Optical isoplanatic patch size across the visual field as a function of wavelength, pupil size, and accommodation in emmetropic and myopic eyes.

Changes in ocular aberrations over the visual field are relevant to ophthalmic imaging, peripheral laser therapies, the design of ophthalmic products, and the pathophysiology of ametropias. Cohorts of emmetropic and myopic eye models were used to quantify the isoplanatic patch - an angular field region of constant optical quality - as a function of visual field position, wavelength, pupil size, accommodation, and ophthalmic correction modality. At any visual field point, isoplanatic patches are larger for longer wavelengths and/or smaller pupil diameters than for shorter wavelengths and/or larger pupils. Average cohort patches are largest near fixation and decrease monotonically and roughly equivalently in all directions away from the fovea in a manner best fit by a double Gaussian, reflecting faster changes in patch size over the more central field. Approximately a 150 nm step in wavelength caused a statistically significant change in patch size, as did a 1 mm diameter change in pupil size, and a 4 D change in accommodative response. The myopic cohort had smaller isoplanatic patches (more rapid change in aberration structure) than the emmetropic cohort; significance depended on specific pupil sizes and wavelengths. Patch shape definitions, isoplanatic thresholds, optical metrics, and field sampling increments are compared; and differences between relative peripheral refraction and isoplanatic patch size are discussed. The results describe the trade-off of system- and eye-variables when optimizing retinal imaging. The relative change in the isoplanatic patch size relates to refractive cohort differences and the impact of ophthalmic products on the rate-of-change of peripheral aberrations and local retinal contrast.