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PubMedDate not supplied

After the examination: care of low vision patients beyond ocular services.

1. A low vision program should assist patients by assessing their living conditions, daily routines, and personal interests; providing practical suggestions to enhance safety and independence; advising them on availability of programs, and assisting in emotional and psychological rehabilitation of patients and families. 2. Within the ophthalmic profession, a bridge is needed between the importance of the psychosocial aspects of patient care and the importance of the medical and scientific research community in their quest for advanced technology and treatment. 3. It is important not to instill a false sense of hope that vision will be restored. Excellent prognostic signs for social adjustment and independence begin with a realistic acceptance of blindness.

Female↗
PubMed1994

The design of a zoom stand magnifier--a new low vision device.

A new stand magnifier has been designed for low vision patients and developed into a working instrument. This zoom magnifier has two ergonomic advantages over the currently available single lens magnifiers: it stays in focus (zooms) as the power is changed and it has a longer working space to allow both reading and writing with the same magnifier. This two-lens zoom magnifier contains a stationary plus lens and a movable minus lens. Using a symmetry condition, first order equations are presented and solved for the two lens powers. A family of three zoom magnifiers was designed--low, medium, and high power--each with a conveniently positioned sharp image with a 2-fold range of power and magnification. The equivalent viewing powers of the units (for a +2.50 D add) range from 6 to 23 D. The working spaces are approximately double that of comparable power single lens stand magnifiers.

Equipment Design↗
PubMed1991

Low vision aids--is our service cost effective?

A questionnaire and telephone survey was carried out on a Scottish population of patients with impaired vision, in order to ascertain the proportion of patients who gain benefit from Low Vision Aids (LVA) and to determine the number of LVAs which are retained but unused. One third of the patients who answered the questionnaire never use their LVAs, and one half were not satisfied with the service provided. A cost analysis indicated that approximately (pounds) 8,000 worth of LVAs are neither used nor returned each year to a single LVA service. The patients' ages, diagnoses, and visual acuities were related to the compliance rate. It appears that increasing age and decreasing visual acuity may be factors which decrease compliance. However none of the factors analysed could be used as a reliable predictor of patient satisfaction or of eventual benefit. Other health services which provide intensive training in the use of LVAs reportedly achieve a higher level of compliance. We conclude that our present service could probably be improved by the employment of additional staff specifically trained to teach patients how to make best use of the LVAs provided.

Adolescent↗
PubMed1997

Veterans' use of low vision devices for reading.

BACKGROUND: This report presents the results of a 2-year study of veterans' use of low vision devices (LVDs) which were prescribed and dispensed through the Blind Rehabilitation Centers (BRCs) and Visual Impairment Centers to Optimize Remaining Sight (VICTORS) of the Department of Veterans Affairs. METHODS: Two-hundred veterans using 740 LVDs were surveyed by telephone 12 to 24 months after the prescription/dispensing of the devices. Reliability (test-retest) and validity (content, criterion-related, and construct) were established for the survey. Primary analysis of the data was accomplished through tabular presentations. Because most devices were used for reading, an exploratory data analysis was completed to further investigate successful use of LVDs for this task. Relationships of 21 variables with a definition of highly successful use, use and nonuse of LVDs for reading were evaluated. RESULTS: Only visual acuity provided a statistically significant predictor of use of LVDs for reading. LVDs in the lowest visual acuity grouping tend to be used either highly successfully, or fall into the nonuse category. The highly successful LVDs are primarily video magnifiers; the nonused LVDs tended to be spectacle magnifiers. CONCLUSIONS: This population is using devices extensively for reading, reporting frequencies of use of several times per day.

Health Surveys↗
PubMed1981

Use of the Frostig Figure Ground in evaluation of adults with low vision.

The Frostig Figure Ground Test can be a valuable tool in the evaluation of adult low-vision patients. It is easily administered and can give valuable information about the patient's functioning. It provides an observable assessment of the individual sensory-perceptual capacities and has the further advantage of requiring the use of eye-hand coordination. Correlations of performance in this test with other data were analyzed for 79 low-vision patients. The test appears to provide some predictive information about the patient's reading performance, accounting for one-third of the variability of reading speed.

Eye Diseases↗
PubMed1997

Magnitude and causes of blindness and low vision in Anambra State of Nigeria (results of 1992 point prevalence survey).

