Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “VISION”

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 667 records · Page 37Linked to original sources
PubMed2004

Changing demographics and vision restrictions in civilian pilots and their clinical implications.

BACKGROUND: The Federal Aviation Administration guides policy decisions through the study of medical pathologies and visual disorders common to aviators. The purpose of this study is to examine demographic statistics present in the civil airman population, including vision restrictions, and their relevance to the clinical care of aviators. METHODS: Medical certification data were extracted from FAA publications and databases for all civil airmen who were active on December 31st of each year from 1976 to 2001. Frequency and medical restriction data were delineated into 5-yr increments and analyzed to identify population trends for the 25-yr study period. RESULTS: Although the total number of pilots has decreased over the study period (-17%), the population of male and female airmen holding first-class medical certificates has grown by 119% and 1,241%, respectively. The percentage of pilots > or = 40 yr of age has increased by 17%, and the average age rose from 36.8 to 42.3 yr. Additionally, the increase in near vision restrictions (13%) was more than double that of distant vision restrictions (6%) during the study period. As of 2001, 92% of all medical restrictions were vision related. CONCLUSION: The results of this study indicate that the increasing number of first-class certificate holders, gender-specific vision problems for female pilots, and the age-related changes in refractive error may present new challenges for eye-care practitioners tasked with advising aviators concerning the proper choice of refractive correction.

Adult↗
PubMed1989

[Comparison of the Kolling distance vision stereo-test with current stereo-test procedures].

A new type of stereotest for distant vision (after Kolling) is compared with established stereotests for distant (different types of Zeiss Polatest) and near vision (Titmus, TNO, Lang tests) in a total of 203 patients. The Kolling test is based on the three-rod method in accordance with Helmholtz. The apparatus does not require separation of the visual input of the two eyes. This new stereotest is practice-oriented, quick, easy to understand and gives reliable and reproducible results. The test cannot be completed successfully with monocular viewing, if the head is fixed. The results show a good correspondence between the Kolling test and the Zeiss Polatest using disparate outlined figures. The Zeiss Polatest using random-dot patterns turned out to have the strictest criteria for this purpose of all stereotests. Interestingly enough, subjects performed much better in stereotests for near vision (Titmus, TNO tests) than in those for distant vision (Kolling test, different types of Zeiss Polatest). The widespread use of stereotests of near vision in driving tests is therefore problematic.

Adolescent↗
PubMed1989

Predictors of functional success in telescopic spectacle use by low vision patients.

Telescopic spectacles can theoretically improve function of low vision patients by enlarging retinal images. However, unintended head movement may produce sufficient instability of enlarged retinal images to negate the visual benefit. We investigated this phenomenon as a cause of failure in 38 low vision patients who had previously attempted use of telescopic spectacles. Patients underwent evaluation of the vestibulo-ocular reflex, visual-vestibulo-ocular reflex, head stability in the pitch and yaw axes, and sensitivity of magnified visual acuity to head motion. Although it was impossible to distinguish successful from unsuccessful telescopic spectacle users by means of clinical or historical data, multiple logistic regression analysis was used to derive a useful predictive function based on measurements of sensitivity of magnified vision to head motion, and head instability in the pitch axis. Predictive performance was found to be superior to conventional clinical judgement. These findings support the hypothesis that retinal image stability is important to functional vision, and suggest that head-stabilizing strategies may improve function with telescopic spectacles in certain low vision patients.

Adult↗
PubMed1987

Normal and defective colour vision in large field.

