre found the composite ultra-widefield RGB images were non-inferior to RG when visualizing lesions across a spectrum of diseases. Graders reported small differences in brightness and contrast along vessels, borders of the optic nerve head and definition of the edges of lesions in 16.6% of eyes.

Conclusions : This study introduces the blue laser in addition to the standard image generated by the red/green lasers into a single composite RGB image. This addition does not alter the non-invasive, easy to acquire in a small pupil (2mm), patient friendly and high resolution image of the prior ultra-widefield devices.
Long term studies are planned to determine whether this integrated RGB image can provide additional benefits that have previously been reported by other commercially approved devices using blue reflectance imaging.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.

 

RG Optomap

 

RGB Optomap