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Contrast Sensitivity and Visual Acuity Among the Elderly
Contrast Sensitivity and Visual Acuity among the Elderly THESIS Presented in Partial Fulfillment of the Requirements for the Degree Master of Science in the Graduate School of The Ohio State University By Mawada Osman Graduate Program in Vision Science The Ohio State University 2020 Master's Examination Committee: Angela M. Brown, PhD, Advisor Bradley E. Dougherty, OD, PhD Heidi A. Wagner, OD, MPH Copyright by Mawada Osman 2020 Abstract Purpose: To establish the clinical utility and strengthen the validity of the Ohio Contrast Cards (OCC), expand the use of the OCC in a healthy elderly population, and form a baseline dataset of patients to be compared to patients with dementia. Method: Participants ages 65 and over (N = 51) were recruited from the Ohio State University Primary Vision Care (PVC). We assessed the visual function of each patient using four visual tests which include: OCC, Pelli-Robson Chart (PR), Teller Acuity Cards (TAC) and Clear Chart. The contrast sensitivity tests (OCC and PR) were assessed twice, once by each tester. The PR contrast levels were also evaluated at two different distances 1 meter and 3 meters (0.50 meter if visual acuity worse than 6.0 cy/cm). Cognitive abilities were evaluated using the 6-Item Cognitive Impairment Test (6-CIT). Results: A significant effect of test was revealed (p < 0.005), in favor of OCC, yielding consistently higher average LogCS scores than PR, average difference of 0.412 LogCS. The PR and OCC revealed similar repeatability with 95% LoA of ± 0.28 log units and 95% LoA of ± 0.27 log units, respectively. -
Visual Performance of Scleral Lenses and Their Impact on Quality of Life In
A RQUIVOS B RASILEIROS DE ORIGINAL ARTICLE Visual performance of scleral lenses and their impact on quality of life in patients with irregular corneas Desempenho visual das lentes esclerais e seu impacto na qualidade de vida de pacientes com córneas irregulares Dilay Ozek1, Ozlem Evren Kemer1, Pinar Altiaylik2 1. Department of Ophthalmology, Ankara Numune Education and Research Hospital, Ankara, Turkey. 2. Department of Ophthalmology, Ufuk University Faculty of Medicine, Ankara, Turkey. ABSTRACT | Purpose: We aimed to evaluate the visual quality CCS with scleral contact lenses were 0.97 ± 0.12 (0.30-1.65), 1.16 performance of scleral contact lenses in patients with kerato- ± 0.51 (0.30-1.80), and 1.51 ± 0.25 (0.90-1.80), respectively. conus, pellucid marginal degeneration, and post-keratoplasty Significantly higher contrast sensitivity levels were recorded astigmatism, and their impact on quality of life. Methods: with scleral contact lenses compared with those recorded with We included 40 patients (58 eyes) with keratoconus, pellucid uncorrected contrast sensitivity and spectacle-corrected contrast marginal degeneration, and post-keratoplasty astigmatism who sensitivity (p<0.05). We found the National Eye Institute Visual were examined between October 2014 and June 2017 and Functioning Questionnaire overall score for patients with scleral fitted with scleral contact lenses in this study. Before fitting contact lens treatment to be significantly higher compared with scleral contact lenses, we noted refraction, uncorrected dis- that for patients with uncorrected sight (p<0.05). Conclusion: tance visual acuity, spectacle-corrected distance visual acuity, Scleral contact lenses are an effective alternative visual correction uncorrected contrast sensitivity, and spectacle-corrected contrast method for keratoconus, pellucid marginal degeneration, and sensitivity. -
Higher-Order Wavefront Aberration and Letter-Contrast Sensitivity In
Eye (2008) 22, 1488–1492 & 2008 Macmillan Publishers Limited All rights reserved 0950-222X/08 $32.00 www.nature.com/eye 1 1 2 2 CLINICAL STUDY Higher-order C Okamoto , F Okamoto , T Samejima , K Miyata and T Oshika1 wavefront aberration and letter-contrast sensitivity in keratoconus Abstract Keywords: keratoconus; wavefront aberration; higher-order aberration; contrast sensitivity; Aims To evaluate the relation between letter-contrast sensitivity higher-order aberration of the eye and contrast sensitivity function in eyes with keratoconus. Methods In 22 eyes of 14 patients with Introduction keratoconus (age 30.578.4 years, means7SD) and 26 eyes of 13 normal controls (age Keratoconus is a chronic, non-inflammatory 29.276.7 years), ocular higher-order wavefront disease of the cornea associated with aberration for a 6-mm pupil was measured progressive thinning and anterior protrusion of with the Hartmann-Schack aberrometer the central cornea.1,2 Irregular astigmatism is (KR-9000 PW, Topcon). The root mean square often the first and most apparent clinical finding (RMS) of third- and fourth-order Zernike in keratoconus, and this is evidenced by a coefficients was used to represent higher-order distortion of the corneal image as noted with aberrations. The letter-contrast sensitivity was the placido disc, retinoscope, keratometer, examined using the CSV-1000LV contrast chart keratoscope, and computerized (Vector Vision). videokeratograph. Previous studies using Results In the keratoconus group, the videokeratography have quantitatively 1 Department of letter-contrast sensitivity showed significant demonstrated that corneal irregular Ophthalmology, Institute of correlation with third-order (Spearman’s astigmatism is significantly greater in eyes with Clinical Medicine, University correlation coefficient ¼À0.736, 0.001) 3–6 of Tsukuba, Ibaraki, Japan r Po keratoconus than in normal eyes. -
