Abstract
Purpose: :
To identify spectral domain optical coherence tomography (SD-OCT) features in eyes with early age-related macular degeneration (AMD) which predict transition to neovascular AMD (NVAMD) within the next 12 months.
Methods: :
From a database of AMD cases at our institute we retrospectively selected all eyes that transitioned to NVAMD with complete SD-OCT documentation (macular cube scans, 512x128) available using either a 3D-OCT-1000/2000 or Cirrus HD-OCT. All scans were taken within 12 months prior to the clinical diagnosis of choroidal neovascularization (CNV). SD-OCT scans from an equally sized control group of patients with high risk (AREDS 3 or 4) early AMD who did not transition to NVAMD in the following 12 months were also selected. The masked scans from both groups were then randomized and independently graded by two reading center certified graders followed by open adjudication of any discrepancies. Graded parameters included: Presence of a break in the retinal pigment epithelium(RPE)-band, thickening or thinning of the RPE-band, RPE-band integrity, internal reflectivity of the pigment epithelial detachments (PED, homogeneous hyper/hypo, heterogeneous), presence of retinal atrophy, presence of an epiretinal membrane (ERM), or simplified quantification (# of B-scans, maximum height) of any subretinal fluid (SRF), cystoid macular edema (CME), or intraretinal hyperreflective foci (HRF). The chi-square test and a multivariate logistic regression model were used for statistical analyses.
Results: :
23 eyes from the transitional group (TG) and 23 control eyes were included in the analysis. There was no significant difference in the presence of an ERM (8 versus 9, p=0.574) or atrophy (5 versus 8, p=0.448) between the respective groups. After backward elimination, the logistic regression model showed a significant predictive power of HRF (>10 B-scans, odds ratio (OR) 6.18, 95% confidence interval (CI) 1.03 to 37.13), internal PED reflectivity (OR 7.92, CI 1.02 to 61.51), and retinal atrophy (OR 0.07, CI 0.01 to 0.72) with regard to transitioning to NVAMD. Interestingly, 4 eyes in the TG showed a subtle presence of SRF and/or CME on SD-OCT, although clinically they had been classified as dry AMD at that timepoint.
Conclusions: :
Non-neovascular AMD eyes with hyperreflective foci or PED with heterogenous internal reflectivity on OCT seem to be at risk for imminent development of CNV. While validation in a prospective series is warranted, we advise close monitoring of patients exhibiting these features.
Keywords: imaging/image analysis: clinical • age-related macular degeneration • clinical (human) or epidemiologic studies: risk factor assessment