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At least 1,423 records · Page 79Linked to original sources

PubMed2001

Exercise-induced visual loss associated with advanced glaucoma in young adults.

PURPOSE: To highlight the phenomenon of exercise-induced visual loss associated with advanced glaucoma and to discuss the possible underlying mechanisms. METHODS: Three young adult patients with congenital or juvenile-onset glaucoma presenting with visual loss which occurred during exercise underwent ophthalmic examination. In 2 cases, visual function parameters, including visual fields (Humphrey full threshold perimetry) were measured before and after exercise. RESULTS: All patients clearly described visual loss during exercise. In the 2 cases in which data were available, significant impairment in central visual acuity and reduced foveal sensitivity and mean deviation on visual field analysis occurred during exercise of mild to moderate intensity with complete or near complete recovery of visual function upon cessation of exercise. CONCLUSION: Young patients with advanced glaucomatous optic neuropathy should be questioned regarding exercise-induced visual disturbance. We hypothesise that a 'vascular steal' is the likely mechanism underlying this phenomenon. Patients should be advised to limit activities which induce their symptoms, and therapeutic measures to promote ocular blood flow should be considered.

Adult↗

PubMed2003

Psychometric performance of the NEI VFQ-25 in visually normal Latinos: the Los Angeles Latino Eye Study.

PURPOSE: To characterize the psychometric performance of the National Eye Institute 25-item Visual Function Questionnaire (NEI VFQ-25) in visually normal Latinos (Mexican Americans). METHODS: The Los Angeles Latino Eye Study (LALES) is a population-based study to assess the prevalence of eye disease and self-reported visual functioning in Latinos aged 40 or more years. Self-reported visual functioning was assessed by using English and Spanish versions of the NEI VFQ-25. Psychometric properties of the NEI VFQ-25, including internal consistency of the subscales and the individual items, were assessed through the Multi-trait Analysis Program-Revised (MAP-R) analysis. Adjusted mean and median subscale scores were compared between English and Spanish speakers to identify any systematic differences. RESULTS: Of the 1917 participants from two census tracts, 1171 participants with no visual impairment were included in this analysis. The mean age of the participants was 52.3 years, 57% of the participants were female, and 67.5% of the participants were Spanish speaking. Median scores for Spanish-speaking participants were significantly lower than those of the English-speaking participants on four subscales: Ocular Pain, General Vision, Vision-Specific Mental Health, and General Health (P < 0.05). Internal consistency for three of eight measurable subscales for the study group was poor (Cronbach alpha < 0.6). CONCLUSIONS: This study reveals psychometric inconsistencies in the NEI VFQ-25 when administered to visually normal Latinos. The difference in mean subscale scores between Spanish and English speakers must be integrated into the development of population norms of visual function. Further detailed psychometric evaluation is needed to determine the validity of this instrument in Latino populations.

Activities of Daily Living↗

PubMed1998

Critical periods and amblyopia.

During the past 20 years, basic science has shown that there are different critical periods for different visual functions during the development of the visual system. Visual functions processed at higher anatomical levels within the system have a later critical period than functions processed at lower levels. This general principle suggests that treatments for amblyopia should be followed in a logical sequence, with treatment for each visual function to be started before its critical period is over. However, critical periods for some visual functions, such as stereopsis, are not yet fully determined, and the optimal treatment is, therefore, unknown. This article summarizes the current extent of our knowledge and points to the gaps that need to be filled.

Adolescent↗

PubMed2001

Visual determinants of reduced performance on the Stroop color-word test in normal aging individuals.

It is unknown to what extent the performance on the Stroop color-word test is affected by reduced visual function in older individuals. We tested the impact of common deficiencies in visual function (reduced distant and close acuity, reduced contrast sensitivity, and color weakness) on Stroop performance among 821 normal individuals aged 53 and older. After adjustment for age, sex, and educational level, low contrast sensitivity was associated with more time needed on card I (word naming), red/green color weakness with slower card 2 performance (color naming), and reduced distant acuity with slower performance on card 3 (interference). Half of the age-related variance in speed performance was shared with visual function. The actual impact of reduced visual function may be underestimated in this study when some of this age-related variance in Stroop performance is mediated by visual function decrements. It is suggested that reduced visual function has differential effects on Stroop performance which need to be accounted for when the Stroop test is used both in research and in clinical settings. Stroop performance measured from older individuals with unknown visual status should be interpreted with caution.

