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At least 109 records · Page 6Linked to original sources
PubMed2006

Causes of low vision and blindness in adult Latinos: the Los Angeles Latino Eye Study.

OBJECTIVE: To describe the causes of low vision and blindness in a population-based sample of adult Latinos. DESIGN: Population-based cross-sectional study. PARTICIPANTS: Six thousand three hundred fifty-seven Latinos 40 years and older from 6 census tracts in Los Angeles, California. METHODS: Participants underwent a detailed ophthalmologic examination including measurement of best-corrected distance visual acuity using a standard Early Treatment for Diabetic Retinopathy Study protocol, a complete anterior and posterior segment evaluation by an ophthalmologist, Humphrey Visual field testing, and optic disc and fundus photography. Consensus diagnosis of independent investigators reviewing all patient data was used to determine the major causes of low vision and blindness in adult Latinos. MAIN OUTCOME MEASURES: Primary causes of vision loss in persons with low vision and blindness. RESULTS: The leading causes of low vision were cataract, diabetic retinopathy, and age-related macular degeneration, together accounting for approximately 82% of all persons with low vision. The primary causes of blindness were age-related macular degeneration, diabetic retinopathy, and myopic degeneration, accounting for 63% of the cases of blindness. CONCLUSIONS: Many of the leading causes of low vision and blindness in adult Latinos are potentially preventable and treatable diseases. Given the projected aging and growth in the Latino population, consideration needs to be given to the development of targeted early detection and treatment programs.

Adult↗
PubMed2004

Adjustable typography: an approach to enhancing low vision text accessibility.

Millions of people have low vision, a disability condition caused by uncorrectable or partially correctable disorders of the eye. The primary goal of low vision rehabilitation is increasing access to printed material. This paper describes how adjustable typography, a computer graphic approach to enhancing text accessibility, can play a role in this process, by allowing visually-impaired users to customize fonts to maximize legibility according to their own visual needs. Prototype software and initial testing of the concept is described. The results show that visually-impaired users tend to produce a variety of very distinct fonts, and that the adjustment process results in greatly enhanced legibility. But this initial testing has not yet demonstrated increases in legibility over and above the legibility of highly legible standard fonts such as Times New Roman.

Adult↗
PubMed1992

[The relationship between reading rehabilitation and visual functions in low vision].

Reading rehabilitation was done for 51 low vision patients who underwent tests of the contrast sensitivity function (CSF) and the visual field. The results showed that the recognized frequency of CSF was related to the reading capability. The CSF was useful in predicting the reading prognosis, and visual field impairment significantly affected the reading ability. The relationship between the reading rehabilitation and the visual functions was discussed.

Adolescent↗
PubMed1990

Visual characteristics of low vision children.

A retrospective survey of pediatric clinical files from the Kooyong Low Vision Clinic (LVC) showed that the major causes of low vision were congenital or inherited conditions and most children had 6/60 (20/200) or better distance acuities. A classroom evaluation of these children showed that overall, the clinically determined visual acuity corresponded with classroom performance. A high rate of use of prescribed low vision aids was found, and a reading evaluation on a standardized test showed poor performance with respect to reading speed and comprehension, but almost all the children had adequate reading accuracy. Considering the importance of reading in education, greater emphasis on reading evaluations in routine low vision examinations is recommended.

Adolescent↗
PubMed2002

[Satisfaction with low vision aids].

PURPOSE: To study satisfaction with the prescription of low vision aids (LVA) and to correlate LVA with eye disease and visual function one year after prescription. METHODS: A questionnaire was sent out to 576 patients who had received LVAs in 1998. We evaluated their subjective satisfaction with the LVA as well as with the whole examination in our low vision department and compared the kind of LVA with disease and visual acuity. In addition, we observed whether additional functional deterioration led to problems with the LVA. RESULTS: 301 questionnaires were returned (52 %). They reported on high satisfaction with the management and the LVA (> 90 %). 57 % used their optical LVAs more than 5 times daily mostly for reading and writing (74 % and 78 %, respectively). However, 20 patients were no longer able to read with their LVA due to decrease of function. When comparing the LVAs, most patients with age-related macular degeneration were supplied with magnifiers (30 %). Thirty percent of the patients supplied with CCTVs (43 %; visual acuity 0.02 to 0.3) used the CCTV daily. CONCLUSIONS: The majority of low vision patients is very satisfied with the prescription of LVAs and frequently uses these aids. The adequate LVA is a major factor improving the quality of life. However, due to the possibility of greater deterioration after the disease, follow-up examinations on a regular basis appears to be necessary. The early prescription of CCTVs often helps to preserve the reading ability and should therefore be kept in mind by the physician dealing with low vision patients.