Fact Sheet: Refractive Errors
Fact Sheet: Refractive Errors More than 11 million Americans have common vision problems that can be corrected with the use of prescriptive eyewear such as glasses or contact lenses.1 These conditions are known as refractive errors and they occur when the eye doesn’t correctly bend, or ―refract,‖ light as it enters the eye. Common refractive errors include the following: o Nearsightedness (also called myopia)—A condition where objects up close appear clearly, while objects far away appear blurry. With nearsightedness, light comes to focus in front of the retina instead of on the retina. o Farsightedness (also called hyperopia)—A common type of refractive error where distant objects may be seen more clearly than objects that are near. However, people experience farsightedness differently. Some people may not notice any problems with their vision, especially when they are young. For people with significant farsightedness, vision can be blurry for objects at any distance, near or far. o Astigmatism—A condition in which the eye does not focus light evenly onto the retina, the light-sensitive tissue at the back of the eye. This can cause images to appear blurry and stretched out. o Presbyopia—An age-related condition in which the ability to focus up close becomes more difficult. As the eye ages, the lens can no longer change shape enough to allow the eye to focus close objects clearly. Refractive errors are one of the most common—and correctable—causes of visual impairment in the United States. According to a recent study led by the National Eye Institute (NEI), approximately half of all American adults don’t have the 20/20 vision physicians consider optimal due to refractive errors.2 Women experience refractive error more frequently than men: Twenty-six percent more women aged 12 and older have uncorrected visual impairment due to refractive error compared with men aged 12 and older. -
Contrast Sensitivity and Visual Acuity in Low-Vision Students Thesis
Contrast Sensitivity and Visual Acuity in Low-Vision Students Thesis Presented in Partial Fulfillment of the Requirements for the Degree Master of Science in the Graduate School of The Ohio State University By Steve Murimi Mathenge Njeru, BS Graduate Program in Vision Science The Ohio State University 2020 Thesis Committee Angela M. Brown, PhD, Advisor Bradley E. Dougherty, OD, PhD Deyue Yu, PhD Copyrighted by Steve Murimi Mathenge Njeru 2020 Abstract 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. -
Contrast Gain in the Brain After (Green) Adapting to High Contrasts
Neuron 476 Rozin, P. (1982). Percept. Psychophys. 31, 397–401. Small, D.M., Voss, J., Mak, Y.E., Simmons, K.B., Parrish, T., and Gitelman, D. (2004). J. Neurophysiol. 92, 1892–1903. Small, D.M., Gerber, J.C., Mak, Y.E., and Hummel, T. (2005). Neuron 47, this issue, 593–605. von Békésy, G. (1964). J. Appl. Physiol. 19, 369–373. Wilson, D.A. (1997). J. Neurophysiol. 78, 160–169. Wilson, D.A., and Sullivan, R.M. (1999). Physiol. Behav. 66, 41–44. DOI 10.1016/j.neuron.2005.08.002 Figure 1. Example Contrast Response Functions Before (Blue) and Contrast Gain in the Brain After (Green) Adapting to High Contrasts Human sensory systems have the remarkable ability in the human visual system by using a clever method of adjusting sensitivity to the surrounding environ- that measured both increases and decreases in fMRI ment. In this issue of Neuron, Gardner and colleagues responses around a mean level of contrast. They used fMRI to show how the visual system shifts its showed that, after prolonged exposure to high con- sensitivity to contrast. This process may be helpful trasts, the “dynamic range” of the contrast response for keeping the appearance of contrast constant function in early cortical visual areas shifted from across a range of spatial frequencies. something like the blue curve in Figure 1 rightward to the green curve. This process of “contrast gain” was We’ve all had the experience of being temporarily originally found in electrophysiological studies in cats blinded when walking out of a movie theater into bright (Ohzawa et al., 1985), but this is the first evidence of it sunlight. -
Contrast Sensitivity and Acuity Relationship in Strabismic and Anisometropic Amblyopia
