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At least 865 records · Page 48Linked to original sources
PubMed1999

The relationship of self-rated vision and hearing to functional status and well-being among seniors 70 years and older.

PURPOSE: To describe the relationship between self-reported visual and hearing impairment and an index of global functional status among seniors age 70 years or older. METHODS: A total of 7,320 United States community-dwelling persons aged 70 years or older participating in the 1993 Assets and Health Dynamics of the Oldest Old Survey (AHEAD) completed detailed questionnaires about their demographic, socioeconomic, and health status. Multivariate analyses of functional status (using a global index of functional status based on self-reported limitations in 11 activities) were conducted, controlling for demographic and socioeconomic status and common medical conditions, as well as independently for hearing and vision. RESULTS: Of the respondents, 27% rated their vision as fair or poor, whereas 25% rated their hearing as fair or poor. Controlling for demographic factors, socioeconomic status, medical conditions, and general health status, limitations in both vision and hearing correlated independently with worsened functional status. Controlling for income, wealth, and education did not greatly reduce the strength of the association between visual and hearing impairment and function. CONCLUSIONS: Visual and hearing impairment appear to have a significant relationship to overall functioning in the oldest old, regardless of income or wealth. By confirming these findings across income and household wealth groups, adjusted for medical conditions and general health status, in a nationally representative population of Americans age 70 years or older, this study provides a powerful added impetus to efforts for improving vision and hearing for all other Americans, including the oldest old.

Aged↗
PubMedDate not supplied

Lanthony 15-Hue Desaturated Test for screening of early color vision defects in uncomplicated juvenile diabetes.

PURPOSE: To identify the most appropriate test for screening of early color vision abnormalities in uncomplicated juvenile diabetes. METHODS: Enrolled in this study were 39 diabetic adolescents, characterized by optimal Early Treatment Diabetic Retinopathy Study criteria for visual acuity, transparent dioptric means and angiographically normal retinas. Color vision was examined with Standard Pseudoisochromatic Plates (Part 2, SPP2), Roth 28-Hue Test (R28), Farnsworth-Munsell 100-Hue Tests (FM100), and Lanthony 15-Hue Desaturated Test (L15). Color confusion score (CCS) and desaturation angle (DSAT) were measured on L15 only. Thirty-nine normal subjects served as a control group. Poor metabolic control was an exclusion criteria. RESULTS: CCS was significantly higher in the patients than in the controls (37.8 +/- 11.1 vs 0 +/- P < .001) and normal scores were found in only 4 diabetic patients. DSAT values were spread, not showing a well-defined axis of the defect. The results of FM100 were clinically reliable but affected by a longer execution time. R28 and SPP2 demonstrated a low sensitivity, as all patients scored normally with both tests. CONCLUSIONS: Impaired color vision is a common observation even in patients with uncomplicated juvenile diabetes. Our results indicate that L15 is the most suitable test for screening of early color vision abnormalities in these subjects.

Adolescent↗
PubMed2003

Risk factors for abnormal binocular vision after successful alignment of accommodative esotropia.

PURPOSE: The purpose of this study was to identify clinical factors associated with abnormal binocular vision outcomes among children with accommodative esotropia (ET) whose eyes were successfully realigned with spectacles only or with spectacles and surgery. METHODS: The participants were 69 children with accommodative ET who were followed up prospectively from the time of diagnosis. Clinical factors examined in this study included high accommodative convergence-to-accommodation (AC/A) relationship, high hyperopia, anisometropia, age of onset, and duration of eye misalignment. Binocular vision was assessed using measures of stereopsis, fusional vergence, sensory foveal fusion, and motion visual-evoked potential (mVEP). RESULTS: Children with a high AC/A relationship are 2.2 times more likely to have an absence of fusional vergence than are children with a normal AC/A relationship. Children having a duration of constant eye misalignment >/= 4 months before being successfully treated are 4.6 times more likely to have abnormal stereopsis, 33 times more likely to have no stereopsis, 37 times more likely to have an absence of fusional vergence, 31 times more likely to have an absence of sensory foveal fusion, and 17 times more likely to have an asymmetric mVEP response than children with a duration of constant ET diagnosed at 0 to 3 months. CONCLUSIONS: Following successful eye alignment, as many as 75% of patients with accommodative ET had anomalous binocular vision. A high AC/A relationship poses a significant risk for abnormal fusional vergence only. A constant eye misalignment lasting >/= 4 months poses a significant risk for anomalous binocular vision on all measures studied.