A survey to determine the prevalence and causes of blindness in Anambra State of Nigeria was conducted. The aim was to provide baseline data for the planning, implementation and evaluation of both the state's and the National Programme for Prevention of Blindness. A multistage cluster random sampling technique was used. The World Health Organization/Prevention of Blindness (WHO/PBL) Eye Examination Record Form was used. The WHOs definitions of blindness and low vision were adopted for the analysis. The prevalence of blindness in the state is estimated to be 0.33% +/- 0.27%. Visual acuity of from 3/60 to less than 6/60 has a prevalence of 0.41% +/- 0.30% while visual acuity of from 6/60 to less than 6/18 has a prevalence of 0.67% +/- 0.39. There are equal numbers of blind males as females, although the prevalence among males is 0.44% +/- 0.26% while among females it is 0.24% +/- 0.15%. Most of the blind are above 50 y of age with prevalence of blindness in this age group being 2.62% +/- 1.31% (3.27% +/- 2.1% for males and 2.02% +/- 1.58% for females). Cataract caused most of the blindness (70.59%), followed by glaucoma (17.65%). Macular degeneration is becoming important (5.88%) while obvious infective causes are rare. Errors of refraction are important public eye health care problems. Methods of tackling the cataract problem (both backlog and incident), and other eye health needs within the primary eye/health care are recommended. The need to extend refraction services to the rural areas is emphasized.

Adolescent↗
PubMed1995

Low vision rehabilitation for a patient with a traumatic brain injury.

The client described in this article had undergone intensive rehabilitation for physical and cognitive deficits that resulted from an anoxic encephalopathy. Her recovery was good in all areas except visual functioning. Her reading and writing deficits were initially thought to result from visual-perceptual problems. A low vision evaluation identified the deficits as resulting from a macular visual field loss. Warren (1993) has proposed that an intact visual field is one of the basic components of vision that must be present before higher visual processing can occur. Until the macular perimetry was performed on this client, the extent of her central field loss was unknown, and the treatment that focused on the higher level visual processing was unsuccessful. The low vision program targeted the central field loss as the probable cause for her difficulties and an effective treatment protocol was established. The client was instructed regarding the nature of her visual field deficit and was trained in methods to compensate for this deficit. Although she has not returned to work as of this writing because of financial disincentives, the training resulted in a measurable and functional improvement in the client's ability to read continuous print text, a task she had not performed in 4 years, and in her ability to perform all writing tasks needed for daily living.

Adult↗
PubMed1995

Living with low vision: a personal and professional perspective.

Unlike most readers of this special issue, I have been both a consumer and provider of rehabilitation services. A retinal hemorrhage that occurred when I was in my late twenties signaled the beginning of delayed-onset retinopathy of prematurity--a condition that has been further complicated since that time. In this article, I offer a glimpse of what living with low vision is like by describing activities in my own life and accommodations I have made. My hope is that therapists will learn more about the realities of living with low vision and will seek our additional information that they will incorporate into their practice.

Activities of Daily Living↗
PubMed2001

Use of a contact lens telescopic system in low vision patients.

This study was designed to evaluate the effectiveness of a contact lens telescopic system in patients diagnosed with low vision. Fifteen white patients (mean age 60.7 years) with visual acuity between 20/60 and 20/400 (mean 20/245) were evaluated using first a conventional telescope and subsequently a contact lens telescope (CLT). Evaluation parameters were visual acuity, amplitude of visual field, and patients' satisfaction with the systems. The mean final visual acuity attained with both systems was 20/105. No differences in visual acuity between the two systems were detected. However, the visual field was significantly different with each system. Mean visual field with the conventional telescope was 22 degrees, whereas with the CLT it was 52.1 degrees. This corresponds to a reduction of 78.2% in the field of view with the conventional telescope and of 49.5% with the CLT. Therefore, the CLT was found to provide a field of view that is 136% as great as the one provided by the conventional telescope. Younger patients are specially enthusiastic about the CLT because of its improved cosmetic appearance and visual field as compared to traditional telescopes. Aged patients tend to have more difficulty in accepting and using contact lenses daily.

Adolescent↗
PubMed1997

National survey of the impact of low vision device use among veterans.

BACKGROUND: This report presents the results of a 2-year study of veterans' use of low vision devices (LVDs) which were prescribed and dispensed through he Blind Rehabilitation Centers (BRCs) and Visual Impairment Centers to Optimize Remaining Sight (VICTORS) of the Department of Veterans Affairs. METHODS: Two-hundred veterans using 740 LVDs were surveyed by telephone 12 to 24 months after the prescription/dispensing of the devices. Reliability (test-retest) and validity (content, criterion-related, and construct) were established for the survey. Primary analysis of the data was accomplished through tabular presentations. Factor analyses were used to describe prescription and use patterns. RESULTS: Most (85.4%) of the devices were still in use. Having a helper in the home was a demographic variable related to continued use. Neither age, acuity, nor etiology were related to continued use. Strong prescription and use patterns emerged. Most veterans reported receiving > 20 h of training and > 20 h of practice in the use of their LVDs. CONCLUSIONS: Most veterans who receive LVDs through the service delivery system of the Department of Veterans Affairs appear to use them for a wide variety of daily tasks and reported that they obtain a great deal of benefit from their use.

