Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 18 of 18
Full-Text Articles in Medicine and Health Sciences
Diagnostic Electrophysiology Of The Eye, Brooke Nicole Conner-Tsang
Diagnostic Electrophysiology Of The Eye, Brooke Nicole Conner-Tsang
All ETDs from UAB
Aging and age-related changes in the brain are known to parallel functional and anatomical changes in the eye, especially in certain degenerative diseases. This study explores the potential of combining ERG, specifically the Pattern Electroretinogram (PERG), which has a black and white checkerboard pattern, and OCT tests to monitor retinal ganglion cell health. We compared ERG and OCT findings from ten normal females, ages ranging from 18 to 30 years old to ascertain if ganglion cell layer volume is a reliable indicator of ganglion cell function as measured by ERG. Our results from these healthy subjects will serve as prelude …
Role Of Developmental Protein, Nudc, In The Retina, Skyler Boehm
Role Of Developmental Protein, Nudc, In The Retina, Skyler Boehm
All ETDs from UAB
Rod photoreceptors are the most prominent light sensitive cell in the retina of most mammals. The outer segments of photoreceptors contain the cellular machinery necessary for phototransduction to occur. The process of generating the phototransduction components occurs in the inner segment before being trafficked to the outer segment. These processes are highly regulated and require many different trafficking proteins and chaperones. The developmental protein nuclear distribution gene C (nudC) was found to be present in the photoreceptor, but its function is yet to be determined. Here we confirm that nudC is present in the retina and necessary in the photoreceptors. …
Integration Of Cone Photoreceptor Signals In Macaque Lgn Neurons, Paul B. Brown
Integration Of Cone Photoreceptor Signals In Macaque Lgn Neurons, Paul B. Brown
All ETDs from UAB
Despite advances in the understanding of the primate visual system, much is yet to be learned about the way light signals sum to create our perception of the world. This is especially true at the simplest level of visual processing—the summation of two individual cone photoreceptor signals. How such signals combine to create visual perception has not been assessed in vivo. We used an adaptive optics scanning laser ophthalmoscope (AOSLO) to deliver binarized noise movies to identified groups of cones within the receptive fields of neurons in the macaque lateral geniculate nucleus (LGN). Recordings of neural action potentials within the …
A Microfocal Effect In Photoreceptor Light Capture, Vasantha Kumari Kanukuntla
A Microfocal Effect In Photoreceptor Light Capture, Vasantha Kumari Kanukuntla
All ETDs from UAB
In human eyes, accomodation brings light rays into focus on the retina in order to achieve a clear images. The plane of best focus within the depth of the retina is thought to be within the photoreceptor layer, but pinpointing the exact focal position axially has not been determined. With help of adaptive optics aberration correction and its ability to have microscopic control of a retinal stimulus, we explored how sensitive human subjects are to defocus on the micron scale. We found that focal position can be reliably judged within 0.02 D, which is equivalent to about 6 microns in …
A Comparison Between Number And Letter Acuities Among Patients, Sarah Berry
A Comparison Between Number And Letter Acuities Among Patients, Sarah Berry
All ETDs from UAB
ABSTRACT Purpose: Previous studies have shown that there is an association between visual acuity and Alzheimers’ disease. Untreated visual problems may contribute to cognitive impairment and more progressive cognitive decline. This study investigates the association of chart design, specifically comparing charts using letters versus numbers, to accuracy and repeatability among patients with dementia. Methods: 23 English-speaking subjects diagnosed with moderate to advanced levels of dementia were recruited from two local Birmingham nursing homes. Visual acuities were measured in a randomly selected eye and timed from six different charts: Back-illuminated ETDRS chart with letters, Back-illuminated ETDRS chart with numbers, HOTV cards …
Conjunctival Gene Expression And Tear Biomarkers In Atopic And Non-Atopic Keratoconus Patients Relative To Matching Controls, Erika Marie Morrow
Conjunctival Gene Expression And Tear Biomarkers In Atopic And Non-Atopic Keratoconus Patients Relative To Matching Controls, Erika Marie Morrow
All ETDs from UAB
Purpose: The aim of this study was to adapt conjunctival impression cytology (CIC) and RNA isolation to genetic analysis of the conjunctival surface of keratoconus (KC) patients with (AKC) and without atopic disease (AD) and with normal contact lens wearers (NCL). If RNA quantity and quality was sufficient, full transcriptome analysis would be conducted using RNA-Seq, rather than the more limited microarray approach. Methods: CIC samples were the ocular surface of 30 participants from four groups: 1) KC, 2) AKC, 3) AD, and 4) NCL. Several extraction and purification methods were investigated, including density gradient centrifugation, precipitation, conventional pelleting, and …
Within Session Repeatability Of The Tear Lab Osmolarity Test And Correlation With Other Clinical Tests For Dry Eye, Pearl Shin
All ETDs from UAB