Aged↗

PubMed2001

Neuropsychological dysfunction, mood disturbance, and emotional status of munitions workers.

The objective of this study was to compare the neuropsychological function, emotional status, visual function, and illness prevalence of 265 former munitions plant workers (M age = 56.7 years, M years of education = 12.07; 201 African American, 64 White) exposed to organic solvents for an average of 17.03 years with that of a group of 77 unexposed controls (M age = 51.3 years, M years of education = 13.07; 30 African American, 47 White). Neuropsychological tests were selected from the World Health Organization Neurobehavioral Core Test Battery, Wechsler Adult Intelligence Scale-III (WAIS-III), and Wechsler Memory Scale-III (WMS-III) and also included the Brief Symptom Inventory, Profile of Mood States, Beck Anxiety Inventory, and Beck Depression Inventory. Vision tests included the Lanthony d-15 color vision, the Vistech Contrast Sensitivity, and the Snellen. The exposed group showed greater deficits than the controls in verbal learning (WMS-III Logical Memory I Learning Slope and Word Lists I Recall), visuomotor tracking speed (Cancellation H, WAIS-III Digit Symbol-Coding) and psychomotor function (Dynamometer and Grooved Pegboard), and dysfunction in emotional status, illness prevalence, and visual function. African American workers reported higher levels of exposure than Whites. Exposure relations demonstrated increased neuropsychological dysfunction with increased exposure.

Adult↗

PubMed2005

[Effect of refraction procedures (LASIK) on various ocular functions (initial results)].

PURPOSE: to determine effect of laser in situ keratomileusis (LASIK) on visual functions: visual acuity (VA) and contrast sensitivity (CS). PATIENTS AND METHODS: Prospective study includes results of VA and CS preoperatively and 1, 3 and 6 months postoperatively in patients with middle and high myopia. 36 eyes of 18 patients (3 men and 15 women) were divided according to spherical equivalent into 2 groups: group A (> -5.0 D, 18 eyes) and group B (< -5.0 D, 18 eyes). Mean patient's age was 27 years (range 19-46 years). Visual acuity was measured on logMAR charts, contrast sensitivity at 3, 6, 12 and 18 c/deg was tested using CSV 1000 Contrast sensitivity unit. In both groups, results of preoperative best corrected visual acuity (BCVA) were compared to uncorrected visual acuity (UCVA) after surgery. RESULTS: Visual acuity preoperatively was significantly decreased in comparison to controls in both groups, considerable decrease can be detected at 1 month postoperatively and it returns to preoperative values during 6 months after surgery. Postoperatively, a significant decrease of CS can be detected, above all at intermediate spatial frequencies. During first 6 months, values of CS slowly increase in both groups. However, only in group B (< -5D) the preoperative values have been reached. CONCLUSIONS: Our study suggests that both used methods are very sensitive for evaluation of visual functions after refractive surgery. Changes of contrast sensitivity reveal even slightly changed optic factors of cornea that can cause subjective complaints of patients.

Adult↗

PubMed2000

Visually impaired Swedish children. The 1980 cohort study--a 19-year ophthalmological follow-up.

PURPOSE: To assess the ophthalmological outcome in a cohort of visually impaired children in a geographically defined area. METHODS: A 19-year follow-up of medical records, interview and, if needed, re-examination of the initial 128 patients, born 1962-1976. RESULTS AND CONCLUSION: Follow-up was possible in 123 patients (96%); 76 (59%) were still visually impaired, 17 (13%) were deceased, while 30 (23%) had acquired a visual function > or = 0.3. The chances of gaining a visual function outside the WHO limits for visual impairment was significantly higher for patients without additional impairments (p=0.0023). The initial ophthalmologic diagnosis remained unchanged in 88%. The diagnoses with improved visual development included albinism and congenital nystagmus, while retinal diseases showed poorer results. An increase in visual function could be seen even in the initially older age-groups, indicating a maturation of visual function beyond what is usually considered the limit of plasticity of the visual system.

