Preservation of vision or prevention of blindness?
Explore the source record for details and available documents.
Blindness↗
SEARCH · Search PubMed
Results for “Vision Screening”
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.
Visual complaints from healthy children.
It is common for healthy children with specific visual complaints to be seen for eye examinations. After a complete eye examination has ruled out pathologic conditions as the cause of these complaints, it is appropriate for the clinician to explore the possibility that normal entoptic or physiologic visual phenomena might have provoked the child's report of vision problems. Some of these normal visual experiences are frequent causes of children's complaints of vision problems, such as physiologic diplopia, relaxation of the near synkinesis during reading, and vitreous body floaters. Some complaints are common, even though the underlying entoptic or physiologic phenomenon may be speculative or obscure, such as the report that objects look bigger or smaller than they actually are. When the clinician encounters such situations, the parents and the child will be much more satisfied by an explanation of the normal system anatomy and physiology than by the simple reassurance that everything is all right.
Accommodation, Ocular↗
Threshold visual acuity testing of preschool children using the crowded HOTV and Lea Symbols acuity tests.
PURPOSE: To compare the testability and threshold acuity levels for very young children on the crowded HOTV logMAR distance visual acuity test presented on the BVAT apparatus and the Lea Symbols logMAR distance visual acuity chart. METHODS: Subjects were 87 Head Start children from age 3 to 3.5 years. Testing consisted of binocular pretraining at near using a lap card as needed, binocular pretraining at 3 m, and threshold testing for each eye. The testing procedure, adapted from the Amblyopia Treatment Study, presented optotypes until the child was unable to correctly name or match three of three or three of four optotypes of a given size. Threshold acuity was the smallest size for which at least three optotypes were correctly identified. RESULTS: Both near and distance pretraining were completed by 71% of children for HOTV and by 75% for Lea Symbols (P =.39). The distribution of threshold acuities differed between the two tests. For the 69 eyes of 53 children who were successfully tested with both optotypes, results from the crowded HOTV acuity test were on average 0.25 logMar (2.5 lines) better than those from the Lea Symbols acuity test (P <.001). CONCLUSIONS: The proportion of children between 3 and 3.5 years of age whose monocular visual acuity could be assessed was high and was similar for the two charts tested. Crowded HOTV acuity results were better on average than results using Lea symbols. The different formats of the two tests may explain the observed differences in threshold acuity level.
Amblyopia↗
The impact of visual impairment and use of eye services on health-related quality of life among the elderly in Taiwan: the Shihpai Eye Study.
To evaluate the effect of impaired vision on health-related quality of life (HRQoL), the authors administered the Medical Outcomes Survey Short-Form 36 (SF-36) to the elderly in a metropolitan Taiwanese community and assessed their visual impairment status. A structured questionnaire was used for door-to-door data collection. Interviewers also collected information on demographics, medical history, and HRQoL. Those who were interviewed were invited to the study hospital for a detailed eye examination. An eye examination, including presenting visual acuity and best-corrected visual acuity, was conducted by ophthalmologists. Presenting visual acuity and best-corrected visual acuity were measured in the better eye. Impaired vision was defined as presenting visual acuity in the better-seeing eye worse than 6/12 (or 20/40) and was used to evaluate the correlation to HRQoL. A total of 1361 subjects at least 65 years of age participated in both the interview and eye examination. Internal-consistency and test-retest reliability of the eight scales were high. Based on the separate multiple regression model, after controlling for all other covariates, subjects in contact with vision services offered by an ophthalmologist had more positive scores on general health perceptions (beta = 4.29; p < 0.001), vitality/energy (beta = 2.73; p < 0.001), and mental health (beta = 2.06; p = 0.01). Impaired vision was associated with significantly lower scores in physical functioning (beta = -3.62; p < 0.001) and social functioning scales (beta = -3.25; p = 0.015). The findings suggest that visual impairment is associated with lower quality of life and use of eye care services is associated with higher quality of life.
Aged↗
Vision care requirements among intellectually disabled adults: a residence-based pilot study.
