Peripheral defocus, specifically hyperopic defocus, has been shown to exist. In addition, the retina has been shown to respond to defocus to produce axial length changes that may result in abnormal refractive error, such as myopia. One of the primary receptors that can detect this defocus is the cone photoreceptor, which has a wide variation of phenotype (cone numbers and distribution) and genotype. It becomes necessary to study how the phenotypic and genotypic variation may be modulated with peripheral defocus and ultimately refractive development. We intend to implement three primary techniques to probe for associations between peripheral refractive error, the phenotypic retina, and the underlying genotype. Patients will be selected in two groups. The first group will be hyperopes/emmetropes and the second group will be progressing myopes. Using the Indiana University AO SLO, we intend to count the underlying cone numbers across the retina at various eccentricities. This will be compared to refractive error measurements from across the eye obtained by through focus LSDC. The underlying strength of these techniques is that the two measures can be directly cross correlated with one another to know the exact cone numbers at the same refractive error. Finally, genetic screening will be employed to compare known variations in cone photoreceptors to our other measures.
A clinician interested in the progression of myopia seeks to finish his doctoral education and learn advanced optical and genetic techniques. The combination of these areas will lead to establishing an independent research career, and when taken with his clinical training, will allow his research to have significant impact on a health problem of enormous magnitude.