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At least 73 records · Page 4Linked to original sources
PubMed2004

Vision impairment and combined vision and hearing impairment predict cognitive and functional decline in older women.

OBJECTIVES: To determine the association between vision and hearing impairment and subsequent cognitive and functional decline in community-residing older women. DESIGN: Prospective cohort study. SETTING: Four metropolitan areas of the United States. PARTICIPANTS: A total of 6,112 women aged 69 and older participating in the Study of Osteoporotic Fractures (SOF) between 1992 and 1994. MEASUREMENTS: Five thousand three hundred forty-five participants had hearing measured, 1,668 had visual acuity measured, and 1,636 had both measured. Visual impairment was defined as corrected vision worse than 20/40. Hearing impairment was defined as the inability to hear a tone of 40 dB or greater at 2,000 hertz. Participants completed the modified Mini-Mental State Examination and/or a functional status assessment at baseline and follow-up. Cognitive and functional decline were defined as the amount of decline from baseline to follow-up that exceeded the observed average change in scores by at least 1 standard deviation. RESULTS: About one-sixth (15.7%) of the sample had cognitive decline; 10.1% had functional decline. In multivariate models adjusted for sociodemographic characteristics and chronic conditions, vision impairment at baseline was associated with cognitive (odds ratio (OR)=1.78, 95% confidence interval (CI)=1.21-2.61) and functional (OR=1.79, 95% CI=1.15-2.79) decline. Hearing impairment was not associated with cognitive or functional decline. Combined impairment was associated with the greatest odds for cognitive (OR=2.19, 95% CI=1.26-3.81) and functional (OR=1.87, 95% CI=1.01-3.47) decline. CONCLUSION: Sensory impairment is associated with cognitive and functional decline in older women. Studies are needed to determine whether treatment of vision and hearing impairment can decrease the risk for cognitive and functional decline.

Activities of Daily Living↗
PubMed2006

Use of an augmented-vision device for visual search by patients with tunnel vision.

PURPOSE: To study the effect of an augmented-vision device that superimposes minified contour images over natural vision on visual search performance of patients with tunnel vision. METHODS: Twelve subjects with tunnel vision searched for targets presented outside their visual fields (VFs) on a blank background under three cue conditions (with contour cues provided by the device, with auditory cues, and without cues). Three subjects (VF, 8 degrees -11 degrees wide) carried out the search over a 90 degrees x 74 degrees area, and nine subjects (VF, 7 degrees -16 degrees wide) carried out the search over a 66 degrees x 52 degrees area. Eye and head movements were recorded for performance analyses that included directness of search path, search time, and gaze speed. RESULTS: Directness of the search path was greatly and significantly improved when the contour or auditory cues were provided in the larger and the smaller area searches. When using the device, a significant reduction in search time (28% approximately 74%) was demonstrated by all three subjects in the larger area search and by subjects with VFs wider than 10 degrees in the smaller area search (average, 22%). Directness and gaze speed accounted for 90% of the variability of search time. CONCLUSIONS: Although performance improvement with the device for the larger search area was obvious, whether it was helpful for the smaller search area depended on VF and gaze speed. Because improvement in directness was demonstrated, increased gaze speed, which could result from further training and adaptation to the device, might enable patients with small VFs to benefit from the device for visual search tasks.

Eye Movements↗
PubMedDate not supplied

The Vision First Check Program in British Columbia: a preschool vision screening program for children age two and age three.

The Vision First Check Program was developed in consultation with ophthalmology and optometry representatives on the provincial Vision Advisory Committee and piloted by participating optometrists in four communities in BC between January and June 1998. This preschool vision screening program provides for one vision screening for children aged two and three at no cost to the family or the Medical Services Plan of BC. The screening is by optometrists, the marketing of the program is coordinated through public health, and the data collection is coordinated through the Medical Services Plan as a no-fee item.

British Columbia↗
PubMed2001

Restoration of vision IV: role of compensatory soma swelling of surviving retinal ganglion cells in recovery of vision after optic nerve crush.