Accommodation, Ocular↗
PubMedDate not supplied

Computerized color-vision test based upon postreceptoral channel sensitivities.

An automated, computerized color-vision test was designed to diagnose congenital red-green color-vision defects. The observer viewed a yellow appearing CRT screen. The principle was to measure increment thresholds for three different chromaticities, the background yellow, a red, and a green chromaticity. Spatial and temporal parameters were chosen to favor parvocellular pathway mediation of thresholds. Thresholds for the three test stimuli were estimated by four-alternative forced-choice (4AFC), randomly interleaved staircases. Four 1.5-deg, 4.2 cd/m2 square pedestals were arranged as a 2 x 2 matrix around the center of the display with 15-minute separations. A trial incremented all four squares by 1.0 cd/m2 for 133 ms. One randomly chosen square included an extra increment of a test chromaticity. The observer identified the different appearing square using the cursor. Administration time was approximately 5 minutes. Normal trichromats showed clear Sloan notch as defined by log (deltaY/deltaR), whereas red-green color defectives generally showed little or no Sloan notch, indicating that their thresholds were mediated by their luminance system, not by the chromatic system. Data from 107 normal trichromats showed a mean Sloan notch of 0.654 (SD = 0.123). Among 16 color-vision defectives tested (2 protanopes, 1 protanomal, 6 deuteranopes, & 7 deuteranomals), the Sloan notch was between -0.062 and 0.353 for deutans and was < -0.10 for protans. A sufficient number of color-defective observers have not yet been tested to determine whether the test can reliably discriminate between protans and deutans. Nevertheless, the current data show that the test can work as a quick diagnostic procedure (functional trichromatism or dichromatism) of red-green color-vision defect.

Automation↗
PubMed1997

The validity of current clinical tests of contrast sensitivity and their ability to predict reading speed in low vision.

PURPOSE: Contrast sensitivity (CS) testing using chart tests of CS is becoming increasingly common in low vision assessment. Yet we know little about the validity of these charts, i.e. which region of the spatial frequency spectrum is being measured. In this study we aimed to determine the validity of currently available CS charts by comparison against oscilloscope-based CS. We also determined their relative ability to predict reading speed. METHODS: CS was measured with five commercially available charts and the contrast sensitivity function was determined with sinusoidal gratings presented on a Joyce screen using a two-alternative forced choice staircase technique in 36 observers with low vision and 3 with normal vision. Reading rate was also measured with the subject reading with his or her own optical low vision aid. RESULTS: The results show that the Pelli-Robson chart and the Cambridge gratings are good measures of medium to low spatial frequencies, as would be predicted from their design, while the Regan and UW charts correlated with medium to high frequencies. The Vistech chart was a good predictor of CS at each spatial frequency. CONCLUSIONS: The best chart test of CS depends on which region of the CS curve is of interest. All the charts were good predictors of reading rate.

Adult↗
PubMed2001

Age-related vision loss in the older adult: the role of the nurse practitioner in prevention and early detection.

Vision loss is a common problem in older adults and may result in functional impairment and accidental injury. The four most common causes of vision loss in this age group are age-related macular degeneration, cataracts, glaucoma, and diabetic retinopathy. The nurse practitioner has an important role in the prevention and early detection of these conditions. This article reviews scientific evidence on risk factors and preventative interventions for the causes of age-related vision loss. It also describes the important role of the nurse practitioner in assessment of eye health, so that conditions that may be damaging to vision may be detected early and monitored in the primary care setting.

Aged↗
PubMed1990

[Binocular vision after secondary lens implantation following vitreoretinal silicon oil surgery].

