SEARCH · PubMed Health

Results for “Visual function”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources

PubMed2002

[Visual function study in work with computer].

This investigation searched for the relationship between amount of nearwork, asthenopic symptoms and visual function, in a group of office workers engaged in telemarketing. Phoria, monocular accommodative facility with +/- 2 lens flippers and near point of convergence were measured in 100 office workers (mean age 21 +/- 2.6 years) whose uncorrected visual acuity was 20/30 or better. Daily hours of reading hard-copy and of computer use, and the level of asthenopic symptoms, were measured using a questionnaire. In this sample, telemarketers were involved 5.84 +/- 2.02 daily hours in computer use, and 2.87 +/- 2.13 daily hours in reading. The following asthenopic symptoms were present twice or more times in a week: headaches 16%, pain in the eyes 17%, red eyes 18%, blurred vision 10%, double vision 3%, burning eyes 19% and watery eyes 19%. An association was found between the amount of hours using computers and red eyes (chi 2 = 4.4, p = 0.0359) or blurred vision (chi 2 = 8.35, p = 0.0038). And also between deficit of convergence and headaches (chi 2 = 4.3313, p = 0.0374) or red eyes (chi 2 = 3.6416, p = 0.0564). No other associations could be found between the accommodative facility test results, the near point phoria, and the amount of nearwork or the asthenopic symptoms. In conclusion, computer use in telemarketing is associated with few asthenopic symptoms. Near point of convergence should be routinely measured, as it is associated with some asthenopic symptoms.

Accommodation, Ocular↗

PubMed1994

Rhinogenous optic neuritis with drastic diurnal variation of visual function.

We report a case of rhinogenous optic neuritis in a 50-year-old man demonstrating drastic diurnal variation in visual function. His left vision was 20/15 in the morning, which gradually decreased to counting fingers at night. Pupillary reaction and visual field showed the same fluctuation as vision. Complete remission of visual symptoms was achieved after endonasal ethmoid sinusotomy.

Circadian Rhythm↗

PubMed1985

Joint application of hyperacuity perimetry and gap tests to assess visual function behind cataracts: initial trials.

We have developed two related clinical tests that offer potential in better assessing visual function behind an ocular opacity. The tests are resistant to the effects of opacities because they utilize a localization task (vernier acuity) rather than a resolution task. In this paper we report the initial trials in which we apply the two tests together. Results from six case studies (some with actual opacities and some with simulated opacities) illustrate both the conduct of the tests and their potential capabilities in detecting even very modest retinal dysfunction in the presence of opacities. These techniques offer considerable potential in the separation of a given acuity loss observed in the presence of cataract into a portion due to the opacity and a portion due to retinal dysfunction.

Aged↗

PubMed2006

Evaluation of the National Eye Institute visual function questionnaire in Graves' ophthalmopathy.

PURPOSE: To determine the potential suitability of the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) for measuring health-related quality of life (HRQL) in patients with Graves' ophthalmopathy. DESIGN: Cross-sectional study. PARTICIPANTS: Thirty adult patients with mild to severe Graves' ophthalmopathy. METHODS: Participants self-administered the NEI VFQ-25 and completed a semistructured interview to provide feedback about the questionnaire. The percentage of responses at the maximum and minimum value was calculated to assess ceiling and floor effects, respectively, for the 12 subscales of the NEI VFQ-25. The NEI VFQ-25 scores were compared for Graves' ophthalmopathy patients who reported symptomatic diplopia and those who did not report diplopia using univariate and multivariate linear regression models. MAIN OUTCOME MEASURES: The NEI VFQ-25 subscale and composite scores. RESULTS: Health-related quality of life in those with Graves' ophthalmopathy was moderately impaired, with median composite score of 69. The greatest impairment was measured in the Mental Health (median, 50) and the Role Difficulties (median, 50) subscales. Significant ceiling effects were seen in 7 of the 12 subscales. More than two thirds of Graves' ophthalmopathy patients perceived that the NEI VFQ-25 lacked items relevant to their disease. The NEI VFQ-25 scores were lower for those with diplopia symptoms (composite score, 61) compared with those without diplopia (composite score, 90). Comparing these 2 groups, the largest differences were measured in the Driving and Peripheral Vision subscales. CONCLUSIONS: The NEI VFQ-25 includes many items that are applicable to Graves' ophthalmopathy patients. However, it shows significant ceiling effects in more than half of the subscales and it lacks items on issues that are important to Graves' ophthalmopathy patients, such as altered appearance and ocular discomfort. Efforts to develop an HRQL instrument that adds Graves' ophthalmopathy-specific items to relevant aspects of the NEI VFQ-25 are warranted.

