Abstract
Purpose:
We aimed to analyze the changes in retinal and choroidal thickness in healthy elderly people over 65 years of age. The relationships between retinal and choroidal thickness on EDI-OCT and major AMD-associated SNPs were also evaluated.
Methods:
A population-based, prospective cohort study in Korean elders aged 65 year and older was conducted. Among the participants, spectral domain optical coherence tomography (SD-OCT) and blood samples were obtained from 352 individuals. Thickness of the retina and choroid were measured according to the ETDRS subfields. The subfields were grouped into mean minimal foveolar thickness (MMFT), central foveolar thickness (CFT), mean central thickness (MCT), mean peripheral thickness (MPT) and mean total region thickness (MTT). Subfoveal choroidal thickness (SFCT) was also measured on EDI-OCT. Statistical analysis was done to evaluate the correlation of thickness with age and gender. Each individual was also genotyped for the major AMD-associated SNPs - rs800292 and rs1061170 from CFH gene, and rs10490924 from ARMS2. Correlation with the genotype and retinal or subfoveal choroidal thickness was further explored.
Results:
Data from 255 individuals with an average age of 76.7 years were available for analysis. The mean retinal thicknesses were - MMFT 217.3㎛ (± 21.4), CFT 264.7㎛ (± 24.1), MCT 326.6㎛ (± 20.3), MPT 288.8㎛ (± 59.3), MTT 303.0㎛ (± 29.9), retinal nerve fiber layer (RNFL) thickness 95.2 ㎛ (± 11.9) and SFCT 181.5 ㎛ (± 69.1). The overall decrease in thickness was observed in the RNFL, MCT, and SFCT. With aging, the thickness declined at the rate of 6.17 ㎛ / 10yrs (p<0.001) in RNFL, 6.02 ㎛/ 10yrs (p=0.003) in MCT, and 2.78 ㎛/yrs (p<0.001) in SFCT. CFT and MCT were thicker by 8.45 ± 2.99 um (p=0.005) and 5.82 ± 2.50 um, respectively, in males than females. The genetic analysis showed an association between SFCT and CFH rs10611700 (Y402H).
Conclusions:
Age and gender-related differences of retinal and choroidal thickness exist in the normal healthy geriatric population. Acquisition of such normative data and genetic analysis in healthy eyes may provide insight on the pathophysiology of retinal and choroidal diseases.