PURPOSE: Diffuse axonal injury following partial optic nerve crush (ONC) leads to severe visual deficits from which rats can partially recover within 2-3 weeks. To evaluate tbc role of surviving retinal ganglion cells (RGCS) in recovery, we have observed their morphology repeatedly in vivo with ICON-microscopy and correlated cell size changes with recovery of vision which we observed in parallel in the same animals. METHODS: After rats had learned a visual contrast discrimination task using an automated, computer-based test, RGCs were labeled retrogradely with fluorescent beads. Animals then received either no lesion, a complete axotomy or bilateral mild, moderate or severe ONC. Before surgery and for 40 days post-operatively, ROC number and soma size was repeatedly quantified every five days with tbc in vivo confocal neuroimaging method (Sabel et al., Nature med. 3, 1997, p. 244). In parallel, visual function was quantified with the contrast-discrimination task. RESULTS: After ONC about 70 % of the ROCs died after having undergone a fast and massive soma swelling. The extent of cell death was independent of crush severity. RGCs surviving the injury did not change their body size over time in the severe group and these animals also did not recover their vision. In contrast, after a mild or moderate crush, about half of the surviving RGCs experienced a slow and moderate, "compensatory" cell soma swelling and the rats showed partial recovery of vision. Both the number of RGCs showing such compensatory soma swelling and the extent of the swelling correlated highly (r = 0.96) with recovery of contrast discrimination performance at post-operative days 23 and 38. CONCLUSIONS: Depending en the time course and extent, soma swelling after neurotrauma may be associated either with cell death or recovery of function. Because of the very high correlation between extent of recovery and amount of soma swelling, moderate soma swelling contributes in a prominent way to recovery of vision. We believe that these cells provide an important structural substrate for neuronal tissue repair and therefore term these cells "compensatory neurons".

Adaptation, Physiological↗
PubMed2002

[Functional improvement after vision rehabilitation in low monocular vision after myopic macular degeneration and retinal detachment].

PURPOSE: We present a case of a 62 year-old woman, with a single eye functional vision (VA of 0.16) who improved her vision after following a vision rehabilitation program, which included optical and non-optical devices for daily performance. CONCLUSIONS: A correct optometric evaluation and a training program are key factors to improve quality of life in low vision patients, whose ocular pathology allows no other treatment.

Female↗
PubMed1985

A practical guide for colour-vision examination: report of the Standardization Committee of the International Research Group on Colour-Vision Deficiencies.

There are different types and degrees of colour deficiency and some types of defect occur more frequently than others. Several different techniques are used for examining colour vision and many different tests are available commercially. Clinical tests have three aims: to screen for colour deficiency, to diagnose or classify the type of defect and to grade the severity of the defect. Individual tests do not fulfil all three aims and a test battery is recommended for any detailed colour-vision examination or for giving occupational advice. This paper provides information about congenital and acquired colour-vision defects and lists the principal colour-vision tests. Standardized test methods and viewing conditions are described. The efficiency of each test, for screening, diagnosis and grading is indicated and appropriate test batteries are recommended for different testing requirements.

Color Perception Tests↗
PubMed1986

Suggested vision standards for drivers in the United States with vision ranging from 20/175 (6/52) to 20/50 (6/15).

This article creates two categories for individuals with vision ranging from 20/175 (6/52) to 20/50 (6/15). Statistically, there are approximately 532,000 drivers with vision ranging from 20/175 (6/52) to 20/100 (6/30) and 56,000 drivers with vision ranging from 20/80 (6/24) to 20/50 (6/15). The author contends that the plan to test the vision of a number of drivers over the next four years will turn up a large number of failures. This will result in the loss of licenses and conceivably cause many people to lose their jobs. One way to avoid this is to issue limited licenses. It is important for the Department of Motor Vehicles to consider this step.

Automobile Driving↗
PubMed1995

A novel approach to providing educationally based low vision services and outreach clinical and vision support services to the visually impaired.

BACKGROUND: The Perkins Low Vision Service is affiliated with the New England Eye Institute, the primary teaching clinic of the New England College of Optometry. Low Vision Services for patients of all ages as well as vision services for the multi-impaired are provided on site at the Perkins School for the Blind in Watertown, Massachusetts. RESULTS: Evaluations are provided by the low vision team comprised of specialists with expertise in pediatric and rehabilitative optometry, special education, orientation and mobility training, rehabilitation teaching and the interns at the New England College of Optometry. The full scope of services offered as well as alternative modes of practice employed will be discussed.

Adolescent↗
PubMed2006

The association between vision quality of life and academics as measured by the College of Optometrists in Vision Development Quality of Life questionnaire.