Adolescent↗
PubMedDate not supplied

Blindness and low vision in adults in Ozoro, a rural community in Delta State, Nigeria.

BACKGROUND: The objective of this article is to determine the prevalence and causes of blindness and low vision in Ozoro, a rural town of Delta State in Nigeria, in order to provide baseline information for planning a prevention of blindness programme. METHODS: A cross sectional study using a stratified random sampling method was used to select the compounds. The five communities in the town formed the different sub-groups or strata. Visual acuity were recorded for all adults 40 years and older. Persons who had visual acuity less than 6/18 were further examined to determine the cause of low vision or blindness. The WHO definition of visual impairment according to visual acuity was used as criteria for classification. RESULTS: A total of 815 persons (coverage of 51.7%) were examined using a modified WHO PBL record of blindness form. The prevalence of blindness (VA < 3/60 in the better eye) for people of 40 years and above was 6.3% (95% CI, 4.6% to 8%) and low vision VA 6/24 to 3/60 in the better eye was 25.2%. The estimated prevalence of bilateral blindness for all ages was 1.3% and low vision was 5%. The rate of blindness and low vision increased with age being highest in subjects who were 60 years and above. The main causes of blindness and low vision were cataract, accounting for 60% of all bilateral blindness and 51.7% of all low vision. Other causes of blindness include, posterior segment diseases (11.7%). Glaucoma was presumed to be cause of blindness in 9.8% of cases; others were uncorrected aphakia 5.9%, and globe abnormalities 5.9%. Refractive error was the second major cause of low vision accounting for 22% of bilateral low vision. CONCLUSION: The magnitude of blindness and low vision in this oil rich Ozoro community in Delta State is high and majority are avoidable causes of blindness.

Adult↗
PubMed2002

Determining magnification for reading with low vision.

BACKGROUND: In the past, practitioners have used distance and/or near visual acuity (VA) to calculate required magnification for low vision aids. Magnification was usually under-estimated when compared with the final magnification prescribed. Recent studies have emphasised the importance of acuity reserve in determining the required magnification for optimum reading rate. Two different approaches have been proposed for the appropriate acuity reserve to use in calculating magnification. These are a fixed acuity reserve of 0.3 log unit or an individual determination of optimum acuity reserve. The aim of this study was to investigate the magnification and reading rates with low vision aids selected by the two methods. METHODS: Nineteen low vision subjects with age-related macular degeneration (AMD) who were experienced magnifier-users were recruited. Reading rates and near VA with low vision aids determined by the fixed and individual acuity reserve methods were compared with the same measures made with the subjects' own magnifiers. RESULTS: There were no significant differences in reading rate and near VA measured with low vision aids selected by either the fixed or individual acuity reserve methods or the subjects' own magnifiers. Reading rate with low vision aids was not significantly different from reading rate for large print with conventional near additions. Thus, for experienced users, magnifiers do not cause reduced reading rate. CONCLUSIONS: The fixed acuity reserve method is simple to apply as only near VA and print size of the target reading task are required. For the individual acuity reserve method, reading rates at different print sizes need to be measured. We recommend the use of a fixed acuity reserve (0.3 log unit) for the calculation of required magnification for low vision patients. If near VA or reading rate are not satisfactory with the magnification calculated by this method, individual assessment of required acuity reserve is necessary.

Aged↗
PubMed2003

Low vision and blindness in adults in Gurage Zone, central Ethiopia.