Colour vision is spatially organized. A light stimulus has to strike spectrally different photoreceptors, covering the center and surround of the receptive field of a colour opponent retinal ganglion cell. Otherwise, no colour opponent processing of signals will occur. Vice versa, spatial summation provided by a large field may compensate for weak opponency. This happens not only in congenital, but also in acquired colour vision defects, when opponency is weakened secondary to a reduced receptoral input. Large field colour vision in Daltonians. Large field red-green opponency is a common phenomenon in patients fitting into the criteria of protanopia and deuteranopia. The difference between small and large field colour vision can be demonstrated by the "projection anomaloscope". At a 30 degrees test field, many anopes behave like the respective anomalous observers. The majority of anopes appear to have some "forbidden cones" at their retinal disposal. So, anomaly and anopia share a common photochemical basis, i.e., the anomalous pigment. However, in anopes, the number of those anomalous cones is extremely small. Therefore, anopic observers usually need a very large amount of spatial summation to arrive at a well defined match of the projection anomaloscope. In protanopes the large field match in our experiments was always a protanomalous one, with the exception of one large field protanope. In deuteranopes, however, there was no such constant behaviour in large field matching. We found deuteranomalous matches as well as matches in the vicinity of the normal mid-match point. Contrary to this behaviour of anopes anomalous observers do not significantly alter their matching pattern irrespectively of whether small (1 degree) or large (30 degrees) test fields are used. So-called peripheral colour blindness of normal observer. Results of classical colour perimetry reveal a dichromatism of the intermediate and a monochromatism of the extreme retinal periphery of the normal observer. These results appear to contradict the common everyday experience of colour constancy throughout the visual field. But a threshold correlation of colour constancy at different retinal exentricities can be demonstrated by recording spectral increment thresholds with test field diameters increasing towards the retinal periphery. So, the colour blindness of the retinal periphery is merely an area phenomenon. It can be overcome by large field observation, rendering spatial summation. Congenital achromatopsia. Remnants of colour vision can be demonstrated in many achromats.(ABSTRACT TRUNCATED AT 400 WORDS)

Color Perception↗
PubMed1996

Comparison of the standard pseudoisochromatic plates--Parts 1 and 2--As screening tests for congenital red-green color vision deficiencies.

BACKGROUND: The Standard Pseudoisochromatic Plates-Part 2 (SPP-2) are designed primarily as a screening test for acquired color vision deficiencies. However, results from several studies suggest that the SPP-2 may also be effective as a screening test for congenital red-green color vision defects. METHODS: In this study, the screening effectiveness of the SPP-2 was compared with the Standard Pseudoisochromatic Plates-Part 1 (SPP-1) to determine whether clinicians must use both tests: the SPP-1 to screen for congenital color vision defects and the SPP-2 to screen for acquired color vision defects. RESULTS: The results showed that, when using the recommended scoring criterion for the SPP-1, the SPP-2 test is slightly more sensitive in detecting congenital red-green defects. CONCLUSIONS: Clinicians can use the SPP-2 to screen for both congenital and acquired color vision defects.

Adolescent↗
PubMed1996

Accommodative and binocular vision disorders associated with video display terminals: diagnosis and management issues.

BACKGROUND: With the rapid computerization of the workplace, school and home office, it is likely that a vast majority of Americans will be using computers for significant amounts of time in the near future. Research has demonstrated a high prevalence of accommodative and binocular vision disorders in symptomatic VDT users, which underscores the importance of the assessment and management of accommodation and binocular vision for patients working with computers. METHODS/RESULTS: This paper presents a simplified approach for the diagnosis and management of accommodative and binocular vision disorders in VDT users. The emphasis is on modifications of the traditional examination routine to make the assessment as sensitive as possible to the vision problems associated with VDT use. CONCLUSIONS: To meet the needs of symptomatic VDT users, optometrists must perform a comprehensive assessment of accommodation and binocular vision. The use of appropriate testing, when combined with attention to the environmental factors associated with VDT use, will enable optometrists to understand the reasons for symptoms and design an effective treatment program.

Accommodation, Ocular↗
PubMedDate not supplied

The step phenomenon in the recovery of vision with spinal manipulation: a report on two 13-yr-olds treated together.

OBJECTIVE: To discuss the immediate increment of improvement in vision that occurs when the spine is manipulated. CLINICAL FEATURES: Two juvenile patients (13-yr-old female cousins) were found to have constricted visual fields and diminished visual acuities. INTERVENTION AND OUTCOME: Spinal manipulation was associated with recovery of normal vision over seven treatment sessions. It was noted that significant improvement in vision occurred immediately after the spinal manipulation treatments. Full recovery of vision was attained by series of these steps. In addition, both patients reported significant constitutional benefits after the treatment in addition to the improved vision. CONCLUSION: The change in visual function immediately related to spinal manipulation has been described as the "step phenomenon." The step phenomenon raises questions about the nature of the condition that may be treated by spinal manipulation and the method of action of the treatment. A vascular hypothesis is mentioned that could explain these events. The consistent occurrence of the step phenomenon indicates that spinal manipulation may have an effect on brain function.

Adolescent↗
PubMed1998

Clinical application of the new civil airman vision standards and certification procedures.