Br J Ophthalmol: first published as 10.1136/bjo.72.1.44 on 1 January 1988. Downloaded from British Journal of Ophthalmology, 1988, 72, 44-49 Contrast sensitivity and acuity relationship in strabismic and anisometropic amblyopia M ABRAHAMSSON AND J SJOSTRAND From the Department of Ophthalmology, University of Goteborg, Sahlgren's Hospital S-413 45 Goteborg, Sweden SUMMARY The contrast sensitivity function (CSF) and visual acuity were determined in children and adults with unilateral amblyopia due to strabismus or anisometropia with central fixation. The preschool children were examined repeatedly during occlusion treatment. All amblyopes had CSF deficits. The CSF was characterised by its peak value (the maximal sensitivity, Smax, and the spatial frequency at which Smax occurs, Frmax) calculated by a single peak least-square regression method. The two amblyopic groups showed discrepancies in relationship of both Smax and Frmax versus visual acuity both initially and during treatment. The strabismic cases had a more marked visual acuity deficit in relation to the contrast sensitivity losses, whereas these parameters are affected similarly in anisometropic amblyopes. The relationship between recovery of visual acuity and CSF during the initial month of occlusion treatment was of prognostic significance for the outcome of visual acuity improvement. copyright. Amblyopia is defined as an optically uncorrectable receives an input with deprived form and contour. loss of vision, usually monocular, without demon- There is no evidence that a strabismic eye receives a strable pathology in the posterior pole of the eye. blurred image, whereas several studies indicate that This condition develops in early childhood and it abnormal binocular interaction is present in http://bjo.bmj.com/ affects up to 5% of the population. -
Visual Impairment 101: What Do Administrators Need to Know?
Visual Impairment 101: What do Administrators Need to Know? Stephanie Walker, ESC Region 11 Mary Shore, TSBVI Outreach Visual Impairment 101 What do administrators need to know? Presented by: Stephanie Walker, M.Ed. Lead for the State Leadership Services for the Blind and Visually Impaired (SLSBVI) Network Mary Shore, COMS Professional Preperation Coordinator TSBVI Outreach Handouts and Additional Resources Texas School for the Blind and Visually Impaired - Administrator’s Toolbox Statewide Leadership Services for the Blind and Visually Impaired Simulation Activities What is a visual impairment? §300.8 (c)(13) Visual impairment including blindness means an impairment in vision that, even with correction, adversely affects a child’s educational performance. The term includes both partial sight and blindness. §89.1040 (c)(12) (A) A student with a visual impairment is one who has been determined to meet the criteria for visual impairment as stated in 34 CFR, §300.8(c)(13). The visual loss should be stated in exact measures of visual field and corrected visual acuity at a distance and at close range in each eye in a report by a licensed ophthalmologist or optometrist. The report should also include prognosis whenever possible. If exact measures cannot be obtained, the eye specialist must so state and provide best estimates. What types of vision does this include? Legally Blind Central vision acuity in the better eye of 20/200 or worse after the best correction possible, or a field of vision of 20 degrees or less. Low Vision/Partial sight Visual acuity better than 20/200 after correction in the better eye. -
Analysis of Three Genes in Leber Congenital Amaurosis in Indonesian Patients
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Vision Research 43 (2003) 3087–3093 www.elsevier.com/locate/visres Analysis of three genes in Leber congenital amaurosis in Indonesian patients Rita S. Sitorus a,b,*, Birgit Lorenz a, Markus N. Preising a a Department of Paediatric Ophthalmology, Strabismology and Ophthalmogenetics, Klinikum, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany b Department of Ophthalmology, School of Medicine, University of Indonesia, Salemba 6, Jakarta 10430, Indonesia Received 23 June 2003 Abstract Purpose. To assess the frequency, the pattern of disease causing mutations, and phenotypic variations in patients with Leber congenital amaurosis (LCA) from Indonesia. Patients and methods. Twenty-one unrelated index cases with a clinical diagnosis of LCA were screened for mutations in the coding sequence of RetGC1, RPE65 and AIPL1 gene with single strand conformation polymorphism analysis followed by direct sequencing and restriction enzyme digestion. Results. Four novel disease causing mutations were identified: Three in the RPE65 gene (106del9bp, G32V and Y435C) in two of 21 index cases and one in the AIPL1 (K14E). Two of them were homozygous and one was compound-heterozygous. No disease causing mutation was identified in RetGC1. Conclusions. The four novel disease causing mutations identified in this study confirmed the diagnosis of LCA which has not been recognized before in Indonesia. The frequency of RPE65 mutations was 9.5%; and of AIPL1 mutations 4.8%. This was in general accordance with previous studies reported from other countries. Unlike in those studies, no disease causing RetGC1 mutations could be identified in our patients. -
