Abstract
Purpose :
We previously reported a novel method for visualizing drusen using flood illumination adaptive optics (FIAO) ophthalmoscopy that exploits gaze-dependent contrast variations to detect drusen with high contrast and resolution [Rossi et al. TVST 2021;10(14):19]. Here we expand on that method by comparing gaze-dependent FIAO images to adaptive optics scanning laser ophthalmoscopy (AOSLO) and extend this approach to other maculopathies: pigment epithelial detachment, subretinal drusenoid deposits (SDDs), retinal pigment epithelium (RPE) atrophy, small hard exudates, serous retinal detachment and poppers maculopathy.
Methods :
A FIAO fundus camera (rtx1, ImagineEyes, France) was used to acquire a 4°×4° fovea-centered image and then its internal fixation target was moved to obtain 4–8 additional, overlapping images, with gaze displaced by +/- 2° vertically and horizontally (n=182 eyes). Custom software registered images and calculated the standard deviation (SD) of each pixel across areas of overlap. A subset of patients were imaged following the same protocol on AOSLO (PSI, Massachusetts) for multimodal comparison and investigation into gaze dependent imaging (GDI) in scanning technology.
Results :
Gaze-varying structures were not detected in controls. GDI is effective if each image is in focus and precisely aligned. With GDI in FIAO, drusen were detected in patients with high contrast and clear structural delineation. While GDI of drusen shows a bright annulus, GDI of pigment epithelial detachment showed an irregular bright annulus; SDDs and RPE atrophy were lower contrast than drusen; small hard exudates showed punctuate gaze-dependent variability, while serous retinal detachment and poppers maculopathy did not show enhanced contrast by GDI. Gaze-dependent AOSLO detected drusen (figure) with differences in contrast between split and confocal modalities.
Conclusions :
Gaze-dependent imaging in FIAO and AOSLO images allowed for visualization of microstructural features such as drusen via contrast enhancement. Our method shows individual drusen delineation that furthers our capacity to detect, map, measure, and monitor progression of drusen. Multi-modal comparison is essential to build a correct and complete interpretation of gaze dependent retinal structures, therefore extension of our method to scanning technology is beneficial, despite the difficulties of removing scan related-distortions.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.