BACKGROUND: Undetected visual problems are one of the causes of academic difficulties in the classroom. An easily administered screening device that identifies children who are likely to do poorly in school because of vision problems would be a valuable tool. The screening should be able to be performed by a classroom teacher or aide. The objective of this study was to determine if there was an association between vision-related quality-of-life factors (19-item College of Optometrists in Vision Development Quality of Life [COVD-QOL] questionnaire checklist) and academic performance. A secondary objective was to determine whether student and parent responses to the questionnaire would be similar. METHODS: Ninety-one parents or guardians and their children, attending the third, fifth, and seventh grades in a public school participated in this study. Both the parent or guardian and student independently completed the checklist. The scores of both groups were compared with the Stanford IX test scores for total reading, total math, total spelling, and total battery scores of the Stanford IX. The parent or guardian and student scores were compared to evaluate the agreement (intergroup reliability). RESULTS: Parent or guardian and student checklist scores were compared. The Wilcoxon Signed Rank test showed that the mean scores for the parent or guardian were significantly lower than for third grade students and also for the total sample. Visual symptoms were found to be inversely correlated to academic performance; the lower the academic score, the more symptoms were reported. Symptoms reported by third grade students and their parents tended to be more highly correlated with academic scores. In general, symptoms reported by the parent were more highly correlated with academic score than the symptoms reported by the student. CONCLUSION: The COVD-QOL questionnaire is a cost-effective, quick, and easy tool that may be used in school screening to identify possible visual symptoms that are correlated to academic performance.

Child↗
PubMed2003

Assessment of colour vision as a screening test for sight threatening diabetic retinopathy before loss of vision.

AIM: To assess the effects of sight threatening diabetic retinopathy (STDR) on colour vision and to evaluate automated tritan contrast threshold (TCT) testing for STDR screening before significant visual loss. METHOD: Patients were recruited from a hospital based photographic screening clinic. All subjects underwent best corrected Snellen visual acuity (BCVA) and those with 20/30 vision or worse were excluded. Automated TCT was performed with a computer controlled, cathode ray tube based technique. The system produced a series of sinusoidal, standardised equiluminant chromatic gratings along a tritan confusion axis. Grading of diabetic retinopathy was made by one of the team of experienced ophthalmic registrars (SpR) using slit lamp biomicroscopy and a 78D lens; HbA(1c) and urine albumin were also tested. RESULTS: Patients with STDR had significantly worse TCT despite normal BCVA (p<0.0001). TCT yielded a sensitivity of 100% for detecting diabetic maculopathy and 94% for STDR with a specificity of 95%. Logistic regression analyses showed that TCT (p<0.001) and HbA(1c) (p<0.05) correlated significantly with the presence of STDR but duration of diabetes, urine albumin counts, and BCVA failed to show any significant correlation. No associations between TCT and duration of disease, TCT and HbA(1c), and TCT and urine albumin counts were found. CONCLUSION: Tritan colour vision deficiency was observed in patients with STDR despite their normal BCVA. These results indicate that automated TCT assessment is an effective and clinically viable technique for detecting STDR, particularly diabetic maculopathy, before visual loss.

Adolescent↗
PubMed1996

Leadership and vision in the NHS: how do we create the "vision thing"?

The development of NHS trusts has been a major part of the NHS reforms in the United Kingdom. The creation of trust boards has coincided with significant pressures from the combined forces for change and consolidation within publicly financed health care in the UK. The development of a long term strategic vision for trusts to ensure long-term survival is imperative. Considers evidence from international researchers and translates this into the context of NHS trusts. Discusses how they define and identify vision and ensure that vision building can be communicated and understood by key stakeholders within and outside the organization. Offers several practical suggestions on how their vision can be monitored and evaluated within the organization.

Evaluation Studies as Topic↗
PubMed2004

Effect of polymorphic colour vision for fruit detection in the spider monkey Ateles geoffroyi, and its implications for the maintenance of polymorphic colour vision in platyrrhine monkeys.

