Ophthalmology Commons^™

Role Of Meibum And Tear Phospholipids In The Evaporative Water Loss Associated With Dry Eye., Samiyyah M. Sledge

Electronic Theses and Dissertations

It is generally believed that the tear film lipid surface film inhibits the rate of evaporation (Revap) of the underlying tear aqueous. It is also generally believed that changes in the composition of the tear film lipid layer is responsible for an increase in Revap in patients with dry eye. Both of these ideas have never been proven. The purpose of the current studies was to test these ideas. Revap was measured in vitro gravimetrically. Lipid spreading was measured using Raman spectroscopy and microscopy. The influence of the following surface films on the Revap of the sub phase of physiologically …

Genetic Modification Of Inherited Retinopathy In Mice, Yang Kong

Electronic Theses and Dissertations

The retina, as a critical component of the sensory system, consists of multiple cell types, of which, photoreceptors play a key role in receiving, integrating and transmitting light signals. The biofunctions of photoreceptors rely on their proper growth and development, which is predominantly governed by a cluster of molecules that comprise the transcriptional regulation for photoreceptor development. Any disruption of these molecules potentially incurs retinal pathologies.

It is known that deficiencies of nuclear receptor subfamily 2 group E member 3 (NR2E3) or neural retina leucine-zipper (NRL), two molecules in regulating photoreceptor cell development, cause photoreceptor dysplasia. In a sensitized chemical …

Basic Vision Research With Clinical Applications And Science Education Assessments, Andrew Wilson

Electronic Theses and Dissertations

Visual Acuity (VA) examinations are one of the most commonly conducted medical assessment throughout the world. Recent advances in computer technology allows for new forms of visual assessment to be conducted. In Part I of this thesis I demonstrate the capability of an automated computer program named VISION to assess human visual acuities. Different color combinations of an object against a background emitted from a computer screen are used to examine a variety of human color vision acuities. Results indicated a large difference in acuity scores between human subjects tested with these different color combinations. A single human subject exhibits …

Retinal Synaptic Function In The Absence Of The On Pathway., Kathryn Marie Heath Fransen

Electronic Theses and Dissertations

Complete Congenital Stationary Night Blindness (cCSNB) is a rare hereditary retinal disorder characterized by abnormal night vision. cCSNB is caused by postsynaptic defects in On bipolar cells (BCs) and is identified by the presence of an electroretinogram (ERG) with a normal a-wave, corresponding to photoreceptor function, and the absence of a b-wave, corresponding to a failure of On BC function. Through the study of genetic mutations in mouse that result in no b-wave ERG phenotypes, several proteins have been identified that play crucial roles in On BC signal transmission. I focused on four mouse models of cCSNB; Nyxnob (Nyctalopin mutant), …

Boundary Contour Based Surface Representation., Yong Su

Electronic Theses and Dissertations

We receive most information about our surrounding space and objects through the eyes. To reconstruct the 3D space and objects in the visual system from the 2D retinal images, surface representation must be a critical intermediate stage in the visual processing stream. It is hypothesized in the dissertation that the visual system represents textured surface by a border-to-interior strategy: boundary contours would be encoded first and then border-ownership assignments would be resolved. This process would solve the related problems such as figure-ground segregation, surface depth relationship, occlusion, transparency, etc. As a result, the boundary contours of the surfaces would be …

Photodisruption In Ocular Tissue Near And At The Boundary Between The Anterior Chamber And Crystalline Lens, Richard Ty Olmstead

Electronic Theses and Dissertations

Lasers have been involved in Ophthalmology in the treatment of myopia and hyperopia for several years. Laser systems have transformed patients‟ quality of life, freeing them from the need for glasses, as in the case of LASIK. Ultrafast lasers have played an important role in surgery of the eye. In LASIK, they are used to cut the flap that is lifted to expose the stroma for UV Excimer laser treatment of this region. They are now being used for surgery deeper into the eye,for instance, treating the lens as part of treatments for cataract surgery. The use of ultrafast lasers …