Associations Between Cerebral Amyloid Angiopathy, Cognitive Impairment, and Depressive Symptoms.

Across many species, including humans, refraction is typically hyperopic at birth with a wide distribution among individuals. Early postnatal development is characterized by a coordinated process of ocular growth in which visual feedback guides optical power and axial length toward optimal retinal focus. During this period, the two eyes grow in a synchronized manner, progressively shifting refraction toward emmetropia. This process of emmetropization involves coupled structural and optical changes of the cornea, anterior chamber depth, crystalline lens, and axial length. Deviations from this coordinated growth are associated with the development of refractive errors. Thus, defining normal trajectories of these ocular parameters is essential for understanding emmetropization and the genesis of refractive errors. Acquiring detailed ocular measurements in human infants is challenging. Given the close anatomical similarities between non-human primate and human eyes, rhesus monkeys provide a highly relevant model for studying early ocular development. Therefore, primate models offer a valuable opportunity to characterize how optical components contribute to the earliest phases of emmetropization. Primate studies have been instrumental in defining how visual experience influences eye growth. For example, experimental manipulations of image quality in infant monkeys confirmed that emmetropization is visually guided, with defocus inducing predictable, direction-specific changes in axial elongation and refraction. Many prior studies of refractive development in non-human primates have relied on control eyes from experimental paradigms in which visual input was manipulated in one eye, raising the possibility that such interventions may have influenced otherwise normal growth patterns in the contralateral eye. Longitudinal data describing typical, unmanipulated ocular development are comparatively limited. Qiao-Grider et al. characterized normal eye growth from infancy to adulthood in rhesus monkeys with unaltered vision in both eyes, with a focus on anterior ocular structures and their relationships with axial length. Although anterior ocular changes during emmetropization are now relatively well described, developmental changes in posterior ocular structures are less well characterized, particularly for the choroid and sclera. A recent longitudinal study using optical coherence tomography (OCT) in rhesus monkeys assessed postnatal retinal maturation and demonstrated significant increases in retinal thickness and changes in foveal morphology over the first year of life. In myopia, excessive axial elongation is characterized by thinning and remodeling of the choroid and sclera, but retinal thickness remains relatively stable. Therefore, defining normal choroidal and scleral thickness changes with age, particularly during early development when axial length is rapidly increasing, is critical for interpreting structural alterations associated with myopia.