Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Vision, Low”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed2005

Vision-related quality of life in patients with bilateral severe age-related macular degeneration.

PURPOSE: To determine the quality of life (QOL) of patients with bilateral severe age-related macular degeneration (AMD) before macular translocation with 360 degrees peripheral retinectomy. DESIGN: Prospective, consecutive, noncomparative case series. METHODS: An observational study assessed vision-related and general health QOL using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) and the Medical Outcomes Study 12-item short form (SF-12) surveys, respectively. Mean QOL scores were correlated with patient age, duration of vision loss, and visual function. Mean QOL scores in study patients were compared with mean QOL scores in groups of patients with low vision, patients with AMD of varying severity, and reference populations. MAIN OUTCOME MEASURES: National Eye Institute VFQ-25 and SF-12 QOL scores. RESULTS: Seventy patients with a mean age of 76.4 years were studied. Mean distance visual acuity (VA) was 62.4 (Early Treatment Diabetic Retinopathy Study letters), mean near VA was 0.81 (logarithm of the minimum angle of resolution), and mean reading speed was 74.9 words per minute. Important NEI VFQ-25 quality of vision subscales (general vision, difficulty with distance tasks, difficulty with near tasks) and vision-specific subscales (dependency, role difficulties, mental health, social function limitations) tended to correlate negatively with increasing patient age and duration of vision loss, but correlated positively with better VA and reading speed. The mean QOL scores for these important quality of vision and vision-specific subscales were significantly worse than or similar to mean scores in patients with low vision, and significantly worse than scores in patients with AMD of varying severity and a reference population. The mean SF-12 physical composite score in study patients was similar to that seen in patients with AMD of varying severity, but significantly higher than that in patients with low vision and a reference population. The SF-12 mental composite score in study patients was similar to those of all 3 comparison groups. CONCLUSIONS: Patients with bilateral severe AMD have vision-related QOL similar to that of patients with low vision but significantly worse than those of patients with AMD of varying severity and persons without eye disease. This inability to perform vision-related daily tasks is not related to general health problems.

Aged↗
PubMed2005

Vision loss in Australia.

OBJECTIVE: To assess the prevalence and causes of vision loss in Australia and to project these data into the future. DESIGN: Synthesis of data from two cross-sectional population-based cohort studies--the Melbourne Visual Impairment Project and the Blue Mountains Eye Study--and extrapolation to the entire Australian population. SETTING AND PARTICIPANTS: 8376 community and 533 nursing home residents recruited between 1992 and 1996 in urban and rural Victoria and New South Wales. MAIN OUTCOME MEASURES: Age-standardised prevalence of low vision (visual acuity < 6/12) and blindness (visual acuity < 6/60) (both measured in the best eye, with spectacles if usually worn for distance vision), and their causes for the Australian population for 2000 to 2024, projected from Australian Bureau of Statistics population data. RESULTS: In 2004, 480,300 Australians were estimated to have low vision, including 50,600 with blindness. The most common causes of low vision were undercorrected refractive error (62%), cataract (14%) and age-related macular degeneration (10%). The latter was responsible for almost half of all cases of blindness. The numbers of people with low vision and blindness are projected to almost double by 2024. CONCLUSIONS: Vision loss in Australia is a much bigger problem than is usually recognised; 76% of low vision is caused by uncorrected refractive error or cataract, both readily treatable. However, the prevention and treatment of macular degeneration poses a major challenge.

Adult↗
PubMed2004

Low contrast vision function predicts subsequent acuity loss in an aged population: the SKI study.

Can vision tests predict subsequent loss of acuity? The association between performance on several low contrast spatial vision measures, glare recovery, color discrimination, flicker sensitivity, stereopsis and ocular disease status at baseline and acuity loss 4.4 years later was examined in a large aged random sample with good initial acuity. In univariate analyses, several vision measures, retinal disease status and age were each significant predictors of subsequent acuity loss. In a multiple regression analysis, only low contrast spatial vision was a significant predictor, but the other vision measures, retinal disease status and age were not. For each doubling of low contrast spatial vision threshold at baseline, individuals were more than two times as likely to suffer subsequent significant visual acuity loss. Tests of low contrast spatial vision are strong predictors of significant subsequent visual acuity loss. These findings have implications for clinical trials, clinical management, and acceptance of these measures into clinical practice.