WITHIN SESSION REPEATABILITY OF THE TEAR LAB OSMOLARITY TEST AND CORRELATION WITH OTHER CLINICAL TESTS FOR DRY EYE PEARL SHIN DEPARTMENT OF VISION SCIENCES ABSTRACT Background The human tear film consists of three primary layers that work in conjunction to provide protection and nutrition to the cornea. When a layer is disrupted, the entire tear film loses its integrity and fails to function normally. Dry eye is the most common cause of tear film disruption. Among several methods to characterize dry eye is measurement of tear osmolarity. The TearLab Osmometer is commonly used clinically for this purpose. Previous studies in …
Studies Of The Effect Of Nicotine On Color Vision In Color Deficient Humans, Warren Gwynn
Studies Of The Effect Of Nicotine On Color Vision In Color Deficient Humans, Warren Gwynn
All ETDs from UAB
Previous research showed that oral nicotine use in non-smoking color normal individuals significantly improved color discrimination scores on the F-M 100 and both white and red increment thresholds of the Red Test. Our research sought to determine if similar results could be found when oral nicotine was administered to color deficient individuals. Ten color deficient individuals were first screened with both the HRR and Nagel Anomaloscope. Next, the F-M 100 and Red Test were performed before and after chewing nicotine gum (four mg). Subjects were introduced to testing procedures in one visit; a second visit, at least 24 hours later, …
Validation Of A Cytometric Bead-Based Immunoassay For Tear Interleukin 8 And Interferon Gamma Inducible Protein 10, My-Tho Karin Tran
Validation Of A Cytometric Bead-Based Immunoassay For Tear Interleukin 8 And Interferon Gamma Inducible Protein 10, My-Tho Karin Tran
All ETDs from UAB
ABSTRACT Background Interleukin 8 (IL-8) and Interferon gamma inducible protein 10 (IP-10) are pro-inflammatory chemokines that may play key antagonistic roles in regulating corneal immune privilege and angiogenesis prevention. Some groups have reported that tear levels of IL-8 and IP-10 measured by multiplexed antibody-based assay are artifact prone and therefore unreliable, leading to their under-utilization as ocular surface disease and dry eye biomarkers. The current study compares tear levels of IL-8 and IP-10 measured by multiplexed cytometric bead-based assay (CBA) with single analyte ELISA assay. Mass spectrometry, a non-antibody based method, was also used to obtain confirmation of tear levels. …
Comparison Of Low Abundance Biomarker Levels In Capillary-Collected Non-Stimulated Tears And Washout Tears Of Aqueous-Deficient And Normal Patients, Nicole Guyette
All ETDs from UAB
Purpose: For patients suffering from aqueous-deficient dry eye, non-stimulated (NS) tear collection can be challenging and time-consuming. Adding a small volume of sterile saline to the eye allows a "washout" (WO) tear collection that takes considerably less time. The primary goal of this project was to determine if WO tear collection is a viable alternative to NS tears for comparing the levels of common ocular surface biomarkers in patients with and without aqueous-deficient dry eye (AD). Stimulated (Stim) tears were also investigated as a second possible alternative to NS tears. Methods: Two studies were conducted, tear cytokine levels being measured …
Comparisons Between Electrophysiologic Assessments Of Visual Function And Histological Findings Of Cone Photoreceptors In Light-Damaged Albino Rats, Molly Clark
All ETDs from UAB
The purpose of this project was to investigate the etiology of decreased cone-driven vision in the light damage model of retinal degenerations. Experimental albino rats underwent moderate, low-intensity light damage for 10 days. Electroretinography was utilized to assess physiologic function of the rod- and cone-driven retinal function in the experimental and control (sibling) rats. Immunohistochemical staining for cone arrestin antibody identified cone photoreceptors, allowing quantification of cone density and comparison to the decline in functional vision. In this experiment the light-damaged rats showed decreased rod- and cone-driven function with partial recovery of responses 30 days later. Outer nuclear layer thickness …
The Effect Of Structured Background On Smooth Pursuit With Real And Simulated Central Scotoma, Thomas Keith
The Effect Of Structured Background On Smooth Pursuit With Real And Simulated Central Scotoma, Thomas Keith
All ETDs from UAB
The purpose of the study was to better understand the role of the fovea in smooth pursuit eye movements in human subjects. The research entailed a systematical study of a previously unstudied condition where the foveal inputs of both the background and the pursuit target were eliminated through simulation but the anatomic fovea was intact; and a comprehensive study of smooth pursuit eye movements of human subjects with real central scotoma. Ten normally sighted subjects (NS) and three central scotoma subjects (CS) were asked to visually pursuit a 0.87o yellow dot moving along either a horizontal or a vertical trajectory …
Localization Of Proteins Involved In Trafficking In Frog And Mouse Retina, Amie Marsh
Localization Of Proteins Involved In Trafficking In Frog And Mouse Retina, Amie Marsh
All ETDs from UAB
The connecting cilium serves as the major route for protein transport from the inner to outer segment of photoreceptor cells. The hypothesis that all Congenital Stationary Night Blindness (CSNB) rhodopsin mutants travel properly to the rod outer segment in Xenopus laevis will be tested by preparing transgenic X. laevis expressing a rhodopsin mutation found in human CSNB, A295V. In addition, probing for the existence of potential proteins involved in regulating rhodopsin trafficking and monitoring their localization will contribute to a better understanding of the underlying pathway of intracellular photoreceptor trafficking.
