Master of Science, The Ohio State University, 2007, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 2008, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 2024, Vision Science

Purpose: The purpose of this project is to determine whether the difference between the stimulus targets of The Ohio Contrast Cards (OCC) and the Mayer-Kran Double Happy cards (DH) affect the measured contrast sensitivity of low vision patients. Methods: We recruited 54 patients from the OSU College of Optometry Low Vision and Bioptic Driving Clinics for this study. After obtaining consent, two examiners tested each participant to determine his/her Weber contrast sensitivity. The first tester used either the Ohio Contrast Cards or the Double Happy Cards in addition to the Pelli-Robson Chart, after which the second tester used whichever card test was not used by the first tester. The order of testers and card tests was randomized across participants. The card tests were used in a testing protocol that was similar to the protocol of the Teller Acuity Cards. After contrast sensitivity testing was completed, a vision-related quality of life (QoL) survey was administered to the participants. Participants were compensated $10 for their time. The study was designed (alpha = 0.05, beta = 0.80) to reveal differences of 0.15 Log10 units or greater between tests. Bootstrapped analysis of median performance was used to analyze results between contrast sensitivity tests. Stepwise linear regression was used to analyze correlation between contrast sensitivity, visual acuity, and quality of life. Results: Within-patient analysis revealed no statistically significant difference between the OCC and DH card tests (difference = 0.013 Log units, 95% range: -0.044—0.071). A significant difference in patient performance was found when comparing the OCC or the DH to the PR (0.23 Log10 and 0.22 Log10 units respectively). Contrast sensitivity showed a stronger correlation to quality of life compared to visual acuity, with results of the OCC having the strongest association of all tests performed. Conclusions: Regardless of the difference in target stimulus, the Ohio Contrast Cards and (open full item for complete abstract)

Committee: Angela Brown (Advisor); Bradley Dougherty (Advisor); Deyue Yu (Committee Member); Mawada Osman (Committee Member) Subjects: Ophthalmology

Master of Arts (MA), Bowling Green State University, 2024, Psychology

Shared reward pathways in the brain unveil the potential for the development of dependence on a variety of substances, including commonly recognized drugs of abuse and, more insidiously, sugar. Sugar overconsumption has been associated with compulsivity and impulsivity repetitive behaviors which are predictors of later substance abuse. Furthermore, previous research has shown that rats can develop symptoms mirroring addiction such as binging, craving, tolerance, and withdrawal in response to sugar alone. Motivation research has indicated that impaired reward relativity is a key component of vulnerability to addiction. The ability of an animal to discriminate between differing levels of rewards for the amount of work exerted to receive that reward may predict later addictive behavior to a variety of substances. This thesis examined the appetitive and consummatory behavior of non-food restricted female Wistar rats in self-administration tasks of sucrose and ethanol solutions. Relative reward effects were evaluated by using trials that differ in time of access to the reward (20s vs 10s vs 5s). The results suggest that non-food restricted Wistar rats show discrimination between substance and length of trial, as well as some sensitivity to intra-session alterations in ethanol reward. They exhibit diminished sensitivity to sucrose in consumption and lick rate. Behavioral measures like consumption and nosepoke latency had some predictive potential in regard to behavioral response to ethanol. The incentive contrast paradigm used in this project allows a closer examination of the motivational processes shared by alcohol and sugar that could result in addiction. Using natural reward sensitivity to predict future addiction could aid significantly in preventing and treating substance use disorders.

Committee: Howard Casey Cromwell Ph.D. (Committee Chair); Melissa Keith Ph.D. (Committee Member); Jari Willing Ph.D. (Committee Member) Subjects: Animals; Neurosciences; Psychology

Master of Science, The Ohio State University, 2024, Vision Science

Purpose: This project was designed to measure the repeatability of the Ohio Contrast Cards (OCCs) in a pediatric population across examiners, and before and after cycloplegia. Methods: We measured contrast sensitivity (CS) using the OCCs on 44 children (ages 3-11) who attended their routine, dilated eye exams. There were 38 normally sighted children and seven amblyopes. CS was measured twice, by different examiners, before and after dilation with cycloplegic agents (1% Tropicamide, 1% Cyclopentolate, or both). The pre-dilation tests were performed monocularly through any habitual refractive correction. One of the post-dilation tests was performed monocularly without any refractive correction to evaluate the effect of blur on measured CS. Results: CS measured with the OCCs was similar across examiners before dilation (95% Bland-Altman Limits of Agreement (LoA) +/-0.211). An Analysis of Variance (ANOVA) showed no significant effect of the examiner performing the test (p=0.561) or the order in which the tests were performed (p=0.924). CS was also similar within examiners before and after dilation (r=0.573, p<0.001; LoA +/-0.244). A second ANOVA showed that the post-dilation CS values did not depend significantly on eye color (p=0.429), dilating agent (p=0.562), or dilation time (p=0.216). There was also no association between CS and total blur due to uncorrected cycloplegic refractive error (r=-0.099, p=0.518). Conclusion: The OCCs show good inter-examiner repeatability in this population. The OCCs are robust to moderate amounts of blur, so they may be used after dilation as a time-saving examination measure.