In 10 cases, aphakia after silicone oil surgery was corrected as follows: after completion of all retinal interventions, but not less than 3 months after silicone oil removal, an anterior chamber lens (Kelman Multiflex) was implanted. Binocular vision was interrupted for periods ranging from 4 months to 4.6 years (mean 2 years). Tests of the recovered binocular vision, on average 13 months after implantation of the lens, revealed simultaneous vision in 7 cases and exclusion in 2 (primary amblyopia; secondary divergent squint). Stereoscopic vision of 3800" was achieved in 4 cases, and of 200" in one. Four patients regained measurable fusion, between 6 and 29 diopters.

Adult↗
PubMed1998

Development of a questionnaire for measurement of vision-related quality of life.

PURPOSE: To define vision-related quality of life, to outline the development of a vision-specific quality of life instrument and to present the characteristics of a 10-item 'core' questionnaire. METHOD: A standard method included: 1. Generation of relevant issues by individual interviews with 38 visually impaired adults, consultation with 37 professionals and support workers and literature review. 2. Operationalisation, involving 58 ophthalmic patients. 3. Pre-testing, to maximise face validity and content validity, involving 184 individuals with a variety of different visual problems and social backgrounds. 4. Adoption of a modular approach to item selection. 5. Formal piloting in 92 individuals to establish reliability and construct validity. RESULTS: More than 232 items were tested of which 139 were considered suitable for a final question pool or 'parent' questionnaire (the VQOL). From this parent questionnaire individual items or groups of items can be selected. Ten broadly applicable items referring to physical, social and psychological issues were selected for the core questionnaire (the VCM1). The VCM1 has high reliability (alpha = 0.93) and validity. CONCLUSIONS: Any self-reported problem relating to vision may constitute a quality of life issue. A modular approach to item selection may provide the flexibility to investigate vision-related quality of life in a wide range of clinical settings, allowing detailed assessment of specific problems and also cross-study comparisons where appropriate.

Adult↗
PubMed2005

Vision and hearing impairment in aged care clients.

PURPOSE: To determine the frequency of sensory impairments among aged care clients. METHODS: We examined 188 persons aged 65-99 years being evaluated for aged care services at a geriatric assessment center, west of Sydney, Australia. Visual acuity was measured using a LogMAR chart. Visual impairment was defined in the better eye: mild < 20/40 to > or = 20/80, moderate < 20/80 to > or = 20/200, and severe < 20/200. Hearing function was assessed by portable pure-tone air-conduction audiometry. Hearing loss was defined using average hearing thresholds in the better ear: mild > 25 to < or = 40 decibels (dB), moderate > 40 to < or = 60dB, and severe > 60dB. RESULTS: Vision, hearing, or both were randomly tested in 96, 93, and 49 aged care clients, respectively. Vision impairment was found in 30.2% of clients. Distance vision could be improved with pinhole in 16.7% of 84 clients with presenting VA < 20/20. Moderate to severe hearing loss was present in 50.5%. Combined sensory impairment was detected in 22.5% of persons having both tests. The age-standardized proportions with vision impairment was 25.6%, higher than the rate (17.4%) found in the Blue Mountains Eye Study (BMES) community population, but lower than the 37.7% prevalence reported from the BMES nursing home sample. Hearing impairment was also more common in aged care clients (28.1% vs 17.5%). CONCLUSIONS: This study suggests a high prevalence of sensory impairment among older persons transitioning from independent community living to institutionalized care.

Aged↗
PubMed2003

Three-wall orbital decompression in Graves ophthalmopathy for improvement of vision.

Graves ophthalmopathy can result in progressive visual loss. Four patients with deteriorating vision despite steroid therapy and/or radiotherapy underwent three-wall orbital decompression through an extended subciliary incision for the preservation of vision. The authors evaluated the visual outcome and morbidity after three-wall orbital decompression for patients with Graves ophthalmopathy. Visual acuity improved for all patients without any major complications in the short-term postoperative period (4 weeks), and visual acuity maintained or improved during the follow-up period. The authors conclude that three-wall orbital decompression can be effective in improving the vision of patients with Graves ophthalmopathy whose vision failed to improve with conservative therapy.

Adult↗
PubMed1986

Differential effects of various causes of deafness on the eyes, refractive errors, and vision of children.