Adult↗

PubMed1998

Visual function and patient satisfaction after macular hole surgery.

PURPOSE: Over recent years success in macular hole surgery has increased in terms of anatomical closure. However, debate still continues on the benefit to the patient in terms of visual outcome. We designed a prospective study to investigate the outcome of full thickness macular hole (FTMH) surgery in terms of anatomical closure, visual outcome, incidence of complications and patient satisfaction. METHODS: Thirty eyes of 30 consecutive patients with FTMH were prospectively studied (stage 2 = 2; stage 3 = 23; stage 4 = 5). All cases had surgery involving vitrectomy, injection of an autologous platelet aggregate over the hole and gas tamponade. At 3 months post-operatively all cases were assessed for closure of the FTMH, Snellen acuity and the incidence of complications. At this stage all patients completed a patient satisfaction questionnaire. RESULTS: Anatomical closure of the hole was achieved in 83% of cases (25/30). Visual improvement of 2 Snellen lines or more occurred in 50% of cases (15/30). A vision of 6/12 or better was achieved in 27% of cases (8/30). A post-operative lens opacity was present in 46% (13/28) of phakic patients and a temporal, peripheral wedge-shaped field defect occurred in 17% (5/30) of cases. In this study, 53%, 70%, 57% and 67% of patients gave a positive response to specific questions about satisfaction with near, intermediate and distance vision and overall visual function respectively. CONCLUSIONS: Although the anatomical success of FTMH surgery is high the functional outcome in terms of Snellen acuity is less rewarding. Analysis of patient satisfaction suggests that the arbitrary visual outcome measures presently used may underestimate the functional benefit to the patient. Improved objective measures of visual outcome are required to assess the benefit of surgery in these cases.

Aged↗

PubMed1992

Assessment of central visual function after successful retinal detachment surgery by pattern visual evoked cortical potentials.

The pattern of visual recovery after successful surgery by pattern visual evoked cortical potentials (VECP), visual acuity, colour vision, and critical fusion frequency was investigated in 14 eyes with retinal detachment involving the macula. The temporal tuning characteristics in the evoked potentials were measured as based on the P100 amplitude and the frequency necessary for evoking 0 mu V amplitude, which was defined as an objective critical fusion frequency by extrapolating the curve. Significant improvement in visual acuity and colour vision was observed within 2 months postoperatively. A significantly increased P100 peak latency became shorter as the postoperative days increased. In general, a good correlation was noted between the P100 peak latency and subjectively measured visual acuity, colour vision, and critical fusion frequency. The objective critical fusion frequency measured by VECP recovered gradually during the 6 months after surgery. Functional recovery was not related to the length of time the macula was detached before surgery.

Adolescent↗

PubMed2001

[The ability of frequency doubling technology to detect abnormality of visual function in early glaucoma].