Intellectually disabled adults have an high incidence of visual problems and they are often unable to communicate their visual difficulties. At Lennox Castle and Waverley Park Hospitals, vision care is through referral by medical and nursing staff to designated optometrists and ophthalmologists. This practice has provided a good service when visual difficulties are noticed. The vision care requirements of all residents had not been comprehensively assessed and a new interdisciplinary procedure developed at Waverley Park Hospital had drawn attention to the fact that only 11% had been offered vision assessment within the previous 5 years. In this study, 63 residents without specific referral received a comprehensive visual and medical assessment. The residents ranged from age 20 to 85 years and included the full range of disabilities. Objective assessments, ophthalmoscopy and retinoscopy were generally successful for all levels of disability. Visual acuity and visual fields were tested using methods suitable for nonverbal subjects. Success rates for these subjects were generally good, except in the profoundly disabled group where less than 30% were able to respond. A high prevalence of visual impairment, refractive error, squint and other ocular conditions was found. Visual impairment was most common in the severe and profoundly disabled groups because of optic nerve or cortical dysfunction. New spectacles were recommended for 23 residents (seven others had adequate correction). Nine residents were referred for ophthalmologic consultation, mainly for cataract. Three required monitoring for visual conditions. Thirty-one residents (49%) required no immediate action beyond documentation of the visual status. This study has shown a high prevalence of visual difficulties which were not previously detected. Routine biennial vision assessment of all residents is recommended to allow timely intervention to correct vision problems, and also to provide the necessary information about vision to plan appropriate programmes of activity.
Adult↗
[Visual acuity testing in pre-school children: a comparison between the Sheridan-Gardiner test and the Räder (broken wheel) test].
PURPOSE: To evaluate the comparability between the well-established Sheridan-Gardiner test (SGT) and a new type of visual acuity test, called the Räder test (RT = broken wheel test) in pre-school children, and to compare test durations of these infant visual acuity tests. SUBJECTS AND METHODS: The RT consists of 16 cards with visus values of 0.16, 0.2, 0.25, 0.3, 0.5, 0.6, 0.8 and 1.0. One pair of cards depicting a car is used for testing. On one of the cards the car has intact wheels, on the other the wheels are incomplete, symbolized by a Landolt ring. The child must indicate, at a viewing distance of 3 meters, which of the wheels is incomplete. The SGT consists of seven visus plates: 5/60, 5/36, 5/24, 5/18, 5/12, 5/9 and 5/6. Each level is tested with one letter and can be repeated by the presentation of a further letter (A, H, O, T, U, V, X). The examination distance is 5 meters. The child must indicate, with reference to a card depicting all seven symbols, which letter the examiner is showing. The SGT and RT were performed in a randomized cross-over sequence in 30 children (20male, 10 female) of pre-school age (from 2 years up to and including the age of 5 years, mean 3.4 years +/- 0.77 SD, median 3.0 years). In all cases, the right eye was examined first. Examination duration was assessed for each acuity test, and for each eye separately with a stopwatch. The instruction time was not considered. The possible visual acuity values of both bests were replaced by a unified scale of visual acuity levels (ranging from 1 to 10). A difference of at least two levels was considered as relevant. The results were compared by means of the sign test at a significance level of 0.05. RESULTS: In particular, for higher visual acuity levels there were considerable differences, with SGT generally showing better results than RT: in 11 of 29 children, in both eyes RT values turned out to be at least 2 lines better than those obtained with SGT. The contrary situation, i. e., favoring SGT by more than 2 lines compared to RT, never occurred. According to the sign test, these differences were significant (p < 0.001). SGT revealed also clearly better visual acuity levels in those 22 children out of the 30, who exhibited differences by 2 lines or more in at least one eye (p < 0.001). The examination procedure with RT revealed problems in making the required directional decisions, especially between 2 and 4 years of age. This might interfere with the test interpretation and lead to distortion of the RT results. Total examination duration did not differ considerably between SGT (1.6 to 5.8 minutes, median 3.0 minutes) and RT (1.6 to 9.4 minutes, median 4.6 minutes), respectively. CONCLUSIONS: The Sheridan-Gardiner test generally shows better results than the new Räder (RT = broken wheel) test in pre-school children. Problems in making the required directional decisions may interfere with RT in this age group.
Bias↗
[Visual object and space perception battery: normal values for children from 8 to 12].