AIM: To determine the magnitude and causes of low vision and blindness in the Gurage zone, central Ethiopia. METHODS: A cross sectional study using a multistage cluster sampling technique was used to identify the study subjects. Visual acuity was recorded for all adults 40 years and older. Subjects who had a visual acuity of <6/18 were examined by an ophthalmologist to determine the cause of low vision or blindness. RESULTS: From the enumerated population, 2693 (90.8%) were examined. The prevalence of blindness (<3/60 better eye presenting vision) was 7.9% (95% CI 6.9 to 8.9) and of low vision (6/24-3/60 better eye presenting vision) was 12.1% (95% CI 10.9 to 13.3). Monocular blindness was recorded in 16.3% of the population. Blindness and low vision increased with age. The odds of low vision and blindness in women were 1.8 times that of the men. The leading causes of blindness were cataract (46.1%), trachoma (22.9%), and glaucoma (7.6%). While the prevalence of vision reducing cataract increased with age, the prevalence of trachoma related vision loss did not increase with age, suggesting that trichiasis related vision loss in this population might not be cumulative. CONCLUSION: The magnitude of low vision and blindness is high in this zone and requires urgent intervention, particularly for women. Further investigation of the pattern of vision loss, particularly as a result of trachomatous trichiasis, is warranted.

Adult↗
PubMed1989

Predictors of functional success in telescopic spectacle use by low vision patients.

Telescopic spectacles can theoretically improve function of low vision patients by enlarging retinal images. However, unintended head movement may produce sufficient instability of enlarged retinal images to negate the visual benefit. We investigated this phenomenon as a cause of failure in 38 low vision patients who had previously attempted use of telescopic spectacles. Patients underwent evaluation of the vestibulo-ocular reflex, visual-vestibulo-ocular reflex, head stability in the pitch and yaw axes, and sensitivity of magnified visual acuity to head motion. Although it was impossible to distinguish successful from unsuccessful telescopic spectacle users by means of clinical or historical data, multiple logistic regression analysis was used to derive a useful predictive function based on measurements of sensitivity of magnified vision to head motion, and head instability in the pitch axis. Predictive performance was found to be superior to conventional clinical judgement. These findings support the hypothesis that retinal image stability is important to functional vision, and suggest that head-stabilizing strategies may improve function with telescopic spectacles in certain low vision patients.

Adult↗
PubMed1986

NoIRs and low vision.

Records of three hundred and eighteen low vision patients from three low vision centers were reviewed to determine patient preferences for NoIR light filters based on ocular disease and visual acuity. Eighty-nine percent chose the #101 and #102 filters. Patients with dry macular degeneration, chronic open angle glaucoma, and retinitis pigmentosa showed a greater preference for the #101 NoIRs. When visual acuity dropped below 20/400, no patients selected the darker filters (#108 & #109).

Eye Diseases↗
PubMed2004

Developing an integrated paediatric low vision service.

A survey of usage of low vision aids (LVAs) by 56 children with visual impairment, who were attending mainstream schools in Wirral, was undertaken. A total of 25% of children owned an LVA and 5% were using these on a regular basis. These low levels of ownership and usage led to the development of a low vision service involving the collaboration of education and health care. This paper describes the development of that service, its elements and implementation. The results from the new service show that of the 29 children issued with an LVA, 82.7% are using them on a regular basis. Having an integrated service is shown to significantly improve LVA usage in the group of children seen so far. The service results are discussed with suggestions for future service development.

Adolescent↗
PubMedDate not supplied

Improving health care experiences of persons who are blind or have low vision: suggestions from focus groups.

Persons who are blind or have low vision face special challenges in obtaining care that is safe, effective, timely, and patient centered. To explore perceptions of care and recommendations for improvements, we conducted 8 interviews with experts and 2 focus groups with 19 persons, all of whom are blind or have low vision. Interviewees perceived that they confront special barriers to care because of being blind or having low vision. Barriers fell into 4 broad categories: basic respect, including concerns about physicians thinking they cannot participate fully in their own care; communication barriers, including difficulties interacting with physicians and office staff; physical access barriers, including difficulties getting to and around physicians' offices; and information barriers, including receiving written materials in inaccessible formats (eg, not in Braille, large print, or audiotape). Using common courtesy and individualized communication techniques, physicians and office staff could improve health care experiences of blind and low-vision patients.

