Abstract
Purpose :
We investigated the determinants of the macular thickness (MT) and retinal nerve fiber layer (RNFL) thickness in eyes of healthy Latinos, considering the effects of genetic global ancestry, demographic characteristics, and clinical variables.
Methods :
Data were obtained from the Los Angeles Latino Eye Study (LALES), a population-based study of eye disease among Latinos. OCT was performed on participants during the 8-year follow up examination using the Cirrus HD-OCT. Imaging was completed using the Optic Disc Cube 200x200 (RNFL) and Macular Cube 512x128 (MT) protocols. We determined the proportion of Native-American, European, and African ancestry using ADMIXTURE from genotyping from the OmniExpress BeadChip. Participants with suspect or known glaucoma or low signal strength (<6) were excluded. Associations between RNFL and MT and potential covariates were assessed by univariate and multivariate linear regression.
Results :
OCT scans were available from 2,862 individuals. The mean overall RNFL thickness was 92.93±11.90 μm. The overall RNFL thickness was associated with age (p<0.0001), BMI (p=0.02), waist-to-hip ratio (p=0.02), being diabetic (p=0.005) and diabetic with any retinopathy (p=0.02), diastolic blood pressure (p=0.009), and axial length (p<0.0001). These same variables were also significantly associated with RNFL thickness in the superior and inferior quadrants. Only age, axial length, and diabetic severity were predictors in the nasal and temporal quadrants. The mean overall MT was 291.1±18.53 μm. Gender (p<0.0001), axial length (p=0.0009), and proportion of Native-American Ancestry (p=0.001) were significantly associated with central subfield MT thickness. Both inner and outer MT thickness were associated with gender, axial length, diabetic severity, and systolic/diastolic blood pressure (all p<0.05) but not ancestry.
Conclusions :
This large population-based study provides evidence on the relationship between genetic ancestry, demographic and clinical characteristics and OCT-derived measures of retinal structure in Latinos. Latinos are derived from multiple global populations. Therefore, ancestry could explain heritability of the retinal structure, specifically MT, and conditions related to its change. Studies utilizing OCT should consider effects of clinical determinants and ethnicity in imaging and diagnosing optic neuropathies.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.