Abstract
Purpose :
Hyperreflective foci (HRF) are a spectral domain- optical coherence tomography (SDOCT) finding which have been considered a risk marker for progression of age-related macular degeneration (AMD). The aim of this study is to identify the prevalence of HRF from SDOCT scans in eyes with intermediate AMD, characterize them, and correlate them with progression to geographic atrophy (GA) and choroidal neovascularization (CNV) over time. The SDOCT findings of HRF were also related to the color fundus photography (FP).
Methods :
Patients with intermediate AMD (AREDS severity scale 3 – 8) in one or both eyes with Heidelberg SDOCT volume scans, infra-red reflectance, and FP were included. Eyes with evidence of GA or CNV were excluded. SDOCT were reviewed for HRF using the following criteria: hyperreflective spot measuring at least 3 microns located at the level of the retinal pigment epithelium (RPE) or above, casting shadow on layers below. Additional characteristics included location within the retinal layers, association with drusen, and distribution within the OCT grid. The OCT annotations of HRF were overlaid on the corresponding FP to see the colocalization with pigment changes. Progression to GA or CNV was documented at years 1, 2 and 5.
Results :
HRF were seen in 59.3% (48 of 81 eyes from 41 participants) with a median distribution of 4 HRF per eye (interquartile range: 2-10). HRF were predominantly located in outer retinal layers (91.7%) and within the inner subfields of the OCT grid (47.9%). They were associated with drusen in 77.1% (37 eyes). There was a correlation between increasing AREDS severity scale and presence of HRF (p = 0.018). HRF on SDOCT were significantly associated with pigment on FP (χ2 = 11.757, p = 0.019). At 5 year follow up, there was an association between HRF and development of GA/CNV (RR: 8.21, p = 0.0021).
Conclusions :
HRF are associated with increasing severity of AMD and increased risk of progression to late AMD. The HRF association with drusen, accumulation in outer retinal layers, and correspondence with increased pigment on FP is indicative of RPE migration as suggested by previous research. HRF could be used as a prognostic marker for progression to late AMD.
This is a 2020 ARVO Annual Meeting abstract.