INTRODUCTION: The final rule revising the civil airman medical standards became effective September 16, 1996. The purpose of this study was to review changes in the vision standards and procedures and how they relate to the clinical optometrist. METHODS: Revision of Airman Medical Standards and Certification Procedures and Duration of Medical Certificates; Final Rule, (14 CFR, Parts 61 and 67) and the Guide for Aviation Medical Examiners, published by the Federal Aviation Administration's Office of Aviation Medicine, were reviewed, and those parts pertaining to the clinical optometrist were summarized. DISCUSSION: The uncorrected distance visual acuity standards for first- and second-class airmen have been deleted. New equivalent near-vision standards were established for all classes of airmen. A major change--for pilots > or = 50 years of age--was the addition of an intermediate vision requirement of 20/40 or better at 32 inches for both first- and second-class medical certificate holders. Although the third-class medical certificate is still valid for 24 months after the date of examination for those > or = 40 years of age, the certificate is now valid for 36 months for those < 40 years of age. CONCLUSION: The new vision standards primarily affect the elderly pilot. Ophthalmic considerations in the application of the new vision standards are reviewed.

Adult↗
PubMedDate not supplied

Blindness and low vision in leprosy patients in Sichuan Province, China.

The acuity of vision of 2145 leprosy patients was examined. Twenty-six patients had bilateral blindness and 80 had diminution of vision bilaterally, according to WHO's standard. The vision disability rate was 4.94%. In addition, 136 patients (6.34%) had blindness or low vision involving one eye. The causes of blindness and low vision were leukoma and corneal ulcer.

Adult↗
PubMed1989

Binocular vision, age and symptoms.

Changes with age in heterophoria, associated heterophoria, fixation disparity and stereopsis for near vision were investigated in a sample of 187 subjects (age range from 10 to 65 years) divided into six age groups. With increasing age, heterophoria, associated heterophoria and fixation disparity increased in the exo-direction. No change in stereopsis was found. A comparison with visual symptoms for near vision indicated a relationship between symptoms and the magnitude of fixation disparity and associated heterophoria for all age groups, but no relationship was found between the presence of symptoms and heterophoria measurement. No relationship between the presence of symptoms and the central slope of the forced vergence fixation disparity curve was found. These findings suggested that neither the measurement of heterophoria nor the forced vergence disparity curve are appropriate tests in the assessment of binocular vision anomalies. However, fixation disparity and associated heterophoria are related to binocular problems for near vision in all age groups.

Adolescent↗
PubMed2002

Effect of depression on vision function in age-related macular degeneration.

OBJECTIVES: To report the prevalence rate of depression in older patients with recent vision loss due to age-related macular degeneration (AMD) and to describe the effect of depression on self-reported vision function during 6 months. METHODS: Prospective cohort study of 51 older patients with recent-onset bilateral AMD attending the Retina Clinic of Wills Eye Hospital, Philadelphia, Pa. Main outcome measures included the Center for Epidemiological Studies Depression Scale, visual acuity, Functional Vision Screening Questionnaire, Chronic Disease Score, and Community Disability Scale. RESULTS: Seventeen patients (33%) were depressed at baseline and had worse visual acuity (P =.04) and greater levels of vision-specific (P =.03) and general (P =.002) physical disability than nondepressed patients. The correlations of Center for Epidemiological Studies Depression Scale score with visual acuity and visual-specific disability, however, were not significant after controlling for general physical disability. An increase in depressive symptoms over time predicted decline in self-reported vision function independent of changes in visual acuity or medical status (P<.05). CONCLUSIONS: The prevalence and disabling effects of depression in older patients with AMD are substantial. Recognizing that depression is a treatable disorder that exacerbates the effects of AMD will lead to improved outcomes. Innovative interventions to prevent or treat depression in specialty eye clinics are possible.

Aged↗
PubMed2005

Experimental implantation and long-term testing of an intraocular vision aid in rabbits.

OBJECTIVE: To develop an intraocular vision aid to provide artificial vision in severely traumatized eyes, where neuroretinal function could be preserved but irreversible anterior segment opacification resulted in blindness. METHODS: The basis of an intraocular vision aid is in principle a telemetric circuit to bridge the opaque cornea and to allow for artificial light stimulation of the retina. The visual prosthesis comprises an external high-dynamic range complementary metal oxide semiconductor camera and digital signal processing unit and an intraocular miniaturized light-emitting diode array to project the image onto the retina. For in vivo testing of long-term function and biocompatibility, silicone-encapsulated active photodiodes were implanted in 13 pigmented rabbits and were followed up for up to 21 months. RESULTS: Lens extraction and stable fixation of the device in the ciliary sulcus were successful in all cases. For up to 21 months inductive energy transmission and wireless stimulation of the implants could be maintained. Electrophysiologic data and histology demonstrated a good tissue biocompatibility in the long-term follow-up. CONCLUSION: The results demonstrate the general feasibility and biocompatibility to implant and fixate an intraocular light-emitting diode prosthesis. Inductive energy transmission to the intraocular device and wireless light stimulation are assured in the long term but depend on meticulous water-impermeable encapsulation of the delicate microelectronic components. Clinical Relevance An intraocular vision aid compound system with a high-resolution light-emitting diode matrix might be a future treatment option to restore vision in blind eyes with severe anterior segment disorders.