Aged↗
PubMed2004

Reliability and validity of the Melbourne Edge Test and High/Low Contrast Visual Acuity chart.

PURPOSE: The purposes of the study were to investigate the test-retest reliability and the validity of new versions of the Melbourne Edge Test (MET) and the High/Low Contrast Visual Acuity (H/LCVA) chart and to investigate the agreement between the original and new versions. METHODS: The MET original photographic version, MET new light box version, H/LCVA Chart original photographic version, H/LCVA Chart new printed version, and the Pelli-Robson chart were administered twice to one eye of 22 subjects with low vision and 20 soft contact lenses wearers. RESULTS: For the low vision group, the test-retest 95% limits of agreement were +/- 5.2 dB for the MET new light box version and +/- 0.39 logarithm of the minimum angle of resolution (logMAR) for the LCVA component of the H/LCVA new printed version. For the soft contact lens group, the test-retest 95% limits of agreement were +/- 2.1 dB for the MET new light box version and +/- 0.26 logMAR for the LCVA component of the H/LCVA new printed version. Moderate to high correlations were obtained between contrast sensitivity tests, thus providing evidence of validity. Scores obtained for the new test versions were significantly higher than the original versions (p < 0.01). CONCLUSIONS: Of all the tests administered, the MET original photographic version and the Pelli-Robson Chart had the highest test-retest reliability for the low vision group. For the soft contact lens group, the H/LCVA original version (low contrast letters, 18% Weber) and the Pelli-Robson Chart had the highest reliability.

Adolescent↗
PubMed1998

The psychosocial impact of macular degeneration.

BACKGROUND: Age-related macular degeneration (AMD), the leading cause of irreversible blindness and low vision among the elderly, has not been well studied with regard to its impact on daily life. This study was designed to demonstrate the impact of AMD on quality of life, emotional distress, and functional level. PARTICIPANTS: The study sample consisted of 86 elderly adults (average age, 79 years) with AMD who were legally blind in at least 1 eye. Participants completed a battery of measures that included the Quality of Well-being Scale, the Instrumental Activities of Daily Living index, self-rated general health status, and the Profile of Mood States. RESULTS: Persons with AMD experienced significant reductions in key aspects of daily life. Their ratings for quality of life (average Quality of Well-being Scale score=0.581) and emotional distress (average Profile of Mood States total score=65.36) were significantly worse than those for similarly aged community adults and were comparable with those reported by people with chronic illnesses (eg, arthritis, chronic obstructive pulmonary disease, acquired immunodeficiency syndrome, and bone marrow transplants). Patients with AMD were also more likely than a national sample of elderly individuals to need help with daily activities. Visual acuity was related to ability to carry out daily activities (Instrumental Activities of Daily Living, r=0.28, P=.008). Quality of life ratings were significantly related to the ability to carry out daily activities (r=-0.38, P=.001), self-rated general health status (r=-0.21, P=.05), and emotional distress (Profile of Mood States total score, r=-0.25, P=.02). Individuals with a shorter period of perceived vision loss were more likely to report high levels of emotional distress (r=-0.24, P=.03) than those with a longer period of perceived vision loss. Further, those who were blind in 1 eye were even more significantly distressed than those who were blind in both eyes. CONCLUSIONS: Elderly persons with AMD causing legal blindness in 1 or both eyes have significant emotional distress and profoundly reduced quality of life and need help with key daily activities.

Activities of Daily Living↗
PubMed2006

A multicenter, retrospective pilot study of resource use and costs associated with severity of disease in glaucoma.