BACKGROUND: Diagnostics of central visual perception is a relevant branch of developmental medicine and neuropsychological diagnostic efforts of morphological or functional lesions of the brain. However, no assessment battery for testing the central-visual perception in German-speaking children exists. PROBANDS AND METHOD: In 30 children, aged 8 - 12 years, the Visual Object and Space Perception Test Battery (VOSP) was applied. RESULTS: The group values were documented as standard values. Instructions and aims of the tests were well comprehended by the children. CONCLUSION: The VOSP is well applicable to children. Further studies examining correlation between the VOSP and clinical data are warranted.
Child↗
[Reference values in vision development of infants with clinical use of the Teller Acuity Cards].
BACKGROUND: Using Teller Acuity Cards (TAC) for clinical visual testing, the question arose how our measurements fitted in the different standard tables of the producer's hand-book. In addition, we wanted to investigate how reliable the measurements of newborn and infants were and what the examination success rate under clinical conditions was. METHODS: At the paediatric clinic of the University of Erlangen, we tested the binocular grating acuity of 98 infants up to the age of one year, using the complete set of Teller acuity cards. In addition, 41 of the children underwent a monocular vision test. RESULTS: 1. Theoretical: At first we calculated conversion data for our card set. Using this conversion scale from cy/cm in cy/deg and the corresponding vision equivalent we produced our own standards for the development of grating acuity up to the age of one year. 2. Clinical: In 3-5 min per clinical examination we could determine for 90.8% of the patients a vision equivalent. The reliability of the results was age dependent and was at its best at the age of 5-11 months. The reliability was also very dependent on the duration of the test and the number of test runs. This resulted in a limited card choice for each age group.
Age Factors↗
[The Freiburg Stereotest. On assessment of stereovision in automobile driver examination].
BACKGROUND: The "Freiburg Stereotest" is a new instrument where disparate pictures are generated by a computer and displayed on one single high resolution video monitor. In the present work, the Freiburg Stereotest was used to check the stereo qualification for certain categories of driver's licence. For this purpose, a determination of the smallest detectable disparity is not reasonable. Rather, it should be checked whether or not a certain disparity, usually well above threshold, is recognized with a sufficient reliability. We have chosen a disparity of 100 arcsec; this value is considered to be an acceptable requirement for certain categories of driver's licence. SUBJECTS AND METHODS: 6 strabismic subjects were examined binocularly and 10 normal subjects were examined both binocularly and monocularly. Two targets ("busses"), side by side and different in depth by a disparity of 100 arcsec, were presented 78 times and, in a two-alternative forced-choice procedure, a minimum of 66 hits was required to pass the test. Monocular cues were excluded by a systematic variation of the lateral distance between the two targets. RESULTS: The strabismic subjects and the monocularly occluded normal subjects reached random scores only. With both eyes open, 8 of the 10 normal subjects reached scores near 100%, while 2 of them passed the test only when the lateral distance between the two targets was 15 minarc or less. For a lateral distance between the two targets of more than 15 minarc, these 2 subjects showed a learning effect. CONCLUSIONS: The Freiburg Stereotest allows to determine with statistical significance whether or not a proband can recognize a certain disparity which may be required for a driver's licence.
Adult↗
Vision in Alzheimer's disease.
In order to assess vision in Alzheimer's disease (AD) and related disorders, gerontologists must use tests that make minimal cognitive demands on the subject. Using such tests, we have found a pattern of deficits in color discrimination, stereoacuity, contrast sensitivity, and backward masking that differs from that seen in healthy elderly individuals. Impaired vision predicts deficient performance of subjects with AD on numerous tests of cognition, underscoring the importance of understanding visual changes in this population.
Aged↗
The Night Vision Threshold Test (NVTT): a simple instrument for testing dark adaptation in young children.
It is estimated that 41 per cent of the population aged under 5 in the developing world has an inadequate vitamin A dietary intake resulting in increased morbidity and mortality. Half a million children go blind each year as a result of vitamin A deficiency. Thirteen and a half million have night blindness, the first sign of vitamin A deficiency. Unfortunately, there is no simple, sensitive and inexpensive means to identify the child who has marginal levels of vitamin A and thus institute means to prevent their development of severe deficiency. A low cost, simple, easy-to-use instrument designed to detect a young child's ability to adapt to darkness was tested in children admitted to the Mwanamugimu Nutrition Unit at Makerere Medical School in Kampala, Uganda. Despite the severe degree of malnutrition found in these children, Night Vision Threshold Test results and serum retinol levels were related (r = 0.41, p < 0.05). Further efficacy trials for this instrument are planned at community sites in Nepal.