Adult↗
PubMedDate not supplied

Evidence-based guidelines on the referral of visually impaired persons to low vision services.

PURPOSE: One to two percent of the population in the Western world is visually impaired or blind. For most of these people there is no curative therapy. Therefore, the Dutch Ophthalmic Society has taken the initiative to develop an evidence-based guideline for the referral of visually impaired persons to low vision services. METHODS: A systematic literature search was performed in the Embase (1991-2001) and Medline (1966-2003) databases. Literature was searched for definitions of visual impairment, for physician-patient communication, and for outcome of interventions for visually impaired persons. Results of the articles that were selected were summarized and rated according to the level of evidence. Other considerations such as the current organization of rehabilitation for visually impaired persons in the Netherlands were also taken into account. RESULTS: The World Health Organization criteria were slightly adapted in order to include all people who experience problems with reading and other daily life activities due to visual impairment. A large number of recommendations were devised. Among these is that the complete diagnosis should be communicated to the patient and that a second appointment should be offered in which the diagnosis and potential treatment options are discussed again. Another recommendation is that in general visually impaired adults eligible for referral should be referred for the provision of low vision aids and that patients with complex problems or extensive rehabilitative demand should be referred to a rehabilitation center. CONCLUSIONS: This article presents a summary of the first European evidence-based guideline for the referral of visually impaired persons.

Adult↗
PubMed1997

[Description of the prismation method in the rehabilitation of low visions of macular origin].

GOALS: This work aimed at presenting an original rehabilitation method based on the prismation available for patients with organic lesions of the macula. We report results obtained in our first series of patients. MATERIAL AND METHODS: The treatment was given to 14 patients, 7 women and 7 men, aged from 68 to 92 years, with an average age of 81.64, followed in "Low Vision" consultation, and suffering from bilateral macular diseases. All the patients with age-related macular degeneration developed retinal correspondences. They all received a bilateral prismation over their old correction. The orientation of the prisms taking into account the eccentric fixations. The criteria chosen for surveillance were binocular subjective and objective acuity, contrast sensitivity and vision of colours. RESULTS: For all the patients concerned, the method led to an immediate subjective improvement of the visual function. Tolerance to optical support was improved. The patients recovered better self-sufficiency in their daily life. The objective binocular for VA was improved by at least one line for 92.86% of the patients, by at least 2 lines for 42.85% and by 3 lines for 7.14%. The binocular contrast sensitivity was better for all the patients. Regarding the vision of binocular colours, the examination performance time was improved for all the patients. CONCLUSIONS: Prismation allows optimal use of the corresponding eccentric fixation areas. It appears as an interesting new therapeutic method for patients with macular-related low vision. It is complementary to rehabilitation treatment of such patients.

Aged↗
PubMed1988

Low vision and the elderly patient.

This paper describes special considerations and approaches that are necessary in optometric care of the elderly patient with low vision. Emphasis is placed on case history and presentation of treatment recommendations. Procedures for the systematic assessment of vision are described and there is a discussion of the kinds of low vision aids most commonly prescribed for the elderly.

Aged↗
PubMed2006

The prevalence of low vision and blindness in Canada.

PURPOSE: The purpose of this study was to ascertain the prevalence and primary causes of visual impairment in a representative Canadian population. METHODS: We reviewed a representative sample of patients who attended ophthalmologists' offices in a medium-sized Canadian city between 1996 and 2001 in order to estimate the prevalence of visual impairment. Demographic data, visual diagnoses, best-corrected visual acuities (BCVA), and visual field information were recorded. Visual status was categorized based on accepted World Health Organization (WHO) and North American criteria. Population data were obtained from the Canadian census. RESULTS: The prevalence of low vision and blindness in our population was 35.6 and 3.8 per 10 000 individuals, according to the WHO classification, and 71.2 and 23.6 per 10 000 individuals, using the North American definition. Among individuals with some vision loss (vision worse than 20/40), cataract and visual pathway disease were the most common causes, together accounting for 40% of visual impairment. Age-related macular degeneration and other retinal diseases were the next most common causes of vision loss. Diabetic retinopathy and glaucoma were less frequently encountered as causes of visual impairment. CONCLUSION: The overall prevalence of low vision and blindness in Canada are in keeping with data from large population-based studies from other developed nations. Cataract, visual pathway disease, and macular degeneration are the leading causes of visual impairment. These results are important for enhancing our understanding of the scope of vision health in Canada and may direct future health planning and cost-utilization research.

Adolescent↗
PubMed1995

Adaptation to macular scotomas in persons with low vision.