Adolescent↗

PubMed2000

Visualizing the function computed by a feedforward neural network.

A method for visualizing the function computed by a feedforward neural network is presented. It is most suitable for models with continuous inputs and a small number of outputs, where the output function is reasonably smooth, as in regression and probabilistic classification tasks. The visualization makes readily apparent the effects of each input and the way in which the functions deviate from a linear function. The visualization can also assist in identifying interactions in the fitted model. The method uses only the input-output relationship and thus can be applied to any predictive statistical model, including bagged and committee models, which are otherwise difficult to interpret. The visualization method is demonstrated on a neural network model of how the risk of lung cancer is affected by smoking and drinking.

Alcohol Drinking↗

PubMed1995

Visual acuities and scotomas after 3 weeks' levodopa administration in adult amblyopia.

BACKGROUND: Previous studies have shown that both a single dose of levodopa and a 1-week administration of levodopa improve visual functions in adult amblyopic patients. In the present study, we investigated the effect of increased dosage and duration of levodopa on amblyopes' visual functions. METHODS: Visual acuity and visual fields were examined before and after 3 weeks of daily administration of levodopa/carbidopa as well as 1 month and 2 months after completion of drug therapy in a double masked-design. RESULTS: A significant increase in visual acuities and a decrease in fixation point scotomas were found. Changes were of comparable dimension to those found after 1 week of levodopa administration. Improvement of visual functions persisted 2 months after the levodopa/carbidopa administration was completed. CONCLUSION: The present study confirms previous findings of improvement in visual function in amblyopia after levodopa/carbidopa administration. However, increasing the dosage and the duration of levodopa did not enhance the effect in adults.

Administration, Oral↗

PubMed1999

Characteristics of AMD patients with low vision receiving visual rehabilitation.

The purpose of this retrospective study done on 255 AMD patients evaluated at a low vision rehabilitation service was: 1) to describe the visual function characteristics (VFCs) of AMD patients presenting to visual rehabilitation, 2) to document changes in these VFCs between initial and follow-up rehabilitation visits, and 3) to investigate the relationship of the VFCs found at rehabilitation intake to the length of time between initial diagnosis and initial rehabilitation visit. Standard clinical testing (visual acuity and contrast sensitivity) as well as Scanning Laser Ophthalmoscope (SLO) visual function testing were performed to determine visual function including: 1) macular perimetry for scotoma boundary mapping and 2) PRL (preferred retinal locus) location and abilities in fixation, saccadic, and pursuit eye movements. The difference between the first and second visit VFCs were compared to the length of time between visits for 44 of the 255 patients returning for a second visit 0.5 to 4.5 years later. Finally, the initial date of AMD diagnosis was found for 51 of the 255 patients to analyze VFCs as a function of the time duration between diagnosis and the intake to the rehabilitation. Most VFCs had a wide range of results at initial intake to rehabilitation, while all patients had significant visual impairment by 24 months after initial diagnosis. The majority of low vision patients with AMD have bilateral central scotomas with the corresponding visual function and ADL problems that can often be overcome with visual rehabilitation.

Aged↗

PubMed2006

Assessment of function related to vision (AFREV).

OBJECTIVES: To evaluate the relationship of a performance-based measure of visual functioning to clinical and subjective measures in glaucoma patients. DESIGN: Cross-sectional survey of glaucoma patients. PARTICIPANTS: Forty-three patients with primary open-angle glaucoma. METHODS: Patients were evaluated using a novel performance-based measure, the Assessment of Function Related to Vision (AFREV), standard clinical tests of visual function, and the National Eye Institute's Visual Functioning Questionnaire (NEI-VFQ-25), a self-reported quality of life measure. Correlations of the AFREV scores with visual field scores, monocular and binocular visual acuity, contrast sensitivity scores, and NEI-VFQ scores were calculated. Rasch analysis was used to estimate the visual ability required by each task of AFREV for a particular response (item measures) and to estimate the visual ability of each patient (person measures). MAIN OUTCOME MEASURES: AFREV and NEI-VFQ total scores. RESULTS: The AFREV total scores were highly correlated with contrast sensitivity (r = 0.772), binocular visual acuity (r = -0.768), better-eye visual acuity (r = -0.737), worse-eye visual acuity (r = -0.675), and Estermann visual field efficiency scores (r = 0.606) as well as with NEI-VFQ scores (r = 0.70). The resulting index, constructed from 5 items of the AFREV, is unidimensional, thereby satisfying the primary assumption of the Rasch model. The Rasch person-item map demonstrates that the "putting stick into holes" and "reading small print" tests require the most visual ability. CONCLUSIONS: The AFREV performance-based measure, a new test of a spectrum of activities, correlates well with some standard measures of visual function and certain aspects of self-report assessments. AFREV appears to be a valid measure of performance ability that may provide information not obtainable from standard measures of visual function or subjective surveys.

