Abstract
Purpose :
Hyperreflective foci are an independent risk factor for complete RPE and outer retinal atrophy in nnAMD (AREDS2 group Ophthalmology 2017). Our purpose is to analyse migration patterns of intraretinal hyperreflective foci (HRF), believed to represent RPE, through a retrospective review of longitudinal eye-tracked optical coherence tomography (OCT).
Methods :
Patients with nnAMD, ≥ 12-month follow-up with tracked OCT B-scans (interscan spacing ≤250 µm), and at least 1 eye with HRF arising from the RPE were identified. Eyes were categorized by deposit type (hard, soft, cuticular, subretinal drusenoid deposits). The presence of drusenoid pigment epithelial detachment (DPED) and cRORA was noted. Patients with co-existing macular disease were excluded.
Results :
Forty-four patients (61 eyes, 29 females), with a mean age of 79.4 years, and mean follow-up of 4.7 years were included. Twenty-seven eyes had DPEDs, and 29 had cRORA. Thirty-four eyes had mixed druse types, most commonly cuticular with soft drusen (23 eyes). On NIR, a radiating pattern (“bicycle spoke,” Figure 1) of HRF was present in 17/27 eyes with DPED. A comma-shaped configuration called “RPE plume,” believed to represent RPE tracking Henle fibres (Figure 2; Balaratnasingam et al Ophthalmology 2017) was detected in 29/61 eyes. In eyes developing cRORA, RPE migration typically occurred near the atrophic boundary.
Conclusions :
In eyes with nnAMD, longitudinal tracked-OCT identifies migration patterns of intraretinal RPE which appear specific to certain AMD phenotypes. These patterns may have important implications for predicting the occurrence and progression rates of cRORA. By recording locations of intraretinal HRF in x,y,z space, it will be possible to compute the rate of migration of individual cells or groups of cells.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.