Factors Influencing Contrast Sensitivity Function in Eyes With
Journal of Clinical Medicine Article Factors Influencing Contrast Sensitivity Function in Eyes with Mild Cataract Kazutaka Kamiya 1,*, Fusako Fujimura 1, Takushi Kawamorita 1, Wakako Ando 2, Yoshihiko Iida 2 and Nobuyuki Shoji 2 1 Visual Physiology, School of Allied Health Sciences, Kitasato University, Kanagawa 2520373, Japan; [email protected] (F.F.); [email protected] (T.K.) 2 Department of Ophthalmology, School of Medicine, Kitasato University, Kanagawa 2520374, Japan; [email protected] (W.A.); [email protected] (Y.I.); [email protected] (N.S.) * Correspondence: [email protected]; Tel.: +81-42-778-8464; Fax: +81-42-778-2357 Abstract: This study was aimed to evaluate the relationship between the area under the log contrast sensitivity function (AULCSF) and several optical factors in eyes suffering mild cataract. We enrolled 71 eyes of 71 patients (mean age, 71.4 ± 10.7 (standard deviation) years) with cataract formation who were under surgical consultation. We determined the area under the log contrast sensitivity function (AULCSF) using a contrast sensitivity unit (VCTS-6500, Vistech). We utilized single and multiple regression analyses to investigate the relevant factors in such eyes. The mean AULSCF was 1.06 ± 0.16 (0.62 to 1.38). Explanatory variables relevant to the AULCSF were, in order of influence, logMAR best spectacle-corrected visual acuity (BSCVA) (p < 0.001, partial regression coefficient B = −0.372), and log(s) (p = 0.023, B = −0.032) (adjusted R2 = 0.402). We found no significant association with other variables such as age, gender, uncorrected visual acuity, nuclear sclerosis grade, or ocular HOAs. -
Frequency of Low Vision Patient and Their Causes Presenting in Madinah Teaching Hospital, Pakistan
Advances in Ophthalmology & Visual System Research Article Open Access Frequency of low vision patient and their causes presenting in Madinah Teaching Hospital, Pakistan Abstract Volume 9 Issue 6 - 2019 Aim: The aim of our study to determine the frequency of low vision patient and their causes presenting in Madinah Teaching Hospital. Fatima Iqbal,1 Iqra Khalil,1 Hafiza Ayesha Khalil,2 Mariam Sadiq,3 Hafiza Azka Noor,3 Methods: 400 patients were screened in the duration of five month from JAN to MAY Mawra Zahid 2019.80 subjects were taken as a low vision patient according to WHO, whose visual 1 acuity was less than 6/18 with correction. The main causes of low vision were observed Lecturer in School of Optometry, University of Faisalabad, Pakistan high refractive errors, retinitis pigmentosa, cataract, glaucoma and diabetic retinopathy all 2Optometrist, Fred Hollow Foundation, Pakistan patients presenting in ophthalmology department with either gender and age ranging from 3Optometrist, LRBT Toba Tek Singh, Pakistan 10-80 years. Uncooperative and mentally retarded persons were excluded in our study. 4Demonstrator, University of Lahore, Pakistan After complete history, we examined the all individual’s visual acuity with log-mar chart, color vision with ishihara and contrast sensitivity with Pelli-robson chart. Data was entered Correspondence: Fatima Iqbal, Lecturer in School of in to SPSS latest version and analyzed by descriptive analysis. Optometry, University of Faisalabad, Pakistan, Tel 03315538865, Email [email protected] Results: -
Chapter 10 Phase Contrast
Chapter 10 Phase Contrast Chapter 10 Phase Contrast © C. Robert Bagnell, Jr., Ph.D., 2012 Phase contrast makes living, unstained microscopic structures visible. Normally the difference in refractive index between a living microscopic structure and its surrounding environment is so small that the structure refracts very little light. Light is, however, diffracted by the specimen. Diffracted light is, on average, slowed down by 1/4 of a wavelength relative to undiffracted light. Undiffracted light is referred to as direct light. In the absence of any color contrast resulting from differential absorption, contrast can be created from the interference of diffracted and direct light. Phase contrast is a method of enhancing this interference. Types of Specimens for Phase Contrast Phase contrast is especially useful for living biological specimens. Today, cell cultures are a primary specimen for phase contrast. Phase contrast is useful for specimens that produce very little refraction; that is, their refractive index is not much different from their surrounding medium. Phase is also useful for specimens that possess little or no color of their own and which have not been artificially colored. In addition to cell and organ cultures, such specimens include bacteria, aquatic invertebrates, blood, and other body fluids. Historical Background of Phase Contrast Frits Zernike, a physicist at the University of Gröningen, Holland, discovered the phase principle in 1932. He described its use in microscopy in 1935. He won the Nobel Prize in physics in 1953 for this work. Zernike separated direct light from the specimen from diffracted light from the specimen by use of a special disk in the condenser.