Activities of Daily Living↗

PubMed2006

Targeted disruption of the murine retinal dehydrogenase gene Rdh12 does not limit visual cycle function.

RDH12 codes for a member of the family of short-chain alcohol dehydrogenases/reductases proposed to function in the visual cycle that supplies the chromophore 11-cis retinal to photoreceptor cells. Mutations in RDH12 cause severe and progressive childhood onset autosomal-recessive retinal dystrophy, including Leber congenital amaurosis. We generated Rdh12 knockout mice, which exhibited grossly normal retinal histology at 10 months of age. Levels of all-trans and 11-cis retinoids in dark- and light-adapted animals and scotopic and photopic electroretinogram (ERG) responses were similar to those for the wild type, as was recovery of the ERG response following bleaching, for animals matched for an Rpe65 polymorphism (p.L450M). Lipid peroxidation products and other measures of oxidative stress did not appear to be elevated in Rdh12(-/-) animals. RDH12 was localized to photoreceptor inner segments and the outer nuclear layer in both mouse and human retinas by immunohistochemistry. The present findings, together with those of earlier studies showing only minor functional deficits in mice deficient for Rdh5, Rdh8, or Rdh11, suggest that the activity of any one isoform is not rate limiting in the visual response.

Alcohol Oxidoreductases↗

PubMed1998

Automatic static threshold perimetry is useful for estimating the effects of laser photocoagulation on diabetic maculopathy.

Focal photocoagulation was performed on 18 eyes in 18 diabetes patients; a visual acuity test, fluorescein angiography and automated static threshold perimetry by Octopus automated static perimetry (program 31) were conducted before and 1, 3 and 6 months after krypton laser photocoagulation. Central field sensitivity and total loss were measured by automated static threshold perimetry. Group A (13 eyes) had a total loss of less than 150 dB. In these subjects, mild fluorescein leakage was detected within the area of the vascular arcade. In group B (5 eyes) with a total loss of greater than 150 dB, diffuse fluorescein leakage was also detected outside the vascular arcade. The central field sensitivity was reduced in 2 eyes of group B. The total loss worsened in 8 eyes of group A (61.5%) and 5 eyes of group B (100%). Inspection of photographs gave the impression that the degree of fluorescein leakage and the area of the avascular zone on fluorescein angiography accorded with total loss, thus suggesting that total loss reflects visual functions better than visual acuity or central field sensitivity. Therefore, automated static threshold perimetry appears to be a useful method for estimating visual functions after photocoagulation in diabetic maculopathy patients.

Adult↗

PubMedDate not supplied

Measurement of low vision in advanced cicatricial retinopathy of prematurity.

This study evaluates functional vision in visually impaired children with stage IV to V cicatricial retinopathy of prematurity (CROP) by comparing results derived from the Teller acuity cards and a battery of behavioral tasks, the visual function battery (VFB). Vision was evaluated in 26 eyes of 15 children ages 6 months to 14 years, who underwent retinal reattachment procedures for active stage IV and stage V retinopathy of prematurity. Results showed that 10 of 26 eyes (38%) had a recordable grating acuity to Teller acuity card assessment. Twenty-five of 26 eyes (96%) showed a response to the VFB. Sixteen of 26 eyes (62%) showed recordable scores with the VFB but no corresponding scores with the Teller acuity cards. The VFB may be more reliable than the Teller acuity cards in measuring visual function in the very low acuity range.

Adolescent↗

PubMed2006

Visual development in infants with prenatal post-haemorrhagic ventricular dilatation.