Persons with scotomas in their central 20 degrees of vision often do not notice these blind spots within their visual field and have visual performance difficulties far exceeding what would be expected from standard vision tests. Before persons with macular scotomas can be assisted to optimally use their remaining vision for a better quality of life, more must be known about how the visual system adapts to a macular scotoma. Important issues include spatial and temporal characteristics of perceptual completion and metamorphopsia, development of preferred retinal loci for fixation and visual search, and dynamics of the preferred retinal locus development in terms of the changes in the eye movement system. With a full understanding of the visual system's adaptation to macular scotomas, new low vision devices and training techniques can be proposed to promote independence in activities of daily living for the person with low vision.

Activities of Daily Living↗
PubMed1986

Visual rehabilitation of patients with advanced diabetic retinopathy. A follow-up study at the Low Vision Clinic, Department of Ophthalmology, University of Linköping.

Seventy-nine patients with advanced diabetic retinopathy were subjected to a full range of low vision rehabilitation measures and followed for an average of 3.6 years at the Low Vision Clinic. They were provided with high power optical aids, followed by educational training in the use of such aids and of residual vision, including the utilization of peripheral retina by means of eccentric viewing technique in many cases (23%). Mean age was 52.7 years. Type I diabetes was diagnosed in 69 subjects and type II in 10 subjects. Proliferative retinopathy was present in 73 cases and background retinopathy in 6 cases. All subjects showed macular changes in varying degrees. (Another 36 patients participated in the first series of visits but could not be followed up, the main reason being that 31 of them died before follow-up. There were no major differences between the two groups regarding rehabilitation results.) The average power of the telescopes used for distance vision was 4.8 X, and the mean power of the aids used for reading and near vision, mainly increased near addition and hyperocular lenses, was 22.2 dioptres (5.6 X). The patients were also provided with aids for intermediate distance and for 'spot use'. The average number of series of visits was 2.7 and the number of 1 h training sessions 2.5 per series of visits. With aids and training, mean visual acuity improved from 0.17 to 0.73 on the first series of visits. After the last series of visits acuity was still as good as 0.64. Ability to read TV titles increased from 15.2% to 79.7% in the group and reached 64.6% after the last series of visits. The number of individuals able to read newspaper text increased from 1.3% to 97.5%. After the last series of visits the number was still as large as 86.1%. Of the individuals who had to stop working because of poor vision, 89% would have been able to return to work after rehabilitation. However, because of unemployment problems in the area, only 72% managed to return. It is quite obvious from the results that the presented methods, including high power aids and training sessions, are extremely successful in rehabilitation of patients with advanced diabetic retinopathy, provided that they have at least some residual vision. Dramatic improvements in visual performance were seen, allowing a life of much better quality than before.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1999

Characteristics of AMD patients with low vision receiving visual rehabilitation.

The purpose of this retrospective study done on 255 AMD patients evaluated at a low vision rehabilitation service was: 1) to describe the visual function characteristics (VFCs) of AMD patients presenting to visual rehabilitation, 2) to document changes in these VFCs between initial and follow-up rehabilitation visits, and 3) to investigate the relationship of the VFCs found at rehabilitation intake to the length of time between initial diagnosis and initial rehabilitation visit. Standard clinical testing (visual acuity and contrast sensitivity) as well as Scanning Laser Ophthalmoscope (SLO) visual function testing were performed to determine visual function including: 1) macular perimetry for scotoma boundary mapping and 2) PRL (preferred retinal locus) location and abilities in fixation, saccadic, and pursuit eye movements. The difference between the first and second visit VFCs were compared to the length of time between visits for 44 of the 255 patients returning for a second visit 0.5 to 4.5 years later. Finally, the initial date of AMD diagnosis was found for 51 of the 255 patients to analyze VFCs as a function of the time duration between diagnosis and the intake to the rehabilitation. Most VFCs had a wide range of results at initial intake to rehabilitation, while all patients had significant visual impairment by 24 months after initial diagnosis. The majority of low vision patients with AMD have bilateral central scotomas with the corresponding visual function and ADL problems that can often be overcome with visual rehabilitation.

Aged↗
PubMed2001

[Grading of light perception and hand movement utilizing a novel device called the low vision evaluator].

PURPOSE: There has been no device for grading very low visual function expressed as light perception or hand movement up to the present. It is necessary to evaluate even slight effects of modern and classical therapies during the follow-up period. The goal of this study was to invent a novel device for grading such low visual function. METHODS: Sixty-two patients with a visual acuity of counting fingers or worse due to various diseases were examined. The device, which we call the Low Vision Evaluator, has a pair of goggles equipped with two white light-emitting diodes. Nine variations of stimulus for light intensity (1, 10, 100 cd/m2 or 10, 100, 1,000 cd/m2) and duration (0.1, 0.3, 1 second) can be delivered in a random sequence. Patients were asked to push a button whenever they saw a stimulus. Response of patients to the stimuli was recorded. RESULTS AND CONCLUSIONS: The visual function of light perception and hand movement could be reproducibly assessed by this method. The method represents a valuable new tool for evaluating low visual function.

Adult↗