OBJECTIVE: To examine resource consumption and the direct costs of treating glaucoma at different disease severity levels. DESIGN: Observational, retrospective cohort study based on medical record review. PARTICIPANTS: One hundred fifty-one records of patients with primary open-angle or normal-tension glaucoma, glaucoma suspect, or ocular hypertension (age > or =18 years) were randomly selected from 12 sites in the United States and stratified according to severity based on International Classification of Diseases, Ninth Revision, Clinical Modification codes. Patients had to have been followed up for a minimum of 5 years. Patients with concomitant ocular disease likely to affect glaucoma treatment-related resource consumption were excluded. METHODS: Glaucoma severity was assessed and assigned using a 6-stage glaucoma staging system, modified from the Bascom Palmer (Hodapp-Anderson-Parrish) system. Clinical and resource use data were collected from the medical record review. Resource consumption for low-vision care and vision rehabilitation was estimated for patients with end-stage disease based on specialist surveys. For each stage of disease, publicly available economic data were then applied to assign resource valuation and estimate patient-level direct costs from the payer perspective. MAIN OUTCOME MEASURES: Average annual resource use and estimated total annual direct cost of treatment were calculated at the patient level and stratified by stage of disease. Direct costs by specific resource types, including ophthalmology visits, glaucoma surgeries, medications, visual field examinations, and other glaucoma services, were also assessed. RESULTS: Direct ophthalmology-related resource use, including ophthalmology visits, glaucoma surgeries, and medication use, increased as disease severity worsened. Average direct cost of treatment ranged from $623 per patient per year for glaucoma suspects or patients with early-stage disease to $2511 per patient per year for patients with end-stage disease. Medication costs composed the largest proportion of total direct cost for all stages of disease (range, 24%-61%). CONCLUSIONS: The study results suggest that resource use and direct cost of glaucoma management increase with worsening disease severity. Based on these findings, a glaucoma treatment that delays the progression of disease could have the potential to significantly reduce the health economic burden of this chronic disease over many years.

Adult↗
PubMed1988

Visual rehabilitation of patients with advanced stages of glaucoma, optic atrophy, myopia or retinitis pigmentosa.

Ninety-six patients with advanced stages of glaucoma, optic atrophy, myopia or retinitis pigmentosa (RP) who could not manage with ordinary spectacles or simple magnifying aids were taken care of at the Low Vision Clinic for rehabilitation and followed for an average of 3.6 years (the glaucoma group) up to an average of 6.0 years (the optic atrophy group). They were given high power optical aids and subjected to educational training in the proper use of these aids for best utilization of residual vision. Many of them (for optic atrophy as high a percentage as 40.7) were taught to use extra macular retina by means of eccentric viewing technique. The mean age of the oldest group, the glaucoma patients, was 69.3 years. The three other groups were about 20 to 25 years younger, on an average. (Another 35 patients were seen for the first series of visits but could not be followed up, the main reasons being death (13 patients) and moving out of the area (9 patients). The mean power of the aids (mainly telescopes) used for distance vision was 2.1 x (RP)-5.3 x (optic atrophy). Increased near addition and hyperocular lenses were the main aids for reading and near vision, the mean power being 17.0 dioptres (glaucoma)-23.5 dioptres (RP)(4.3 x -5.9 x). Aids were also provided for intermediate distance and for "spot use". The mean number of series of visits was 3.1 (myopia)-3.5 (glaucoma) and the average number of 1 h training sessions 2.2 (glaucoma)-2.5 (optic atrophy, RP) per series of visits. With aids and educational training, the mean visual acuity improved on the first series of visits from 0.31 to 0.60 for the glaucoma group, from 0.19 to 0.70 for the optic atrophy group, from 0.12 to 0.68 for the myopes and from 0.35 to 0.52 for the RP group. After the last series of visits acuity was still as good as 0.51, 0.61, 0.73 and 0.45, respectively. The number of individuals able to read newspaper text increased from 16.1% to 100.0% for the glaucoma patients, from 14.8% to 100.0% for the optic atrophy patients, from 75.0% to 100.0% for the myopes, and from 50.0% to 95.5% for the RP patients. The results show clearly that the methods used for rehabilitation of patients with glaucoma, optic atrophy, myopia or RP through optical aids and sessions of educational training are very successful, with substantial improvement of life quality.

Adolescent↗
PubMed1995

A computer and video display based system for training eccentric viewing in macular degeneration with an absolute central scotoma.