Animals↗
PubMed2005

Prevalence and burden of self-reported blindness, low vision, and visual impairment in the French community: a nationwide survey.

OBJECTIVE: To estimate the prevalence of self-reported visual impairment and its association with disabilities, handicaps, and socioeconomic consequences. METHODS: A national survey was conducted on a random stratified sample of 359 010 French citizens living in the community; 21 760 subjects were selected at random and 16 945 persons (78%) agreed to further questioning. Four thousand ninety-one randomly selected caregivers were interviewed. Four subgroups of subjects were defined (blind or light perception only, low vision or still have form perception, other visual problems, and no visual problems). These were compared after adjustment for age, comorbidity, and household size differences. RESULTS: The prevalence of blindness was 0.10% and of low vision, 1.94%. Subjects with blindness needed assistance with daily activities more often than subjects with no visual problems; they also needed more house modifications. Many subjects with blindness (46.8%) and subjects with low vision (29.0%) were registered for social allowances. Subjects with blindness had fewer paid activities (4.5%) than subjects with no visual problems (20.7%). Social allowances increased considerably (by 277) between those with low vision and those with blindness. Monthly household incomes were lower (P<.001) for subjects with low vision (1255) and blindness (1587) than for subjects with no visual problems (1851). MAIN OUTCOME MEASURES: Collected data included social demography, home description, household income, handicaps, disabilities, social allowances, and daily activities. CONCLUSION: The results demonstrate associations between self-reported visual impairment and daily living.

Activities of Daily Living↗
PubMed1984

Correlation of color vision deficits and observable changes in the optic disc in a population of ocular hypertensives.

Both glaucomatous cupping and the presence of acquired color vision deficits have been reported to be precursors to the onset of visual field defects in patients with suspected glaucoma. To examine the relationship between early glaucomatous cupping and acquired color vision anomalies, we performed anomaloscope (Pickford-Nicholson) and Farnsworth-Munsell 100-Hue color vision tests in 48 ocular hypertensive eyes with either clinical evidence of early glaucomatous cupping (group 1) or no evidence of glaucomatous cupping (group 2). All patients had normal visual fields, as determined by extensive static perimetry of the central visual field and kinetic perimetry of the peripheral visual field. Although the overall incidence of blue and blue-green color vision anomalies in the ocular hypertensives was comparable with that reported in previous studies, we found no clear association between early glaucomatous cupping and color vision anomalies. The relationship between these two precursors to visual field loss remains unclear.

Adult↗
PubMed1993

Vision change and quality of life in the elderly. Response to cataract surgery and treatment of other chronic ocular conditions.

OBJECTIVE: Evaluation of health care in older populations has increasingly focused on quality of life as a critical outcome of treatment. Vision is assumed to be central to functioning. Data suggest that aging, in itself, is associated with a decline in visual functioning, which, in turn, is related to a decline in physical and mental functioning. Other studies indicate that cataract surgery is followed by significant improvement in vision and visual function. Our objective was to test these assumptions. DESIGN: Prospective study of 1021 patients, consecutively drawn from 76 randomly selected ophthalmologists' offices in three cities. Structured interviews were completed at baseline, 2 months, and 1 year after entry. PATIENTS: Six hundred thirteen patients with cataracts and 408 other ophthalmic patients drawn from the same offices but treated for other chronic ocular disorders. All received refractive services as needed. SETTING: Patients from three cities (Baltimore, Md, St Louis, Mo, and San Diego, Calif) were interviewed once in their homes and twice by telephone. INTERVENTIONS: The study involved the measurement of the effects of usual treatment for cataracts and other degenerative eye diseases. MAJOR OUTCOME MEASURES: Visual, social, and psychological functioning. RESULTS: Within 1 year of treatment, change in visual function was accompanied by significant changes, in the same direction, in quality of life functions: night-time driving, daytime driving, community activities, home activities, mental health, and life satisfaction. In addition, the patients with cataracts showed significantly greater improvement in measures of vision than did the noncataract group. CONCLUSIONS: Regardless of treatment, improvement across quality of life functions occurred when visual function improved. Thus, many types of functional degeneration observed in older populations, attributed to a decline in vision, can be slowed, or even reversed, when visual function is improved. Cataract surgery was effective in improving vision and quality of life functions.

