Associations of choroidal thickness with vascular risk factors: the ALIENOR study

Abstract

Purpose : The choroid is a highly vascular ocular structure which may be directly influenced by vascular factors. However, few studies are available in this field. Thus, our objective was to study the associations of vascular risk factors with choroidal thickness in 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 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 Enhanced Depth Imaging mode. In 1999-2001, presence of vascular factors were assessed through face-to-face interviews and specific measurements, and included smoking (pack-years), blood pressure, body mass index (BMI), plasma low and high-density lipoprotein cholesterol (LDL and HDL respectively), total cholesterol, triglycerides and glucose. Mixed linear models were used to evaluate the age- and gender-adjusted associations SFCT with vascular factors. All variables which were significant in the age- and gender-adjusted models were then included in a multivariate model.

Results : In this study, 440 subjects (867 eyes) without missing data, aged 83.2 years on average were included. Among those subjects, 59.5% were females. The mean SFCT for the right eye was 205.1 µm (SD: 81.8) and for the left eye was 201.5 µm (SD: 83.7). Increasing age was significantly associated with thinner SFCT after adjustment for gender (-3.2 µm per year, p=0.0009). After adjustment for age and gender, SFCT was thinner in heavy smokers (>20 pack-year) (-26.0 µm, p=0.01) and in subjects with elevated plasma glucose (≥7.0 mmol/l) (-51.0 µm, p=0.01). No associations were found between SFCT and gender, BMI, systolic and diastolic blood pressure, plasma HDL, LDL, total cholesterol and triglycerides. In the multivariate model, older age (-3.0 µm per year, p=0.002), heavy smoking (-24.1 µm, p=0.02) and elevated glucose (-48.1 µm, p=0.01) were independently associated with thinner SFCT.

Conclusions : This study suggests an altering effect of age, smoking and plasma glucose on choroidal thickness.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.