A new approach designed to establish the most suitable area for eccentric viewing and to teach and train patients with severe age-related macular degeneration (AMD) to use the eccentric viewing technique is described. Using a computer and video display based system, as well as software written specifically for this purpose, we investigated and trained ten consecutive patients with AMD. The patients were 80.1 + or - 5.6 years old, on average. All of them had an absolute central scotoma. Mean visual acuity was 0.035 + or - 0.016. After 30 min of testing, instruction and reading on the screen, followed by 2.6 + or - 0.69 one-hour training sessions, on average, with the low vision therapist, reading newspaper and book texts with the aid of hyperoculars or aplanatic systems and a very short reading distance, the patients achieved a reading speed of 58.9 + or - 19.7 words/min, significantly (p<0.001) higher than the initial speed when reading on the screen, 11.5 + or - 4.5 words/min.

Aged↗
PubMed2005

The relationship between word length and threshold character size in patients with central scotoma and eccentric fixation.

BACKGROUND: Understanding limitations on text reading with eccentric fixation is of major concern in low vision research. Our objective was to determine, in patients with a central scotoma, whether threshold character size is similar for different word lengths and paragraphed texts. METHODS: In 19 patients, we retrospectively analyzed the relationship between minimum readable character size for isolated words and text. Isolated letters, two, five, and ten-letter words and a paragraphed text were presented randomly through a scanning laser ophthalmoscope in eight different character sizes. RESULTS: Threshold character size varied according to the text stimulus (p<0.05). Threshold character sizes for single letters and two-letter words were matched (p>0.99), as were those for five-letter words, ten-letter words, and paragraphed text (p>0.99). Threshold character size for single letters and two-letter words was significantly lower than that measured with other text stimuli. DISCUSSION: Reading performance is influenced by a variety of factors such as crowding, contextual effects, visual span, degree of oculomotor adaptation needed, and frequency of a defined word. Globally, when reading with a central scotoma, it appears that within word characteristics have more impact than inter-word parameters on threshold character size.

Adult↗
PubMed2006

Nonmedical economic consequences attributable to visual impairment: a nation-wide approach in France.

The nonmedical costs of visual impairment are crucial when allocating resources for prevention or treatment programs. Were analyzed the data from two representative nationwide French surveys aimed at documenting impairments that included 14,603 subjects living in institutions and 16,945 in the community. Three groups were identified: blind (light perception), low vision (loss of shape perception, LV), and controls. Item consumption was standardized on confounding factors using logistic regression. Costs attributable to visual impairment were estimated from control subjects. National nonmedical costs due to visual impairment were euro 9,806 million, arising mostly from LV (euro 8,735 million). The annual average cost/subject was euro 7,242 for LV and euro 15,679 for blindness. Loss of family income was euro 4,552 million, the burden on the caregiver euro 2,525 million, paid assistance euro 2,025 million, social allowances euro 0,942 million, and unmet needs euro 5,553 million. Resource allocation strategies aimed at controlling visual impairment should cover all relevant economic dimensions, including nonmedical items.

Activities of Daily Living↗
PubMed2005

Generic and customized digital image enhancement filters for the visually impaired.

This study compares the effectiveness of various image enhancement filters for improving the perceived visibility of coloured digital natural images for people with visual impairment. Generic filters were compared with Peli's adaptive enhancement and adaptive thresholding and custom-devised filters based on each subject's contrast sensitivity loss. Subjects with low vision made within filter rankings followed by between filter ratings. In general, subjects preferred filters with lower gains. Unsharp masking resulted in a significant increase in perceived visibility for some image types (p < or = 0.05) while Peli's adaptive enhancement, edge enhancement and histogram equalization resulted in borderline improvements. Adaptive thresholding and the custom devised filter did not result in overall improvements in perceived visibility.

Adult↗
PubMed2003

The visually impaired child.

This article discusses the causes of childhood blindness and how the primary care provider may begin the appropriate steps toward diagnosing and managing the visually impaired child. Community resources (see Box 3) and low-vision programs in schools should be used so that parents do not need to reinvent strategies to raise a blind child. Worldwide, childhood blindness, which places is a tremendous burden on families and communities of the third world, is mostly preventable with improved hygiene, diet, and immunization.

