Comparison of Autofluorescence Features between Optos UWF and Heidelberg Standard Field Autofluorescence

Abstract

Purpose : The current standard in fundus autofluorescence (FAF) imaging offers a 30° view of the retina, while more recent advancements in ultrawide field (UWF) FAF imaging offer imaging of up to 200° in a single image. The presence of reticular pseudodrusen (RPD) and certain geographic atrophy (GA) junctional zone patterns are associated with an increased rate of GA progression. This study aims to compare imaging of these features using standard and UWF FAF imaging.

Methods : Participants from the Age-Related Eye Disease Study 2 (AREDS2) and Optos PEripheral RetinA (OPERA) study with GA were included for comparison between standard FAF with Heidelberg Spectralis (Heidelberg Engineering Inc., Heidelberg, Germany) and Optos 200Tx UWF FAF (Optos PLC, Dunfermline, Scotland). GA area, presence of RPD and GA junctional zone pattern were evaluated for both imaging types.

Results : Of the 88 paired Heidelberg and Optos images (64 subjects) with GA, mean baseline GA area was 6.03 mm² (SD 6.54) as measured with Heidelberg and 5.45 mm² (SD 6.04) with Optos. GA was subfoveal in 41% vs 40% and multifocal in 68% vs 67% with Heidelberg and Optos, respectively. The region outside the macula showed GA in 2 eyes (2.3%) on Optos.

RPD was observed in 31 (35%) Heidelberg images and 8 (9%) Optos images. RPD was seen in Heidelberg but not in Optos in 23 eyes (26%), and there were no cases of RPD in Optos that were not seen in Heidelberg (fair agreement, kappa 0.31).

GA junctional zone pattern evaluation showed strong association (P < 0.001) between Heidelberg and Optos with exact agreement between imaging systems for 70 eyes (80%).

Conclusions : GA area measurement is comparable between Heidelberg and Optos UWF FAF along with foveal involvement and focality. However, RPD appears to be detected more often with Heidelberg. Differences may be due to field of view, image averaging, and resolution. Further investigation is required with recent developments in Optos UWF technology.

This abstract was presented at the 2024 ARVO Imaging in the Eye Conference, held in Seattle, WA, May 4, 2024.

 

Examples of GA as imaged by Heidelberg Spectralis (A) and Optos 200Tx UWF (B). The inset represents the standard field.

 

Junctional zone patterns imaged by Heidelberg (top) and Optos (bottom). Patterns include patchy (A, B), banded (C, D), diffuse (E, F), and none (G, H). RPD visible on Heidelberg (G), but not apparent on Optos (H).