Most platyrrhine monkeys have an X-linked tri-allelic polymorphism for medium and long wavelength (M/L) sensitive cone photopigments. These pigments' sensitivity maxima (lambdamax) range from 535 to 562 nm. All animals also have an autosomally coded short-wavelength-sensitive (S) cone pigment. In populations with three M/L alleles there are six different colour vision phenotypes. Heterozygous females have trichromatic colour vision, while males and homozygous females are dichromats. The selective basis for this polymorphism is not understood, but is probably affected by the costs and benefits of trichromatic compared to dichromatic colour vision. For example, it has been suggested that trichromats are better equipped than dichromats to detect fruit against a leaf background. To investigate this possibility, we modeled fruit detection by various colour vision phenotypes present in the frugivorous spider monkey, Ateles geoffroyi. Our study population is thought to have three M/L alleles with cone pigment lambdamax values close to 535, 550 and 562 nm. The model predicted that all trichromat phenotypes had an advantage over dichromats, and the 535/562 nm phenotype was best; however, the model predicted that dichromats could detect all of the fruit species consumed by spider monkeys. We conclude that the heterozygote advantage experienced by females may be the most plausible explanation for the maintenance of this polymorphism in A. geoffroyi. Nevertheless, more studies need to evaluate social foraging behaviour and the performance of different phenotypes of other New World monkeys to determine if this is a global explanation for this phenomena or more specific to A. geofforyi.

Alleles↗
PubMed1986

Evaluation of colour vision, mesopic vision, visual evoked potentials and lightness discrimination in adult amblyopes.

This is a study conducted on thirty adult strabismic and anisometropic amblyopes using colour vision tests, the lightness discrimination test, mesopic vision and visual evoked responses, in order to determine the probable site of the amblyopic defect. The results showed that, in its progressed stages, amblyopia is associated with eccentric fixation, abnormal hue discrimination, disturbed lightness discrimination and mesopic vision, and attenuation of the amplitude of the pattern visual evoked response. It is suggested that these abnormalities result from a defect involving the extrastriate higher visual association areas 18 & 19 of Brodmann.

Adult↗
PubMed2005

Preschool vision screening tests administered by nurse screeners compared with lay screeners in the vision in preschoolers study.

PURPOSE: To compare the performance of nurse screeners with that of lay screeners in administering preschool vision screening tests. METHODS: Trained nurse and lay screeners administered the Retinomax Autorefractor (Right Manufacturing, Virginia Beach, VA), SureSight Vision Screener (Welch Allyn, Inc., Skaneateles Falls, NY), crowded Linear Lea Symbols visual acuity (VA) test at 10 ft (Precision Vision, Inc., La Salle, IL), and Stereo Smile II test (Stereo Optical, Inc., Chicago, IL) to 3- to 5-year-old Head Start participants. Lay screeners also administered a crowded Single Lea Symbols VA test at 5 ft (Good-Lite, Inc.). Screening results were compared with the classification of the children according to the presence of one or more of four conditions (amblyopia, strabismus, significant refractive error, and unexplained reduced VA) based on the results of a gold standard eye examination by study-certified optometrists and ophthalmologists. The primary outcome measure was sensitivity for detecting children with one or more targeted conditions at 0.90 specificity. RESULTS: Nurse screeners achieved slightly higher sensitivities with the Retinomax, SureSight, and Stereo Smile II tests than did lay screeners; however, most differences were small and not statistically significant. Nurse screeners achieved significantly higher sensitivity with the Linear Lea Symbols VA test than did lay screeners. Lay screeners achieved strikingly higher sensitivity with the Single Lea Symbols VA test than did nurse or lay screeners using the Linear Lea Symbols VA test. Combining the Stereo Smile II test with each of the other tests did not result in improved sensitivities for detecting one or more targeted conditions. CONCLUSIONS: Nurse and lay screeners can achieve similar sensitivity, when specificity is set at 0.90, for detecting preschool children in need of a comprehensive eye examination.

Allied Health Personnel↗
PubMed1994

Assessment of functional vision performance: a new test for low vision patients.

Measures of functional vision are needed to assess elderly low vision patients, their success in using devices, and their ability to manage outside the treatment setting. A new test devised to measure functional ability through the performance of everyday tasks was administered to 94 patients who had acuities of 20/100 or worse in their better eye. Consisting of three versions and four subtests: spot reading, short-term text reading, identifying paper currency and clock reading, the test used standardized items and was timed. In a multiple regression model predicting test performance higher scores were associated with better near acuity (P = .002), higher education (P = .022) and higher levels of self-reported visual skills (P = .072). These predictors plus distance acuity, age and sex only accounted for 35 percent of the variance in test scores. Repeated administration of the test to a different group of 21 patients showed the test to be reliable (intraclass correlation = .85, P < .01) and to have no practice or version effects or differences between raters. This new test may be useful for natural history studies and clinical trials involving low vision patients but further evaluation of its sensitivity to change over time is required.

