3-D OCT-based guinea pig eye model: Relating morphology & optics

Abstract

Newborn eyes are generally long-sighted, but during growth, the eye balances optical changes with its increasing length to ultimately achieve emmetropia, in which during relaxed distance viewing, objects are well focused on the back of the eye. Although much is known about the regulation of such growth, there is little information about the specific optical changes and/or potential adaptive changes. Animal models are instrumental in understanding refractive error development, and guinea pigs provide an important animal model for myopia, emmetropization and potentially accommodation. Combined measurements of 3-D corneal and crystalline lens surface shape (based on OCT) and wavefront aberrations (based on Laser Ray Tracing) allowed evaluation of the relative contributions of corneal and lens surface geometry to defocus, astigmatism and higher-order ocular aberrations in emmetropic guinea pigs. This study allowed for the first time, accurate morphological measurement of these parameters in awake animals, facilitating the characterisation of an accurate in vivo eye model.