Longitudinal Assessment of Peripapillary Microvasculature Using Optical Coherence Tomography Angiography in Cognitively Normal Adults

Introduction: To evaluate longitudinal peripapillary changes in cognitively normal older adults using optical coherence tomography (OCT) and OCT angiography (OCTA). Methods: Participants older than 50 years with no history of neurodegenerative disease or cognitive impairment were prospectively enrolled. OCT and OCTA images were obtained at the first visit and 2 years later. Results: The study comprised 189 eyes of 111 adults with a mean age (±SD) of 69.3 ± 5.8 years and mean follow-up of 2.1 ± 0.5 years. Woman experienced slower rate of decline than men in capillary perfusion density (0.000% ± 0.005% vs −0.002% ± 0.004%; P = .038) and retinal nerve fiber layer (RNFL) thickness (0.133 ± 1.617 µm vs −0.659 ± 1.431 µm; P = .008). At both timepoints, after controlling for sex, the capillary perfusion density (P < .001), capillary flux index (P < .001), and RNFL thickness (P = .005) were lower in older participants. The mean capillary perfusion density was higher in women than in men at both timepoints (P = .01 and P = .002, respectively), with no significant differences in the capillary flux index and RNFL thickness. Conclusions: In cognitively normal adults, there is a significant reduction in peripapillary capillary perfusion density, the capillary flux index, and RNFL thickness associated with aging beyond 50 years. Women had higher capillary perfusion density values with slower rates of change in capillary perfusion density and RNFL thickness. These values can serve as benchmarks, and variations could be suspicious for a pathologic process.