Abstract
Purpose:
To compare choroidal thickness (CT) in patients with intermediate and advanced age-related macular degeneration (AMD) with control subjects using semi-automated segmentation of the choroid in enhanced-depth imaging optical coherence tomography (EDI-OCT).
Methods:
194 eyes from 97 subjects (38 male, 59 female; mean age=70.3 years) who underwent spectral domain OCT (SDOCT) imaging at the Duke Eye Center from November 2010 to December 2011 as part of the Age-Related Eye Disease Study 2 Ancillary SDOCT (A2A-SDOCT) study, were evaluated using Heidelberg Spectralis EDI-OCT. Semi-automated segmentation of the choroid was performed, and CT was measured at the fovea, and at 0.5mm intervals up to 3mm nasal and temporal to the fovea. Eyes with high myopia >-6.0D or poor image quality (<75% choroidal-scleral junction visualized) were excluded. Stepwise multivariable linear regression was performed to evaluate the association of CT with systemic and ocular parameters, including age, smoking history, hypertension, diabetes mellitus, cardiac disease, visual acuity, refractive error, as well as central foveal thickness (CFT) and macular volume (MV). Mean subfoveal CT was compared between eyes with AREDS category 3 intermediate AMD (n=34), category 4 advanced AMD (n=25), and control subjects (n=132) using one-way ANOVA and a general linear model that accounts for age and refractive error as covariates.
Results:
Multivariable regression showed that subfoveal CT in all eyes correlated most with age and refractive error (β=-4.094, p<0.001; β=8.836, p=0.001; adjusted R-square=0.15), but not with smoking history, hypertension, diabetes, cardiac disease, visual acuity, CFT, or MV. Mean subfoveal CT was 240.02 +/- 94.66μm in controls, 222.41 +/- 99.73μm in intermediate AMD, and 210.00 +/- 95.09μm in advanced AMD (p=0.485). When adjusted for age and refractive error, mean subfoveal CT was 233.44 +/- 80.98μm in controls, 237.66 +/- 81.07μm in intermediate AMD, and 224.03 +/- 83.63μm in advanced AMD (p=0.883).
Conclusions:
When adjusted for age and refractive error, CT may not show significant thinning in intermediate or advanced AMD as previously described in some reports. Further studies are needed to characterize additional factors that may affect choroidal thickness in patients with AMD.
Keywords: 550 imaging/image analysis: clinical •
412 age-related macular degeneration •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)