# Multimodal imaging for early drusen detection: RM-SLO as a promising imaging approach

## TL;DR

This study shows that RM-SLO imaging is better at detecting early signs of AMD, including small drusen, compared to traditional eye imaging methods.

## Contribution

RM-SLO is shown to have superior sensitivity and clarity for detecting drusen, including small lesions missed by other modalities.

## Key findings

- RM-SLO detected drusen in 38.78% of eyes, significantly higher than OCT (22.05%), CFP (8.37%), FFA (5.32%), and FAF (4.18%).
- RM-SLO provided pseudo-three-dimensional visualization of both hard and soft drusen, including small lesions undetected by other methods.

## Abstract

This study aimed to evaluate the diagnostic performance of retro-mode scanning laser ophthalmoscopy (RM-SLO) in detecting drusen compared to conventional multimodal imaging. Additionally, it sought to explore the imaging characteristics of RM-SLO for early age-related macular degeneration (AMD).

In this cross-sectional study, 192 patients (263 eyes) were examined using color fundus photography (CFP), optical coherence tomography (OCT), fundus fluorescein angiography (FFA), fundus autofluorescence (FAF), and RM-SLO. Three retinal specialists independently reviewed all images for the presence of drusen. Detection rates across modalities were compared using Cochran’s Q-test, and imaging characteristics of hard and soft drusen were described.

RM-SLO detected drusen in 102 eyes (38.78%). This detection rate was significantly higher compared to other methods such as OCT (22.05%), CFP (8.37%), FFA (5.32%), and FAF (4.18%) (all p < 0.0001 vs. RM-SLO). OCT was superior to CFP, FAF, and FFA (p < 0.0001); CFP had statistically significant differences from FFA and FAF (p = 0.039; p = 0.001). While FFA did not reveal any statistically significant differences from FAF (p = 0.453). RM-SLO provided a clear pseudo-three-dimensional visualization, enabling the identification of both hard and soft drusen, including small lesions that were not captured by other modalities.

RM-SLO demonstrates superior sensitivity and imaging clarity for drusen detection compared to conventional multimodal approaches. Its ability to visualize small and morphologically distinct drusen highlights its potential as a promising tool for early AMD screening and clinical management.