Adolescent↗
PubMed2005

Mechanisms selectively engaged in rivalry: normal vision habituates, rivalrous vision primes.

When rivalrous stimuli are presented intermittently, perception stabilises. This indicates the operation of perceptual memory across interruptions in stimulation. Here we show that a percept under non-rivalrous and rivalrous conditions has qualitatively different effects on subsequent rivalrous vision. When an image is perceived under rivalrous viewing, that image is more likely to be perceived in later rivalrous viewing: an effect of stabilisation or priming. When the same image is perceived under non-rivalrous viewing conditions, it is less likely to be perceived again during subsequent rivalrous viewing: an effect of adaptation or habituation. When these stimuli possess different attributes to those in subsequent vision their effect declines. This suggests that visual rivalry might recruit mechanisms that are not engaged in 'normal' non-rivalrous vision but perhaps dedicated to the resolution of competing sensory information.

Awareness↗
PubMed2004

Visual search and the conspicuity of coloured targets for colour vision normal and colour vision deficient observers.

BACKGROUND: Colour is known to facilitate visual search although its role as a determinant of target conspicuity is not so clear. People with abnormal colour vision have problems recognising and differentiating colours but the extent to which they may be at a disadvantage in visual search when redundant colour is a target attribute has not been investigated previously. METHOD: Six colour normal and 29 colour deficient subjects (7 P, 6 D, 7 PA, 9 DA) were instructed to find a diamond-shaped target embedded in a background of 138 differently shaped distracters and to report its position as quickly as possible. The target was redundantly colour-coded red, yellow, green, blue or white and the distracters had the same colours in various combinations. The target was uniquely colour-coded in some presentations, partially redundant in others and in some presentations the target and distracters had the same colour. In experiment 1 the displays were presented for 20 seconds and search time was measured; in experiment 2 the exposure time was 500 ms and the proportion of targets located correctly was taken as a measure of the target's conspicuity. RESULTS: Unique colour coding reduced search times significantly and greatly enhanced conspicuity but had no benefit when some distracters had the same colour as the target. Observers with colour vision deficiency had longer search times and the coloured targets were less conspicuous to them compared with colour normal observers. However, unique colour coding assisted their search, especially when the targets were red, blue or white. CONCLUSIONS: Observers with colour vision deficiency are less efficient than colour normal observers at visual search when the target is marked out by colour and coloured targets are less conspicuous for them.

Adult↗
PubMed2000

The activities of daily vision scale: a useful tool to assess fall risk in older adults with vision impairment.

OBJECTIVE: To evaluate the validity of the Activities of Daily Vision Scale (ADVS) as a tool to assess fall risk in older adults with vision impairment. DESIGN: Cross-sectional assessments of visual function and retrospective collection of fall data. SETTING: The outpatient medical clinics of an academic tertiary care community hospital. PARTICIPANTS: Randomly selected sample (n = 143) of older (> or = 65 years) patients seen at the outpatient medical clinics at Nassau County Medical Center in Long Island, New York. These patients had one or more of five ocular conditions: refractive errors (n = 90), cataracts (n = 77), glaucoma (n = 29), diabetic retinopathy (n = 19), and/or macular degeneration (n = 6). MEASUREMENTS: Visual function, assessed using the ADVS, demonstrated scores ranging from 0 (marked visual disability) to 100 (no visual difficulty). Fall history and the presence of eye disease were based on the self-recall of patients. Fall history was assessed retrospectively over a 1-year period from the time of the interview. RESULTS: Thirteen percent of the subjects reported having one or more falls during the 1-year period before the time of the interview. These subjects scored significantly lower on the ADVS compared with the scores of the group that did not report falls (74 +/- 22 vs 85 +/- 14, P < .01). Using a cutoff score of 90 points (10% loss of visual function on the ADVS), the ADVS had a 67% sensitivity in identifying those patients who had falls. Among the patients with glaucoma and those with diabetic retinopathy, the ADVS had a 100% sensitivity in identifying those patients who reported a history of falls. In patients with cataracts and refractive errors, the ADVS had a sensitivity of 82% and 64%, respectively, in identifying patients with a history of falls. The number of falls reported by the subjects showed no relationship with the ADVS scores. CONCLUSION: The results from this study suggest that the ADVS may prove to be a useful tool to assess fall risk in older adults with vision impairment, especially in those persons with glaucoma, diabetic retinopathy, and/or cataracts.

Accidental Falls↗