In vivo cone-photoreceptor density comparison between eyes with subretinal drusenoid deposits and healthy eyes using high magnification imaging

To compare photoreceptor density automated quantification in eyes with subretinal drusenoid deposits (SDD) and healthy controls using Heidelberg Spectralis High Magnification Module (HMM) imaging.

Twelve eyes of 6 patients with intermediate AMD, presenting with SDD were included, as well as twelve eyes of healthy controls. Individual dot SDD within the central 30° retina were examined with infrared confocal laser ophthalmoscopy, HMM, and spectral-domain optical coherence tomography (SD-OCT). Photoreceptor density analysis was performed on the best-quality image using the ImageJ Foci Picker plugin, after the removal of SDD from the HMM image. Correlations were made between the HMM quantified photoreceptor density, SD-OCT characteristics, stage, and number of SDD.

Mean age was 75.17 ± 2.51 years in the SDD group (3 males, 3 females) versus 73.17 ± 3.15 years in the healthy control group (p = 0.2). Defects in the overlying ellipsoid zone were present on SD-OCT in 8/12 (66.66%) eyes. The mean ± standard deviation foci detected (i.e., cone photoreceptors) was 7123.75 ± 3683.32 foci/mm² in the SDD group versus 13,253 ± 3331.00 foci/mm² in the healthy control group (p = 0.0003). The number of SDD was associated with a reduction in foci density, p = 0.0055, r = − 0.7622.

The decreased cone density in eyes with SDD may correlate with a decrease in retinal function in intermediate AMD eyes independent of neovascular complications or outer retinal pigment epithelial atrophy.