Blindness↗
PubMed2002

Mr. Chips 2002: new insights from an ideal-observer model of reading.

The integration of visual, lexical, and oculomotor information is a critical part of reading. Mr. Chips is an ideal-observer model that combines these sources of information optimally to read simple texts in the minimum number of saccades. This model provides a computational framework for interpreting human reading saccades in both normal and low vision. The purpose of this paper is to report performance of the model for conditions emulating reading with normal vision--a visual span of nine characters, multiplicative saccade noise with a standard deviation of 30%, and texts based on three full-length children's books. Comparison of fixation locations by humans and Mr. Chips revealed: (1) that both exhibit very similar word-skipping behavior; (2) both show initial fixations near the center of words, but with a systematic difference suggestive of an asymmetry in the human visual span; and (3) differences in the pattern of refixations within words that may uncover non-optimal lexical inference by human readers. A human context effect--30% difference in mean saccade size between continuous text and random sequences of words--was very similar to the 25% effect for the model associated with a corresponding difference in the predictability of text words. Overall, our findings show that many of the complicated aspects of human reading saccades can be explained concisely by early information-processing constraints.

Computer Simulation↗
PubMed2001

Prevalence and causes of visual impairment according to World Health Organization and United States criteria in an aged, urban Scandinavian population: the Copenhagen City Eye Study.

PURPOSE: To evaluate the prevalence and causes of visual impairment in an epidemiologic study of aged, urban individuals in Denmark. DESIGN: Cross-sectional study. PARTICIPANTS: The study population consisted of 1000 randomly selected residents aged 60 to 80 years in Copenhagen, Denmark. Of 976 eligible persons, 946 (96.9%) could be examined. Information about best-corrected visual acuity (VA) was obtained from 944 cooperative persons (96.7%). METHODS: Data from the Copenhagen City Eye Study were used to assess the cause-specific prevalence of visual impairment as defined by the World Health Organization (WHO) (VA worse than 20/60-20/400 in the better eye) and the criteria used most commonly in the United States (VA worse than 20/40 but better than 20/200 in the better eye). Eligible subjects underwent an extensive ophthalmologic examination at The National University Hospital of Denmark. MAIN OUTCOME MEASURES: Best-corrected VA and primary causes of visual impairment. RESULTS: The prevalence of low vision according to the WHO definition ranged from 2.6% in subjects aged 70 to 74 years to 4.8% in subjects 75 to 80 years of age, with an age-adjusted relative prevalence of 1.58%. Using the U.S. definition, the overall age-adjusted prevalence of visual impairment was 2.9%. The causes of visual impairment according to the WHO criteria were age-related macular degeneration (AMD) (44.4%), cataract (33.3%), glaucoma in combination with cataract (11.1%), myopic macular degeneration (5.6%), and diabetic retinopathy (5.6%). However, according to the U.S. criteria, cataract was the most frequent primary cause (50.0%) and AMD was the second most frequent primary cause (34.4%) of visual impairment. Furthermore, using the U.S. criteria diabetic retinopathy was revealed as equally important as AMD and cataract as a cause of visual impairment among persons aged 65 to 69 years (33.3%). CONCLUSIONS: Increasing age was an independent predictor of visual impairment. Cataract and AMD were the leading causes. Adequate implementation of surgery to treat cataract could reduce visual impairment by 33.3% according to the WHO criteria and by 50% according to the U.S. criteria.

Age Distribution↗
PubMed1988

Teaching ophthalmology residents about rehabilitation.

Ophthalmology is a medical specialty which deals with large numbers of patients who have irreversible impairments. A survey of all ophthalmology residency programs in the United States found that most programs require that residents receive training in low vision aids and devices, but they do not require training in seven other topics concerning the rehabilitation of visually impaired and blind patients. Those programs that do offer training in rehabilitation rely heavily on clinical training. Since practicing ophthalmologists themselves have an incomplete knowledge of the rehabilitation system, it is unlikely that the clinical model will provide residents with sufficient information about rehabilitation. Ophthalmologists need formal training about the rehabilitation process in order to ensure that their patients receive adequate referrals.

