Nonhuman Primate Eyes Display Variable Growth and Aging Rates in Alignment With Human Eyes

Abstract

Purpose To assess age-related biometric changes of the eye in nonhuman primates (NHPs), to and decipher the growth and aging rates and their comparability with humans. Methods Ocular anatomic measurements were performed on 341 macaca fascicularis aged 0.5 to 23 years via multimodal approaches including IOLMaster 700. Linear or polynomial regression models were simulated to determine the best fitted age-related function. The metrics were compared with human equivalents in published reports. Results Macaques exhibited a postnatal eye growth pattern similar to humans, characterized by continuous eye extension coordinated with dramatic reshaping of the lens but not the cornea. The age-related growth of lens thickness (LT), anterior chamber depth (ACD), and axis length (AL) exhibited nonlinear and bipolar patterns. The inflection points were 10 to 12 years old for LT and ACD and 13 to 15 years old for AL in macaques, which were comparable in chronological age at a ratio of ∼1: ratio with that in humans. In contrast, the speed of aging, including the increase in lens density and the decrease in retinal nerve fiber layer thickness, was comparable in relative age at a ratio of ∼1:3 according to the differences in lifespan between macaques and humans. Lens density was a robust indicator for the aging process. Conclusions Macaque eyes recapitulated the age-related process of human eyes to varying extents with different growth and aging rates. Chronological age or relative age should be considered in different scenarios when macaques are included in preclinical studies.

Comparison of the Accuracy of Seven Vault Prediction Formulae for Implantable Collamer Lens Implantation

“…Meanwhile, both the ZZ and Hun formulae incorporate LT. LT affects vault and is negatively correlated with the vault [ 29 ]. The LT size correlates with age and conditioning, with the LT becoming thicker as age progresses [ 30 ]. Most patients in this study were young, the LT was not thick, and the measurements were performed under a stable light source with no induced conditioning to cause the crystal to become convex, which may have contributed to the actual vault being higher than the predicted vault.…”