Blindness↗
PubMed2006

Prevalence and causes of low vision and blindness in a Japanese adult population: the Tajimi Study.

OBJECTIVE: To determine the prevalence and causes of low vision and blindness in a Japanese adult population. DESIGN: Population-based cross-sectional study. PARTICIPANTS: Randomly selected residents (n = 3870) of Tajimi City, Japan, who were 40 years of age or older. METHODS: Of the 3021 study participants (78.1% of 3870 eligible persons), 2977 (76.9%) underwent a complete ophthalmologic examination including measurement of the best-corrected visual acuity (BCVA) with full subjective refraction using a Landolt ring chart at 5 m. Age- and gender-specific prevalence rates of low vision and blindness were estimated and causes were identified. MAIN OUTCOME MEASURES: Low vision and blindness were defined as BCVA in the better eye worse than 20/60 to a lower limit of 20/400 and worse than 20/400, respectively (World Health Organization [WHO] criteria) and worse than 20/40 but better than 20/200 and 20/200 or worse, respectively (United States criteria). RESULTS: The overall prevalence of blindness according to the WHO or U.S. criteria was 0.14% (n = 4; 95% confidence interval [CI], 0.06-0.32). The primary causes were optic atrophy, myopic macular degeneration, retinitis pigmentosa, and uveitis. The overall prevalence of low vision according to the WHO criteria was 0.39% (95% CI, 0.18%-0.60%) and according to the U.S. criteria was 0.98% (95% CI, 0.66%-1.30%), which was significantly greater in women and in the older half of the participants than in the younger half (P = 0.0079 and <0.0001, respectively). The leading causes of low vision in descending order were cataract followed by glaucoma, and those of monocular blindness were myopic macular degeneration, glaucoma, and trauma. CONCLUSIONS: The prevalence of low vision and blindness in Japanese adults was one of the lowest among those reported. The major causes of low vision were cataract and glaucoma, and the leading cause of monocular blindness was myopic macular degeneration.

Aged↗
PubMed1996

Iowa's pediatric low vision services.

BACKGROUND: Reports in the literature concerning the evaluation and low vision management of visually impaired children are limited, resulting in a lack of information about the characteristics and needs of this population. METHODS: A review was performed of 762 children evaluated over a 14-year period in a low vision clinic program coordinated by the Iowa Braille and Sight Saving School. RESULTS: The age, sex, ocular condition, best corrected visual acuity, habitual near point working distance, and optical devices recommended for use by these children were analyzed. CONCLUSIONS: Ongoing, comprehensive multidisciplinary low vision services are necessary to help children with visual impairments meet their educational, vocational and avocational needs. With ongoing low vision care unnecessary costs-such as those for large print material-can be avoided, therefore creating a significant savings to local or state educational services.

Adolescent↗
PubMed1998

Visual correlates of mobility in real world settings in older adults with low vision.

PURPOSE: To determine the effects of reducing light level from photopic to mesopic on performance of real world mobility tasks and how performance of these tasks relates to measures of visual sensory and perceptual function. METHODS: The visual functions, acuity, peak letter contrast sensitivity, visual field extent, glare disability, color confusion, motion sensitivity, spatio-temporal contrast sensitivity, scanning ability, and figure-ground discrimination were measured to determine their ability to predict mobility performance of visually impaired adults on indoor hallway and outdoor residential travel routes under photopic and mesopic lighting conditions. RESULTS: Time to complete routes and number of mobility incidents were significantly increased under mesopic conditions. Depending on the task, lighting conditions, and performance measure, predictive models consisting of 4 vision variables were able to account for 30 to 42% of the variance in overall performance. The two most important variables in these models were visual field extent and scanning ability, followed by color confusion, grating contrast sensitivity, or spatial resolution. CONCLUSIONS: Reducing illumination levels from photopic to mesopic has an adverse effect upon mobility in older visually impaired adults. The aspects of vision which best predict performance include measures of sensory and perceptual visual function. The results compare well with those obtained under controlled laboratory conditions.

Adaptation, Ocular↗