The Effect Of A Topical Ocular Preparation On Performance Of Simulated Driving In Cases Of Symptomatic Dry Eye, Chandra Venise Mickles
The Effect Of A Topical Ocular Preparation On Performance Of Simulated Driving In Cases Of Symptomatic Dry Eye, Chandra Venise Mickles
All ETDs from UAB
Dry eye is a common complaint of millions of people worldwide with a significant impact on quality of life. In particular, it could have a significant impact on vision-related activities of daily living such as driving. The purpose of this investigation was to determine if 30 days of active topical dry eye treatment (Systane® Balance, Alcon Laboratories; Ft. Worth, TX) has an impact on the simulated night-time driving performance in mild or moderate dry eye compared to a topical saline (Sensitive Eyes®, Bausch & Lomb; Rochester NY). Dry eye symptoms and signs were also assessed to corroborate our findings. Forty …
Tear Component Interference In Bead-Based Biomarker Assays Using Magnetic Beads, Larezia Denise Williams
Tear Component Interference In Bead-Based Biomarker Assays Using Magnetic Beads, Larezia Denise Williams
All ETDs from UAB
Cytokines in tears can be biomarkers for ocular inflammation in dry eye subjects. Multiplex bead-based assays measure the concentration of multiple cytokines in a single tear sample. Bio-Rad® polystyrene bead-based assay kits have provided acceptable results for tear samples in this lab. Recently, Bio-Rad decided to replace polystyrene beads with magnetic beads. In earlier experiments in this laboratory, magnetic bead-based as-says did not produce results equivalent to polystyrene bead-based assays. The purpose of this investigation was to modify the magnetic bead-based tear cytokine assay to produce equivalent results to those obtained with the polystyrene bead-based assay. The modifications included running …
Measuring Aniseikonia Using Scattering Filters To Simulate Cataract, Jason Anthony Wilson
Measuring Aniseikonia Using Scattering Filters To Simulate Cataract, Jason Anthony Wilson
All ETDs from UAB
MEASURING ANISEIKONIA USING SCATTERING FILTERS TO SIMULATE CATARACT JASON WILSON DEPARTMENT OF VISION SCIENCE ABSTRACT The relationship between anisometropia and aniseikonia (ANK) is not well understood. Ametropic cataract patients provide a unique opportunity to study this relationship after undergoing emmetropizing lens extraction. Because light scatter may affect ANK measurement in cataract patients, its effect should also be evaluated. The Basic Aniseikonia Test (BAT) was evaluated using afocal size lenses to produce specific changes in retinal height. Several light scattering devices were then evaluated to determine which produced effects most similar to cataract. Contrast sensitivity and visual acuity (VA) losses were …
Visually Impaired Caregivers: Perspectives From Patient Focus Groups, Bethany Surrey Martinez
Visually Impaired Caregivers: Perspectives From Patient Focus Groups, Bethany Surrey Martinez
All ETDs from UAB
Purpose: We typically think of those with severe visual impairment as having to receive care or assistance for tasks in everyday living. However, with the aging of the population, more persons who are severely visually impaired are now caring for a spouse of significant other. Very little is known about visually impaired (VI) caregivers. Thus, the purpose of this qualitative study is to learn more about this vulnerable population of VI caregivers. Methods: Focus groups and one-on-one interviews were conducted with English speaking adults who were legally blind (U.S. definition) and served as informal caregiver of an adult family member. …
Stem Cell Markers In The Posterior Limbus And Cornea, Sara L. Mcgowan
Stem Cell Markers In The Posterior Limbus And Cornea, Sara L. Mcgowan
All ETDs from UAB
The corneal endothelium is a layer of cells in the cornea that is responsible for maintaining the clear state of the cornea. Corneal endothelial cells may be induced to divide, but do not regularly divide in the normal cornea of a human beyond the age of twenty. Some studies have suggested that a stem cell population may reside in the pe-ripheral corneal endothelium or in the posterior limbus. Important molecular markers of stem cells are nestin which is expressed in neural crest stem cells; alkaline phosphatase is active in stem cells and not in differentiated cells; telomerase is a marker …