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Full-Text Articles in Medicine and Health Sciences

Adaptation To A Simulated Central Scotoma With Visual Search Tasks, Dave Walsh Jan 2012

Adaptation To A Simulated Central Scotoma With Visual Search Tasks, Dave Walsh

All ETDs from UAB

This study characterized the perceptual and oculomotor adaptation to a simulated central scotoma in normally-sighted subjects and characterized the effects of two different scotoma profiles on the adaptation process. Twelve normally-sighted subjects, 6 for each type of scotoma profile, prac-ticed a search task (finding an "O" target among "C" distracters) for 11 blocks (162 trials per block). Search reaction time (RT) and eye movement data were collected. A head-mounted eye tracker was used to simulate two 10 deg circular central scotomas (CS), one with a sharp change from seeing to unseeing (S-CS) and the other with a gradual transition (G-CS). …


Electrophysiological Investigation Of Rabbit Retinal Ganglion Cells, Przemyslaw Nowak Jan 2012

Electrophysiological Investigation Of Rabbit Retinal Ganglion Cells, Przemyslaw Nowak

All ETDs from UAB

The retina is the first stage of the visual system, responsible for transducing light into the neural signal and for subsequent processing of this signal before sending it to the higher visual centers in the brain. The output to the higher visual centers is mediated by retinal ganglion cells, which not only relay the signal, but also substantially contribute to its processing. Depending on what computations they perform, they are subdivided into different types. These cells have been extensively studied in various spices, one prominent example being the rabbit. In rabbits, one characteristic type comprises On-Off directionally selective retinal ganglion …


The Effect Of A Topical Ocular Preparation On Performance Of Simulated Driving In Cases Of Symptomatic Dry Eye, Chandra Venise Mickles Jan 2012

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 …


Schizophrenia And Vergence Eye Movements, Mark S. Bolding Jan 2012

Schizophrenia And Vergence Eye Movements, Mark S. Bolding

All ETDs from UAB

Background: Compared to healthy controls (HC), patients with schizophrenia (SZ) have lower smooth pursuit gain and have been reported as having a higher prevalence of convergence insufficiency. To date, however, there have been no reports on vergence tracking gain in such patients. Therefore, we investigated both static and dynamic vergence behavior in healthy controls and patients with schizophrenia. Methods: Eye movements were recorded in multiple tasks including antisaccades, triangular waveform smooth pursuit at multiple frequencies, and triangular waveform vergence tracking of a real target at multiple frequencies. Eye position data were collected at 500 Hz using a binocular video eye …


Localization Of Proteins Involved In Trafficking In Frog And Mouse Retina, Amie Marsh Jan 2012

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.


Differential Expression Of Proteins In Keratoconus: Potential Role Of Human Antigen R (Hur) In Regulation Of Ss-Actin Gene, Roy Joseph Jan 2012

Differential Expression Of Proteins In Keratoconus: Potential Role Of Human Antigen R (Hur) In Regulation Of Ss-Actin Gene, Roy Joseph

All ETDs from UAB

DIFFERENTIAL EXPRESSION OF PROTEINS IN KERATOCONUS: POTENTIAL ROLE OF HUMAN ANTIGEN R (HuR) IN REGULATION OF ß-ACTIN ROY JOSEPH VISION SCIENCES ABSTRACT Keratoconus (KC) is a condition of unknown cause in which the cornea assumes a conical shape as a result of non-inflammatory thinning of the corneal stroma. The disease progresses at a variable speed with corneal thinning inducing irregular astigmatism, myopia, and corneal protrusion. Contact lenses, and ultimately keratoplasty, are often required to restore vision. Despite intensive investigations into the pathogenesis of KC, the exact cause of the disease is presently poorly understood. Keratoconus apparently arises due to number …


The Effect Of Acetylcholine Receptor Activation On The Response Properties Of Retinal Ganglion Cells, Ye Long Jan 2012

The Effect Of Acetylcholine Receptor Activation On The Response Properties Of Retinal Ganglion Cells, Ye Long

All ETDs from UAB

Acetylcholine (ACh) is the first identified neurotransmitter and acts in areas including the peripheral nervous system (PNS) and the central nervous system (CNS). The effects of ACh are mediated by nicotinic and muscarinic acetylcholine receptors (AChRs), both of which are extensively distributed in CNS, including the retina. The expression and distribution of nicotinic AChRs (nAChRs) and muscarinic AChRs (mAChRs) have been studied with RT-PCR, western blot, and immunohistochemical techniques in the retinas of different species (Kaneda et al., 1995; Keyser et al., 2000; Yamada et al., 2003; Strang et al., 2005; Dmitrieva et al., 2007; Liu et al., 2009; Strang …


The Effect Of Structured Background On Smooth Pursuit With Real And Simulated Central Scotoma, Thomas Keith Jan 2012

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 …