A retrospective study of oculovisual assessment records of the population of three Ontario schools for deaf children assessed the differential effects of various causes of deafness on the prevalence of vision anomalies. Inherited deafness (ID) appears to be associated with the fewest visual anomalies. Congenital rubella (CR) had the greatest prevalence and was associated with the broadest spectrum of ocular and visual problems. It appears to have a significant effect on corneal curvature as well as being associated with anomalies of other organ systems. Children who had had CR, neonatal sepsis (NS), and Rh incompatibility (Rh) all showed higher rates of strabismus and amblyopia. Those who were deaf from meningitis (MEN) or NS showed a tendency to be more hyperopic, whereas the sample with Rh showed a trend toward myopia. The CR children had the broadest range of spherical refractive errors of all the causes of deafness. Children in schools for the deaf are generally those with substantial or profound hearing loss and thus are more likely to have an accompanying vision impairment. Knowledge of the effect on vision of the causes of deafness should aid practitioners in identifying and detecting similar effects on vision when mild or moderate deafness does not require a child's attendance at schools for the deaf.

Child↗
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↗
PubMed2005

Learning prosthetic vision: a virtual-reality study.

Acceptance of prosthetic vision will be heavily dependent on the ability of recipients to form useful information from such vision. Training strategies to accelerate learning and maximize visual comprehension would need to be designed in the light of the factors affecting human learning under prosthetic vision. Some of these potential factors were examined in a visual acuity study using the Landolt C optotype under virtual-reality simulation of prosthetic vision. Fifteen normally sighted subjects were tested for 10-20 sessions. Potential learning factors were tested at p < 0.05 with regression models. Learning was most evident across-sessions, though 17% of sessions did express significant within-session trends. Learning was highly concentrated toward a critical range of optotype sizes, and subjects were less capable in identifying the closed optotype (a Landolt C with no gap, forming a closed annulus). Training for implant recipients should target these critical sizes and the closed optotype to extend the limit of visual comprehension. Although there was no evidence that image processing affected overall learning, subjects showed varying personal preferences.

Adolescent↗
PubMed2005

Assessment of age-related maculopathy using subjective vision tests.

This paper reviews non-standard, clinical vision tests that may be used to detect the earliest visual loss in age-related maculopathy (ARM), before fundus changes are detected. We recommend a clinical test battery for all patients aged 60 years and older, comprising low luminance/low contrast (SKILL) VA or low contrast VA, desaturated D-15 colour vision assessment, flicker perimetry, glare recovery and dark adaptation if possible, together with conventional assessments of case history, ophthalmoscopy and high contrast visual acuity (VA) for the detection and diagnosis of ARM. Reading rate is also discussed as a potential indicator of early visual loss. For monitoring the progressive visual loss in age-related macular degeneration (AMD) and determining the requirements for optometric vision rehabilitation, we recommend more conventional clinical vision tests of distance and near visual acuity, reading rate, the effects of varying illumination and a functional central visual field assessment.

Color Perception↗
PubMed2006

Into the twilight zone: the complexities of mesopic vision and luminous efficiency.

Of all the functions that define visual performance, the mesopic luminous efficiency function is probably the most complex and hardest to standardise or model. Complexities arise because of the substantial and often rapid visual changes that accompany the transition from scotopic to photopic vision. These are caused not only by the switch from rod to cone photoreceptors, but also by switches between different post-receptoral pathways through which the rod and cone signals are transmitted. In this review, we list several of the complexities of mesopic vision, such as rod-cone interactions, rod saturation, mixed photoreceptor spectral sensitivities, different rod and cone retinal distributions, and the changes in the spatial properties of the visual system as it changes from rod- to cone-mediated. Our main focus, however, is the enormous and often neglected temporal changes that occur in the mesopic range and their effect on luminous efficiency. Even before the transition from rod to cone vision is complete, a transition occurs within the rod system itself from a sluggish, sensitive post-receptoral pathway to a faster, less sensitive pathway. As a consequence of these complexities, any measure of mesopic performance will depend not only on the illumination level, but also on the spectral content of the stimuli used to probe performance, their retinal location, their spatial frequency content, and their temporal frequency content. All these should be considered when attempting to derive (or to apply) a luminous efficiency function for mesopic vision.

