Dissertation Defense: Yuanxin Guan, "Advancing Refractive Error Care Through Novel Methods of Measuring Prescription Lens and Ocular Distortion"

When

10 a.m. – 1 p.m., July 29, 2024

Where

Abstract:

Refractive error is one of the most common eye disorders worldwide, affecting over one billion people globally. Uncorrected refractive error can lead to severe vision problems. Therefore, optimizing vision using correction schemes is essential for elevating all aspects of life. Spectacle lenses are one of the most reliable and effective ways to correct refractive errors. Various procedures need to be undertaken for eyecare professionals to prescribe spectacles accurately. Verifying the prescriptions of an existing pair of spectacles is a standard first step for obtaining an objective estimation of the prescriptions before the subjective refraction exam. Existing clinical prescription measurement approaches are limited to specialized lensmeters, which are inaccessible to a large proportion of the population. To address this gap, a novel approach to measure prescriptions of spectacle lenses is developed to be a convenient, low-cost alternative to the current standard of care. This system is presented in Chapter Two with details. The measurements are analyzed and presented as proof of concept.

Correction schemes are valuable, yet they could be only a temporary solution to refractive error. To prevent refractive error on-set and progression, many attempts to find the causes of this process have been investigated over the years to find the root of the problem. This includes an extensive amount of animal model research as well as human research. One implication is the potential role of the retina in the myopia progression process, as shown by the findings of deprivation-induced, lens-induced myopia, and so on. These results give rise to the hypothesis that a purely physical stimulus on the retina level may trigger this development. Other physical stimuli, including chromatic aberration, have been investigated, but one such stimulus that has yet to be investigated is the presence of ocular distortion. In the third chapter, we will demonstrate a system that allows us to measure ocular distortion from retinal images of an artificial human eye model. Our system presents a first step towards answering the bigger question of whether distortions on the retinal level could lead to myopia progression. Besides the concept and setup, the results will be shown and evaluated in depth in Chapter 3. Ultimately, this dissertation lays the foundation for several optical imaging methods that could benefit refractive error care, enhancing patient outcomes, and improving life quality.