Committee: Angela Brown (Advisor) Subjects: Ophthalmology; Optics

Master of Science, The Ohio State University, 2020, Vision Science

Purpose: This study primarily compared the test-retest reliability of the Pelli-Robson chart (PR) and Ohio Contrast Cards (OCC) amongst testers. The secondary goal of this study was to examine the impact on contrast sensitivity if the testing distance for the Pelli-Robson chart were to be changed. An additional goal was to evaluate the relationship between visual acuity (VA) and contrast sensitivity (CS) when using letter-based charts and grating cards. Methods: Thirty low-vision students were tested, ranging from 7-20 years old. Each student was tested with both VA and CS tests in randomized order, which included: the Bailey-Lovie chart (BL), Pelli-Robson chart, Teller Acuity Cards (TAC), and Ohio Contrast Cards. Each student repeated both the PR chart and OCC in separate rooms, but neither the BL chart nor TAC was repeated. The PR chart was also tested at closer testing distance, based on the student's logMAR acuity from the BL chart. For the letter charts, a letter-by-letter scoring method was used. For grating cards, these were both scored as preferential looking tests. Results: The Limits of Agreement for the OCC and PR chart were +/- 0.451 and +/- 0.536, respectively. There was no statistically significant difference between tester or order of testers for the PR chart and OCC. Using the PR chart at a closer distance yielded an improvement in contrast threshold performance when compared to the standard testing distance. Students performed better on grating cards than letter charts, regardless of VA testing or CS testing. Conclusions: The Ohio Contrast Cards are a promising diagnostic tool for evaluating CS on low-vision patients and other patients who cannot be tested using letter-based charts. Clinicians using the Pelli-Robson chart for low-vision patients should consider testing closer than the standard testing distance.

Committee: Angela Brown PhD (Advisor); Bradley Dougherty OD, PhD (Committee Member); Deyue Yu PhD (Committee Member) Subjects: Health Care; Ophthalmology

Master of Science, The Ohio State University, 2018, Vision Science

Purpose: The use of bioptic telescopic spectacles (BTS) to obtain licensure for driving is currently legal in over 42 states, yet questions remain about performance and safety. The effect of BTS on sign identification distance is unknown. Previous studies reported worse ratings for lane position and steering steadiness in bioptic drivers, but were unable to report differences attributable to BTS use due to safety concerns with on-road testing. This study utilizes a driving simulator to compare sign identification performance with and without BTS use, and to compare bioptic and normally-sighted drivers. Velocity, lane position, and lane deviations are also examined. Additionally, self-ratings of quality of driving, avoidance, dependence, and driving space are examined. Methods: Bioptic drivers and controls were recruited from The Ohio State University College of Optometry. Visual acuity, contrast sensitivity, and visual field were assessed. The study was completed in a six-degree-of-freedom driving simulator equipped with a 260° curved front screen simulator with side mirror LCD displays and a screen seen through the rear-view mirror. Subjects completed a 32,000 meter straight four-lane highway course with light traffic and a speed limit of 45 mph. The main task was to press a button on the steering wheel whenever a target city name or route number road sign was confidently identified amongst distractor signs. This task was completed twice, once using the BTS and once without. Paired t-tests were used to analyze differences in sign recognition distance, velocity, lane position and steering entropy. Differences in the number and duration of lane deviations were also examined. Results: Twelve bioptic drivers and six controls participated. Mean±SD bioptic driver age was 56±17 and 55±10 for controls. Mean logMAR VA OU for bioptic drivers was 0.80±0.17 (20/125) and mean log CS was 1.48±0.16. Mean VA with telescope was 0.21±0.10 (20/32). The mean sign identification d (open full item for complete abstract)

Committee: Bradley Dougherty OD, PhD (Advisor); Thomas Raasch OD, PhD (Committee Member); Aaron Zimmerman OD, MS (Committee Member) Subjects: Ophthalmology; Optics