Adaptation, Ocular↗
PubMed2004

Psychometric properties of the Veterans Affairs Low-Vision Visual Functioning Questionnaire.

PURPOSE: To describe psychometric properties of a self-report questionnaire, the Veterans Affairs (VA) Low-Vision Visual Functioning Questionnaire (LV VFQ-48), which was designed to measure the difficulty visually impaired persons have performing daily activities and to evaluate low-vision outcomes. METHODS: The VA LV VFQ-48 was administered by telephone interview to subjects with visual acuity ranging from near normal to total blindness at five sites in the VA and private sector. Rasch analysis with the Andrich rating scale model was applied to difficulty ratings from 367 subjects, to evaluate measurement properties of the instrument. RESULTS: High intercenter correlations for item measure estimates (intraclass correlation coefficient [ICC]=0.97) justified pooling the data from these sites. The person measure fit statistics (mean square residuals) confirm that the data fit the assumptions of the model. The item measure fit statistics indicate that responses to 19% of the items were confounded by factors other than visual ability. The separation reliabilities for pooled data (0.94 for persons and 0.98 for items) demonstrate that the estimated measures discriminate persons and items well along the visual ability dimension. ICCs for test-retest data (0.98 for items and 0.84 for persons) confirm temporal stability. Subjects used the rating categories in the same way at all five centers. Ratings of slight and moderate difficulty were used interchangeably, suggesting that the instrument could be modified to a 4-point scale including not difficult, slightly/moderately difficult, extremely difficult, and impossible. Fifty additional subjects were administered the questionnaire with a 4-point scale to confirm that the scale was used in the same way when there were four rather than five difficulty ratings. CONCLUSIONS: The VA LV VFQ-48 is valid and reliable and has the range and precision necessary to measure visual ability of low-vision patients with moderate to severe vision loss across diverse clinical settings.

Activities of Daily Living↗
PubMed2005

Vision and quality of life: the development of a utility measure.

PURPOSE: To identify the content for a vision and quality of life-related utility measure (Vision Quality of Life Index [VisQoL]) for the economic evaluation of eye care and rehabilitation programs. METHODS: Focus groups of the visually impaired elicited key concepts. Based on these and previous research, 33 items were generated. These were administered to visually impaired adults (n = 70) and a representative sample of unimpaired adults (n = 86). The item bank was reduced through examination of item properties, exploratory factor (EFA), item response theory (IRT), and structural equation modeling (SEM) analyses. The resultant model was confirmed through administration to a second sample of participants. RESULTS: Focus group themes included physical well-being, social well-being, independence, self-actualization, emotional well-being, and planning and organization. Poorly performing items were eliminated on basic psychometric properties, including failure to discriminate. Next, EFA loadings were used to select items. Twelve items survived. To minimize redundancy, IRT analysis and SEM reduced the VisQoL item pool to six items (Cronbach alpha = 0.88). To confirm this model, these items were then administered to an additional 218 participants; 35% with a vision impairment. A pooled SEM analysis showed the model to have very good fit properties (root mean square error of approximation [RMSEA] = 0.000). A preliminary test of the model against visual acuity showed a significant monotonic relationship. CONCLUSIONS: The short 6-item VisQoL has excellent psychometric properties as a simple summative instrument. It can be used in its present state as a condition-specific outcome measure for the evaluation of healthcare interventions for the visually impaired. The descriptive model is also suitable for generating utility values for the economic evaluation of vision-related programs and services.

Adult↗
PubMed1998

[Computer-based determination of red/green color vision defects].

A commonly used method of investigating colour vision, that is, the ability of the human visual system to discriminate colours, is based on the use of isochromatic colour plates, such as those used in the Ishihara test. The present paper describes a new computer-based method of determining red/green colour vision deficiencies. The method involves the presentation of Ishihara colour plates on a computer monitor. It has been verified experimentally that, despite the differences between the spectral emission of the computer screen and the daylight reflected by the Ishihara plates, the method is capable of distinguishing between subjects with from those without colour vision deficiencies. For screening purposes, the use of a reduced number of plates is suggested. This suggestion makes use of nine instead of 14 plates, and the criterion of two incorrectly recognized plates to determine a colour vision deficiency.

Adult↗