PURPOSE: To evaluate the ability of the Frequency Doubling Technology(FDT) threshold test in detecting abnormality of visual function in early glaucoma patients. SUBJECTS AND METHOD: The C-20 full threshold test of FDT was performed on 34 normal-tension glaucoma(NTG) patients and 39 primary open-angle glaucoma(POAG) patients with visual field defects limited to the upper or lower hemi-field as detected by Humphrey Field Analyzer(HFA) and on 79 normal control subjects. Optic disk findings and FDT results corresponding to the intact hemi-field were evaluated. FDT abnormalities in normal subjects were calculated as false positive rates in FDT. RESULT: The sensitivity and specificity of FDT, calculated based on optic disk findings, were 75.0% and 61.1% in POAG, and 61.1% and 66.7% in NTG, respectively, while the false positive rate in normal subjects was 11.4%. CONCLUSION: FDT can detect glaucomatous functional abnormality earlier than HFA.

Adult↗

PubMed1994

Remarkable recovery of visual function in a patient with Leber's optic neuropathy and multiple mutations of mitochondrial DNA.

Almost complete spontaneous recovery in visual function was observed in a male patient with Leber's hereditary optic neuropathy (LHON), in spite of the presence of several LHON-associated "major" and "minor" mutations of mitochondrial DNA. Our findings confirm that visual loss in LHON may be reversible, and challenge the hypothesis of a "synergistic" effect of multiple mtDNA mutations in the phenotypic expression of the disease.

Adolescent↗

PubMed2003

Assessment of visual functions following prenatal exposure to organic solvents.

Prenatal exposure to organic solvents has been previously associated with increased risk of color vision deficits and reduced visual acuity in young children. These findings prompted us to evaluate visual functioning in solvent-exposed infants using more sensitive non-invasive visual evoked potential (VEP) techniques. VEP techniques are described in the context of an ongoing prospective longitudinal cohort study of infants exposed to organic solvents in utero. VEPs are recorded via three active electrodes fitted over the occipital cortex while infants view changing visual stimuli. The sweep VEP is used to assess contrast detection and visual acuity by presenting sinusoidal gratings that "sweep" across a range of contrasts and spatial frequencies. Transient VEPs are used to assess responses to equiluminant chromatic- and luminance-modulated sinusoidal gratings presented in pattern onset-offset format. A single case study is presented showing abnormal chromatic responses and reduced contrast sensitivity in a 2.5-year-old boy following prenatal exposure to perchloroethylene (PCE). These VEP techniques therefore appear promising for the clinical assessment of visual toxicity in pediatric populations.

Child, Preschool↗

PubMed1996

Effects on visual functions during tasks of object handling in virtual environment with a head mounted display.

This study examined the effects on visual functions of a prolonged handling task within the helmet-mounted display environment. Both version eye movement and accommodative response became gradually slower during the 40-min task. Although delayed presentation of display after head movement noticeably worsened both visual responses, presentation delay after hand movement did not significantly change the sluggishness of responses. Therefore it is suggested that decreasing time delay after head movement is a more important factor in order to improve human performance of handling tasks within the HMD environment.

Accommodation, Ocular↗

PubMed1994

[Changes in visual function caused by work at a data display terminal].

Working at video display terminals (VDTs) is particularly demanding in terms of orthopaedic and visual functions. This study was initiated to examine whether, and if so how, VDT work can influence the visual system. It was designed as a 5-year-prospective study based on the matched-pairs technique. The subjects were examined at the beginning and after 5 years of VDT work. The study group consisted of 102 people working at VDTs, and these were paired with 102 other office workers who did not use VDTs. The legally prescribed screening examinations of visual acuity (distance and near vision, phorias, stereopsis, and colour vision) were carried out. We also checked the anterior segments by examination with the slit-lamp and the fundus by ophthalmoscopy. Break-up time, Schirmer-I test, perimetry and tonometry were included in our range of examinations. We found a significant difference in asthenopia and daily hours of VDT work between VDT workers working less than 6 h daily and those working more than 6 h daily. In the study group pre-existing exophoria seemed to increase, but no statistical significance was found on testing. Nor was there any significant difference between the study group and the control group in the parameters examined in the course of the screening examination. In our investigation of monocular VDT workers (n = 3) we could not find any visual problems.