Master of Science, The Ohio State University, 2016, Vision Science

Purpose: For an individual not eligible for a regular driver's license due to central visual impairment, 43 states allow for licensure with the aid of bioptic telescope spectacles (BTS). BTS consist of a small telescope lens mounted in the upper portion of a distance prescription lens. There is limited information regarding the driving exposure and road safety of bioptic drivers. The purpose of this study was to determine whether vision or demographic factors predict mileage driven in bioptic drivers and to determine a per mile motor vehicle collisions (MVC) rate. Methods: Data on visual acuity (logMAR charts), contrast sensitivity (Pelli-Robson or Mars charts), age, sex, and previous driving experience were collected retrospectively from clinic records at the Ohio State University College of Optometry. MVC data was collected from the Bureau of Motor Vehicles database. A modified version of the Driving Habits Questionnaire (Owsley et al., 1999) was administered in person or by mail, and subjects were asked to estimate their yearly mileage. Spearman correlation and Mann-Whitney U tests were performed to determine predictors of driving exposure. Per mile MVC rate was calculated and used to compared to calculated MVC rates in the general population. Results: 73 licensed Ohio bioptic drivers (48 male) were included. Mean (±SD) age was 51±16 years. Mean (min, max) binocular logMAR visual acuity was 0.66 (1.20, 0.18), or approximately 20/100. Median contrast sensitivity was 1.57 (1.00, 1.95). Reported annual mileage ranged from 100 to 90,000 miles per year, with a mean of 9,746. Age, gender, and previous (non-bioptic) driving experience were not significantly associated with estimated annual mileage. Visual acuity was inversely related to reported mileage (Spearman correlation = –0.286, P = 0.015). Contrast sensitivity was directly related to reported mileage (Spearman correlation = 0.308, P = 0.009). Glare acuity was inversely related to reported mileage (Spearman (open full item for complete abstract)

Committee: Bradley Dougherty OD, PhD (Advisor); Roanne Flom OD (Committee Member); Dean VanNasdale OD, PhD (Committee Member) Subjects: Ophthalmology; Public Health

Master of Science, The Ohio State University, 2014, Vision Science

A new test of contrast sensitivity (CS), the Stripe Card Contrast Sensitivity (SCCS) test, could serve as a simple and efficient means for estimating the maximum contrast sensitivity value of a given patient without having to use multiple spatial frequency gratings, and without knowing the spatial frequency at which maximum sensitivity occurs. This test could be useful for a wide range of patients with various levels of visual acuity (VA), ages, and diagnoses. We measured VA [Bailey-Lovie (BL), Teller Acuity Cards (TAC)] and CS [Pelli-Robson (PR), SCCS, Berkeley Discs (BD)] in counterbalanced order with subjects at the Ohio State School for the Blind (OSSB). Thus, we tested VA and CS using letter charts (B-L, P-R), grating cards (TAC, SCCS) and a chart with shapes (BD). Vision-related quality of life (QoL) surveys [The Impact of Visual Impairment in Children (IVI_C) and Low Vision Prasad Functional Vision Questionnaire (LVP-FVQ)] were used following vision testing. Additionally, we obtained Michigan Orientation & Mobility (O&M) Severity Rating Scale (OMSRS) severity of need scores for some participants. Testing was performed over a two-year period for 51 participants at OSSB. We have organized our work into three experiments: Experiment I was performed in the 2012-13 school year and included 27 participants who were tested monocularly using the patient's preferred eye. The following year, we returned for repeat testing of 11 participants from the first year (“Experiment IIa”) and additional testing of 24 new participants (“Experiment IIb”). Those assessments were performed on each eye monocularly (where possible) rather than just with the preferred eye. QoL and O&M results were obtained during both years of testing and are detailed in Experiment III. Vision tests on the better eyes correlated positively and significantly with one another, except for a non-significant correlation between the B-L and SCCS. The IVI_C correlated significantly with all vision tests, (open full item for complete abstract)

Committee: Angela Brown PhD (Advisor); Roanne Flom OD (Committee Member); Thomas Raasch OD, PhD (Committee Member) Subjects: Health Care; Ophthalmology