OBJECTIVE: The aim of this study was to assess visual function in 13 infants with evidence of prenatal post haemorrhagic ventricular dilatation. DESIGN: Infants were assessed at 5, 12 and 24 months using a battery of tests specifically designed to assess various aspects of visual function in infancy. Visual findings were correlated with several variables, including extent of the lesion and presence of epilepsy. RESULTS AND CONCLUSIONS: Abnormalities of visual function were frequent (over 60%) in our cohort at age 2 years, ranging from isolated abnormal ocular movements to severe abnormalities of all the aspects of visual function assessed. The most severe and persistent abnormalities of visual function were found in infants with grade IV intraventricular haemorrhage and shunted hydrocephalus who also had epilepsy in the first year.

Cerebral Hemorrhage↗

PubMed2000

[Measurement and evaluation of visual index in VDT operators under Multi-user system].

OBJECTIVE: To evaluate the visual function of the visual display terminal (VDT) operators under the Multi-user system. METHOD: Subjective symptoms of the VDT operators under the Multi-user system were measured before and after work in the field study. Visual indices were measured at 8:15, 9:15, 10:15, 11:15, or 12:15 a.m. RESULT: No discomfort symptom was observed during the working time, and Longitudino-Kinetic visual acuity, and Critical flicker frequency didn't decrease. Refraction showed no significant decrease as compared with that at 8:15 except that of right eye measured at 12:15. CONCLUSION: The Visual function of the VDT operators remained good in the Multi-user's system.

Adolescent↗

PubMed1993

Long-term effectiveness of optic nerve sheath decompression for pseudotumor cerebri.

OBJECTIVE: To determine the long-term success of optic nerve sheath decompression in preserving visual function in patients with pseudotumor cerebri (PTC). DESIGN: To define stability of visual fields, we reviewed 32 series of postoperative visual fields in patients who were undergoing optic nerve sheath decompression for PTC who had stable visual acuity and four or more fields during 6 to 60 months of follow-up. The SD of these series was 0.80 dB (+/- 0.39 dB) of mean deviation. Fluctuations within 2 SDs of the 1-month postoperative field were +/- -1.60 dB. We therefore defined stability as a mean deviation within 2 dB of the preoperative visual field; improvement, greater than 2-dB mean deviation, and worsening, less than 2-dB mean deviation. We then extended our review to include all patients (54 patients, 75 eyes) who underwent optic nerve sheath decompression for PTC, who were followed up with serial automated perimetry (Humphrey 30-2). RESULTS: Fifty-one eyes (68%) showed improvement (36%) or stabilization (32%) of visual function. Twenty-four eyes (32%) experienced deterioration of visual function after an initially successful optic nerve sheath decompression. The probability of failure from 3 to 5 years was .35 by life-table analysis. CONCLUSION: Optic nerve sheath decompression effectively stabilizes or improves visual function in the majority of patients with PTC and visual loss. However, it may fail at any time after surgery. Patients with PTC need to be followed up routinely with automated perimetry to detect deterioration of visual function.

Adolescent↗

PubMed2001

Bilateral endogenous Candida endophthalmitis after induced abortion.

AIM: Analysis of the development and treatment of bilateral Candida endophthalmitis after induced abortion in a healthy 31-year-old patient. METHOD: A diagnosis of bilateral Candida endophthalmitis was established on the basis of positive vaginal culture, serological finding, and culture for Candida hyphae from the vitreous aspirate. The treatment of the disease consisted of prolonged systemic therapy with amphotericin B and fluconazole and pars plana vitrectomy with intravitreal amphotericin B injection. RESULTS: After the combined systemic therapy with antibiotics, fungistatics, and corticosteroids proved to be insufficient, pars plana vitrectomy with intravitreal instillation of amphotericin B was performed, which led to the improvement of visual function. After surgery, visual function was maintained with prolonged systemic therapy with fluconazole and methylprednisolone. CONCLUSION: Complicated induced abortion may cause bilateral Candida endophthalmitis in a young healthy woman. Elimination of the cause of fungemia and adequate systemic treatment did not cure bilateral endophthalmitis. Pars plana vitrectomy with intravitreal instillation of 5-microg amphotericin B proved as a method of choice in treating this severe ophthalmic disease.

Abortion, Induced↗