Subfoveal choroidal thickness and its association with AMD in elderly French subjects: the ALIENOR study

Abstract

Purpose : Since the advent of enhanced-depth imaging optical coherence tomography (EDI-OCT), some studies have suggested that choroidal thickness may be decreased in age-related macular degeneration (AMD). However, results are inconsistent, and most studies are hospital-based with possible selection bias. Thus our objective was to examine the association of AMD with subfoveal choroidal thickness in a population–based study of French elderly subjects.

Methods : Alienor is a population-based cohort study on age-related eye diseases performed in elderly residents of Bordeaux, France. Spectral domain optical coherence tomography (SD-OCT) examinations were performed in 2011-2012, using Spectralis, (Software Version 5.4.7.0, Heidelberg Engineering, Heidelberg, Germany). Subfoveal choroidal thickness (SFCT) was measured manually on one horizontal scan obtained using the EDI mode. AMD was graded in 2011-2012 from non mydriatic color retinal photographs and SD-OCT and two exclusive stages were defined: no AMD (n=157 subjects with complete data, 342 eyes); any AMD (presence of neovascular AMD and/or geographic atrophy and/or soft distinct drusen and/or soft indistinct drusen and/or reticular drusen and/or pigmentary abnormalities) (n=104, 147 eyes). Associations between any AMD and SFCT were estimated using logistic Generalized Estimating Equations (GEE) models and were adjusted for potential confounders: age, gender, axial length, smoking, plasma HDL-cholesterol, and ARMS2 rs10490924 and CFH rs1061170 polymorphisms.

Results : In our study, 261 subjects (489 eyes) without missing data, aged 82.7 years on average were included. Among them, 59.4% were females. The mean SFCT was 201 µm (standard deviation (SD): 74.3) and the mean axial length was 23.5 mm (SD: 1.3). After multivariate adjustment, thicker SFCT was associated with a lower risk for any AMD (odds ratio [OR]=0.71 for 1 SD-increase in SFCT, 95% confidence interval [CI]: 0.53;0.94, p=0.02)

Conclusions : This study suggests that thicker SFCT may be associated with decreased risk for any AMD.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.