Longitudinal Rate of Change of Peripapillary Optical Coherence Tomography Angiography Metrics in Cognitively Normal Older Adults

Abstract

Purpose : With increasing interest in the role of retinal and optic nerve biomarkers in age related and neurodegenerative diseases, it is important to characterize the velocity of normal age related changes in the retina and optic nerve. We evaluated longitudinal peripapillary changes in cognitively normal older adults using optical coherence tomography (OCT) and OCT angiography (OCTA).

Methods : Participants over 50 years old with no history of neurodegenerative disease or cognitive impairment were enrolled. Exclusion criteria included retinal or optic nerve pathology, glaucoma, diabetes, uncontrolled hypertension, corrected visual acuity less than 20/40 on day of imaging. The Zeiss Cirrus HD-OCT 5000 with AngioPlex was used to obtain OCT and OCTA images at baseline and two years later. OCTA parameters measured were optic nerve head-centered capillary perfusion density (CPD) and capillary flux index (CFI). OCT was used to measure retinal nerve fiber layer (RNFL) thickness. Generalized estimating equations were used to account for measurements obtained from two eyes of the same subject.

Results : 189 eyes of 111 cognitively normal older adults were analyzed (average age at baseline, 69.3 ± 5.8; average Mini-Mental State Examination score at baseline, 29.54 ± 0.71; 86 women [77.5%]). Average follow up was 2.1 ± 0.5 years. After controlling for sex, CPD (p < .001), CFI (p < .001), and RNFL thickness (p = 0.005) decreased with increasing age at both cross-sectional time points. Over the follow-up period, the rate of change in CPD, CFI, and RNFL thickness was not significantly correlated with age; however, the rate of change in CPD (p = .038) and RNFL thickness (p = 0.008) was slower in females compared to males. Average CPD was higher among female patients at both time points compared to males (p = .002) with no significant differences in CFI and RNFL thickness.

Conclusions : In cognitively normal adults, there is a significant reduction in peripapillary CPD, CFI, and RNFL thickness associated with aging beyond 50 years old. Females had higher CPD values with slower rates of change in CPD and RNFL thickness. These values can serve as benchmarks of normal aging and help detect accelerated rates of decline in neurodegenerative diseases.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.