Blindness↗
PubMed1992

Visual rehabilitation. The challenge, responsibility, and reward.

BACKGROUND: A multispecialty ophthalmology clinic created a not-for-profit foundation to establish a center for visual rehabilitation. METHODS: The Center's objective of equipping and enabling visually impaired people to lead more productive, independent, and satisfying lives by improving their remaining functional sight is performed through a four-phase program comprised of an intake interview, low vision examination, rehabilitation training, and counseling. RESULTS: Since its inception in 1986, the Center has cared for 947 females and 511 males. Although the majority of the patients examined are 61 to 90 years of age, all age groups have received care, including 41 patients younger than 10 years of age and 42 patients 91 years of age or older. CONCLUSION: The role of the ophthalmologist in the visual rehabilitation process is pivotal. The author acknowledges that most practices are unable to develop such a center. A number of suggestions are made, however, that may enable many practices to participate in the rehabilitation of their patients.

Adolescent↗
PubMed2000

Development of a shorter version of the geriatric depression scale for visually impaired older patients.

OBJECTIVE: To validate a shorter version of the Geriatric Depression Scale (GDS) for older, visually impaired patients. PARTICIPANTS: Subjects were 70 visually impaired adults over age 65 who were presenting for services at a low vision clinic. METHOD: Subjects were interviewed by a geriatric nurse practitioner. A structured clinical interview was used to ascertain major depression, and the 15-item GDS was used to assess depressive symptoms. A multiple logistic regression was performed in which the dependent variable was clinical diagnosis of major depression and the independent variables were the 15 GDS items. Four items were significant, and were used to form the GDS-Abbreviated (GDS-A) scale. Sensitivity and specificity analyses were performed on various combinations of these four items to generate an effective cutoff score. RESULTS: Endorsing any two or more of the following four items--a) dissatisfied with life, (b) feeling helpless, (c) reporting problems with memory, and (d) lost activities and interests-yielded the best results with a sensitivity of .71 and a specificity of .88. This GDS-A cutoff score better differentiates depressed from nondepressed individuals than the cutoff score of 5 that is recommended for the GDS-15. CONCLUSION: The GDS-A's short format and strong discriminating ability make it an effective, convenient tool for screening visually impaired, older patients for depression.

Aged↗
PubMed2001

[Illumination conditions of visually impaired people under private domestic circumstances - clinical study on 91 patients].

BACKGROUND: The illuminance and quality of illumination are important factors for visually impaired people to improve contrast sensitivity and reduce glare sensitivity at domestic reading places. The ability of visually impaired people to read can often be improved by simple strategies. At the onset of multiple ophthalmic diseases an optimum of lighting is often the tool of choice to restore reading capability. PATIENTS AND METHODS: 91 visually impaired people were included in this study. 76 were equipped with optical reading tools and 15 used a television reading aid. The illumination conditions of reading places were investigated. This included measurements of illuminance and information about the light source and localization, direction of light and modelling. The understanding of the importance of optimal illumination was judged by a graded scale from 1 - 5. RESULTS: Twenty-two of the 76 visually impaired people equipped with optimal reading tools were using an extra reading place. All others used livingroom or kitchen tables as their preferred reading place. 10 % of the reading places had a illuminance of above 5000 lx, whereas 63 % had less than 500 lx. Incandescent lamps dominated as artificial light sources. In 60 % of all reading places ceiling light sources were predominant. Only 40 % of the patients used an additional reading place illumination. For television reading aids the ceiling light caused a decrease of contrast sensitivity in 1 % - 7 %. If questioned, 90 % of the patients were highly sensitive to problems of good illumination of their reading places. This is, as our study revealed, in contrast to the conditions under which most of the visually impaired people read. CONCLUSIONS: Domestic reading places revealed considerable deficits concerning the illumination. Most visually impaired people do not realize this problem. Ophthalmologists, opticians, low-vision-, orientation- and mobility-trainers are recommended for rehabilitation.

Aged↗