Doctor of Philosophy, The Ohio State University, 2009, Vision Science

The reduction in visual resolution due to visual blur is a common experience, especially when individuals requiring eyewear remove their spectacles or contact lenses. However,studies have shown that when one looks continually at a visual acuity chart through blur, the smallest letters that one can read at first are not as small as the letters that one can read several minutes later. This improvement in sensitivity following a period of exposure to blur is referred to as blur adaptation. The purpose of this dissertation is to evaluate the temporal and spatial aspects of blur adaptation. Ten subjects were enrolled in each of the three visual acuity studies. The temporal characteristics were assessed, firstly, by varying the initial blur exposure duration (0min, 1min, 5min and 15min exposures) to a natural scene image. Visual acuity measured using a short 1.5min and a long 10min computer-based letter presentations, using Bailey-Lovie optotypes, was the outcome measure. Secondly, the influence of varying letter exposure durations was tested using three letter presentation times (2sec, 4sec and 15sec exposure per letter). The spatial characteristics of adaptation were assessed by adapting to a blurred natural scene, visual acuity chart, and different sets of alphabets presented in large and small sizes. A fourth study, carried out on one subject, looked at the effects of blur adaptation on the contrast sensitivity function. It was seen that visual acuity was not influenced by the four initial blur exposure durations to the natural scene. Also, adaptation to stimuli with various spatial characteristics like a natural scene, acuity chart, and letters of varying sizes did not result in different acuity scores. However, there was a significant influence of test letter presentation duration. Acuity was better with long acuity presentation times compared to short presentation times. The acuity score from the 15sec per letter presentation was better than those from 2sec per let (open full item for complete abstract)

Committee: Donald Mutti OD, PhD (Advisor); Delwin Lindsey PhD (Committee Member); Thomas Raasch OD, PhD (Committee Member); Mathew Allen VetMB, PhD (Committee Member) Subjects: Optics

Doctor of Philosophy, Miami University, 2009, Psychology

Stimuli that are placed outside of the classic receptive field of a visual cortical cell can modify that cell's response to stimuli within the field, as part of the cell's modulatory receptive field. In addition, masks that are superimposed on a target can modify response to the target, even when the mask and stimuli are separated widely enough in spatial characteristics (orientation and spatial frequency) to stimulate separate channels. The nature of these cross-channel interactions has been modeled in a variety of ways. Here we explored an alternative method of investigating cross-channel interactions that may lead to simpler models. Specifically, we measured a change in response as a function of increasing contrast of the stimulus when a mask is added, either surrounding or superimposed on the stimulus. The results of the experiment indicate that the model we apply is useful in explaining performance across a wide variety of contexts. While some of the data agrees with the physiological literature and some does not, the contributions of two parameters (response gain and contrast gain) can be adjusted in each condition to account for behavioral response data.

Committee: Lynn A Olzak PhD (Committee Chair); Robin D Thomas PhD (Committee Member); Allan J Pantle PhD (Committee Member); Vincent A Billock PhD (Committee Member); Gregory J Reese PhD (Committee Member); Elisabeth Schussler PhD (Committee Member) Subjects: Behaviorial Sciences

Doctor of Philosophy, The Ohio State University, 2013, Vision Science

Bioptic telescopic spectacles (BTS) allow people with vision impairment to obtain driving licensure even when their visual acuity does not meet normal state standards. BTS are spectacles with a small telescope implanted in one or both of the lenses. The telescope is used for brief periods during driving to spot distant targets such as road signs and traffic signals. The study described in this dissertation examines visual and demographic associations among obtaining a bioptic driving license, training and road testing results, and motor vehicle collisions in patients with low vision. The study also compares the collision rate of bioptic drivers to that of a control group of non-bioptic drivers matched on age and sex. A retrospective study of medical records was completed for patients examined for entry into the Ohio bioptic driving program at the College of Optometry at The Ohio State University over a five year period. Data were collected on visual factors, documented driver training, licensure testing results, and post-licensure driving record. No significant associations were found among visual and demographic factors and obtaining licensure after an initial vision examination. Several factors were significantly associated with the amount of training documented for candidates for licensure, including age and previous non-bioptic driving experience. The amount of training documented was associated with road testing results, but not with driving safety after licensure. Previous driving experience was also significantly associated with occurrence of motor vehicle collisions (MVC) in bioptic drivers, with drivers without previous experience having approximately 2.5 times as many collisions per year of licensure than those with previous experience. Other significant associations with MVC in bioptic drivers included age and the number of non-collision related convictions. Nystagmus was independently associated with MVC, but no other patient visual factors w (open full item for complete abstract)

Committee: Thomas Raasch (Advisor) Subjects: Biomedical Research; Health Sciences; Ophthalmology; Optics; Public Health; Public Policy; Transportation