Purpose:
In eyes with intermediate age-related macular degeneration (AMD), hyperreflective foci seen on spectral domain optical coherence tomography (SDOCT) have been shown to correspond to hyperpigmentary changes on color fundus photography (CFP), a known risk factor for AMD progression. The purpose of this one-year analysis of eyes with intermediate AMD was to evaluate the change in quantity and distribution of SDOCT hyperreflective foci.
Methods:
This retrospective observational case series enrolled one eye with intermediate AMD per subject, as determined by CFP, from the randomized prospective AREDS2 Ancillary SDOCT trial. In a cohort of eyes with hyperreflective foci detected at baseline by certified SDOCT readers (Group A), the distribution of SD-OCT foci and AMD-associated pathology at baseline was compared with year one. Investigators and subjects remained masked as to nutritional supplements provided to subjects under AREDS2 protocol.
Results:
From 314 subjects enrolled in the clinical trial, 165 eyes (165 subjects) with baseline and year one SDOCT were enrolled into Group A. Based on SDOCT grading, non-central geographic atrophy (GA) increased from 21 to 55 eyes (p<0.001), central GA increased from 3 to 7 eyes (p=0.045), and possible advanced neovascular AMD increased from 8 to 20 eyes (p<0.001). The mean number of foci/eye increased from 2.2±1.5 to 2.6±1.8 at year one (p<0.001). There was an increase of +0.03±0.53 foci/eye in the central 500 microns of the fovea (p=0.48, non-significant), +0.17±0.85 foci/eye within 500-1000 microns (p=0.012), and +0.24±1.40 foci/eye outside 1000 microns (p=0.034). There was a mean increase in density of +0.29±1.44 foci/mm2 within 500-1000 microns (p<0.029), and a significant increase in proportion of foci in the inner retinal layers from baseline to year one (from 1.1% to 4.3%, p<0.001).
Conclusions:
In a paired longitudinal analysis of eyes with intermediate AMD and hyperreflective foci on SDOCT, the quantity and density of foci increased at one year, with an increased proportion of foci in the inner retinal layers. Detailed longitudinal follow-up may determine if tracking SDOCT foci in AMD can serve as a biomarker for disease progression.
Clinical Trial:
http://www.clinicaltrials.gov NCT00734487
Keywords: age-related macular degeneration • imaging/image analysis: clinical • retinal pigment epithelium