Aged↗
PubMed2003

Orientation and mobility training for adults with low vision.

BACKGROUND: Orientation and mobility (O&M) training is provided to people who are visually impaired to help them maintain travel independence, teaching them new orientation and mobility skills to compensate for reduced visual information. OBJECTIVES: The objective of this review was to assess the effects of orientation and mobility training, with or without associated devices, for adults with low vision. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials - CENTRAL (which contains the Cochrane Eyes and Vision Group trials register) (Issue 3 2002), MEDLINE (1966 to August 2002), EMBASE (1980 to September 2002) and LILACS (September 2002) and the reference lists of articles. SELECTION CRITERIA: We planned to include randomised or quasi-randomised trials comparing orientation and mobility training with no training in adults with low vision. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed the search results for eligibility. MAIN RESULTS: No studies were found that satisfied the inclusion criteria. REVIEWER'S CONCLUSIONS: We could not find any controlled trials on the effects of orientation and mobility training for adults with low vision. As a premise to future trials, orientation and mobility instructors and scientists should reach a consensus and develop valid measures of mobility performance which are both reliable and meaningful to people with low vision.

Adult↗
PubMedDate not supplied

Rehabilitation options for patients with low vision.

Loss of vision has a profound effect on an individual's life. Reduced visual function, whether present at birth or appearing later in life, greatly affects one's perception of useful existence. When medical intervention can no longer restore or maintain a person's functional vision, rehabilitative measures are necessary to enable that person to adjust both physically and psychologically to his or her sensory loss. Rehabilitation for low vision offers visually impaired individuals a renewed independence and productivity that will enable them to rejoin society as active participants. Often patients and healthcare providers are unaware of the rehabilitation options that are available to them. Low-vision devices such as magnifiers and telescopes, as well as counseling and vocational training, are among the available options. Rehabilitation nurses are particularly qualified to identify patients with reduced functional ability and to recommend an appropriate visual assessment that can lead to maximized residual vision.

Ambulatory Care↗
PubMed1982

Oculomotor response to rapid head oscillation (0.5-5.0 Hz) after prolonged adaptation to vision-reversal. "Simple" and "complex" effects.

This study examined long-term (up to 27 days) effects of maintained vision reversal on (i) smooth visual tracking with head still, (ii) oculomotor response to actively, generated head oscillation and (iii) "spontaneous" saccades. Dove prism goggles produced horizontal, but not vertical (sagittal plane), vision reversal. Eye movements were recorded by EOG; head movements by an electro-magnetic search coil. Both visual tracking and saccade dynamics remained unchanged throughout. In contrast, both the ocular response to active head oscillations (goggles off and subject looking at a stationary target) and associated retinal image blur showed substantial and retained adaptive changes, akin to those previously found in the vestibulo-ocular reflex as tested in darkness at 0.17 Hz. However, several addition unexpected results emerged. First, in the fully adapted state smooth eye movements tended to be of reversed phase in the range 0.5-1.0 Hz (in spite of normal vision during tests), but of normal phase from about 2 Hz and above (in spite of negligible visual tracking in this upper range). Second, after permanent removal of the inverting goggles, this peculiar frequency response of the fully adapted state quickly (36 h) reverted to a dynamically simpler condition manifest as retained (2-3 weeks) attenuation of gain (eye vel./head vel.) which, as in control conditions, was monotonically related to frequency. From these two findings it is inferred that the fully adapted state may have comprised two separate components: (i) A "simple element of monotonic and long-lasting gain attenuation and (ii) a "complex", frequency labile, element which could be quickly rejected. Dynamic characteristics of the putative "complex" element were estimated by vectorial subtraction of the "simple" one from that of the fully adapted condition. The outcome suggests that the inferred "complex" condition might represent a predictive element. Two further findings are reported: (i) Substantially different vectors of the adapted response were obtained with normal and reversed vision at 3.0 Hz head oscillation, indicating a novel visual tracking. (ii) During head oscillation in the vesicle sagittal plane (in which vision was not reversed) there was never any image blur, indicating high geometric specificity in the adaptive process.

Acoustic Stimulation↗