Adaptation, Ocular↗
Sensory impairment in older adults: part 2: Vision loss.
A decline in vision occurs naturally with age; more severe impairment can result from medical conditions such as age-related macular degeneration, cataracts, glaucoma, and diabetic retinopathy. Nurses can pick up signs of visual impairment and suggest certain environmental modifications to prevent injury, such as keeping floors free of clutter and rooms well lit. Although assistive technologies such as optical devices, magnifiers, telescopes, and electronic magnification can help, some forms of impairment, such as that caused by cataracts and uncorrected refractive error, can be corrected.
Aged↗
Juvenile retinal detachment.
We feel that the management of juvenile retinal detachment can best be improved by earlier diagnosis. School vision-screening tests should be encouraged, and long-term followup of patients with high myopia, aphakia, and retrolental fibroplasia should be practiced. The peripheral retina should be examined in all traumatized eyes since delayed detachment is the rule. When retinal breaks are found in high-risk eyes, in our opinion, prophylactic treatment is indicated.
Adolescent↗
Sight-screener calibration study.
Explore the source record for details and available documents.
Calibration↗
Effects of induced hyperopia.
Hyperopia of 1.00, 1.50, and 2.00 D was induced in 42 subjects by means of concave lenses. A significant decrease in performance on a standard intelligence test occurred with the highest-power lenses. Symptoms induced indicate that the results are applicable to hyperopia. Prescriptions and vision screening criteria for hyperopia are indicated.
Adolescent↗
Static retinoscopy results with and without a fogging lens over the non-tested eye.
This study addressed the question: "Should both eyes be fogged during static retinoscopy?" Static retinoscopy measures were taken on young patients. (N = 50; mean age = 9 years, 4 months). Outcomes revealed no differences except with hyperopic patients, where the lack of a fogging lens over the partner eye resulted in a significant underestimate (p less than .001) of the refractive status. This argues against the use of a lens bar for retinoscopy especially in vision screening programs involving young children.
Adolescent↗
Quantitative photorefraction using an off-center flash source.
When an eye is refracted by "eccentric photorefraction" with a flash source off-centered from a camera lens, a crescent of light is formed in the margin of the pupil. The size of the crescent varies directly with the eye's refractive error. This photographic method has been used in vision screening studies of young children where the appearance of a crescent indicated that the refractive error was above a certain threshold. Usually quantification of the refraction could not be achieved by the photorefractor but relied upon subsequent testing using retinoscopy. My research aimed to expand eccentric photorefraction so as to enable it to provide quantification of the eye's refractive error. This was achieved by varying the eccentricity of the flash source from the camera lens and then calibrating the instrument over a large range of refractive errors. The calibration modified a previously derived optical relation which defined the eye's refractive error in terms of the eccentricity of the source for a given pupil size. Eccentric photorefraction of 26 infants and children aged 7 to 48 months showed a good correlation with retinoscopy (r = 0.82). It is concluded that this method would be complementary to other photorefractive methods (e.g., isotropic) particularly as it is able to measure a large range of refractive errors once the astigmatic meridians of the eye are known.
Calibration↗
Monocular accommodative facility testing reliability.
Recently, concern has been expressed about accommodative facility testing reliability, especially for subjects rated initially as failing. Our study evaluated an extended testing period's effect on reliability. Subjects, ages 8 to 12 years, were tested for an initial 1-min period; to identify two groups; high fails (greater than 6, but less than 11 cpm, N = 30) and low fails (less than 6 cpm, N = 30), and then for an additional 2 min. Mean rate change analysis showed both high and low fail groups improved their accommodative facility over extended testing (1.29 and 0.87 cpm, respectively), although no significant difference was found between the groups. In contrast, test-retest correlations indicate a higher reliability for the baseline rates among low fail (r = 0.720) as compared to high fail (r = 0.402) subjects. The difference between groups became more evident when diagnostic classification was monitored over the 3-min testing period, with 73.3% of the low fails remaining low fails, and 43.4% of the high fails reached the pass criterion. The 1-min testing method appears more reliable if the initial rate is less than 6 cpm. For patients whose initial rate is between 6 and 11 cpm, extended testing (1 additional min) may be needed to arrive at an accurate diagnosis, especially if presenting symptoms are absent.
Accommodation, Ocular↗