Adult↗

PubMed1976

Developing visual function in the red jungle fowl embryo.

The onset of visual system function in the wild red jungle fowl embryo was measured by the pupillary reflex technique and compared with its domesticated descendant, the domestic chick. The first neurally mediated pupillary reflex in the jungle fowl embryos was found at Day 15 of incubation after 77% of incubation was completed. This point did not differ significantly from the onset of this reflex in the domestic chick embryo (after approximately 83% of incubation). Thus, it was concluded that the relatively late onset of overt visual system function in the chick, as compared with several other precocial avian species, was not a result of its history of intense domestication but rather was most likely a normal characteristic of this and other closely related species.

Age Factors↗

PubMed2003

Retinal image contrast and functional visual performance with aspheric, silicone, and acrylic intraocular lenses. Prospective evaluation.

PURPOSE: To compare the effects of an aspheric intraocular lens (IOL) (Tecnis Z-9000, Pharmacia Corp.) with those of conventional silicone (AA4207VF, Staar Surgical) and acrylic (AcrySof SA60AT, Alcon Surgical) lenses on retinal imaging and functional visual performance. SETTING: Eye Laser Center, Tucson, Arizona, USA. METHODS: In this prospective study, 221 eyes of 156 patients were randomly assigned to receive 1 of 3 IOLs. Visual acuity was measured preoperatively and 1 day, 1 and 3 weeks, and 1, 3, and 6 months postoperatively. Fundus photography and photopic and mesopic functional acuity contrast testing were performed preoperatively and 3 months postoperatively. RESULTS: The differences in the preoperative and postoperative spherical and astigmatic refractive errors and best corrected visual acuity among groups were not statistically significant. The postoperative uncorrected visual acuity was best in the aspheric group in the first month. Functional acuity contrast testing showed the aspheric IOL group had a 38% to 47% increase in photopic vision, 38% in photopic with glare, 43% to 100% in mesopic, and 9% to 100% in mesopic with glare. There was no increase in photopic vision in the acrylic group but increases of 38% in photopic with glare, 25% to 50% in mesopic, and 36% to 50% in mesopic with glare. The spherical silicone IOL group had no increase in contrast testing from preoperatively. Digital analysis of retinal imaging showed increased threshold luminance levels in the aspheric group (range 116 to 208 cd/m2) and a 4-fold increase in image contrast. CONCLUSIONS: All 3 IOLs led to improved visual acuity after cataract surgery. The aspheric IOL provided a significant improvement in retinal image contrast and visual performance measured by visual acuity and functional acuity contrast testing. This improvement was greatest in night vision and night vision with glare compared to the performance of conventional spherical silicone and acrylic IOLs.

Acrylates↗

PubMed2002

[Evaluation of the visual function in employees working with computers].

PURPOSE: To evaluate the effects of long-term work with computer monitor on the accommodation, convergence, stereopsis, near and distant visual acuity. MATERIAL AND METHODS: The studies of the accommodation, convergence, stereopsis, near and distant visual acuity have been performed in 50 employees working with the computer 6.5 hours daily, 5-6 days weekly and 5 to 12 years. The same studies have been performed in 50 white-collar workers, who had no contact with the computer in their work. RESULTS: No changes in the accommodation, convergence, stereopsis, near and distant visual acuity have been found in the employees in both studies groups. CONCLUSION: Long-term work with the computer monitor does not cause changes in the visual function of the employees. Reported changes are probably cause by the visual fatigue associated with the near work, and not by the direct influence of the computer monitor.

Accommodation, Ocular↗

PubMed2003

The Italian version of the 25-item National Eye Institute Visual Function Questionnaire: translation, validity, and reliability.

OBJECTIVE: To test the Italian adaptation of the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ 25) and to investigate its validity and reliability. METHODS: This prospective observational study enrolled nonhospitalized patients with 1 of 5 chronic eye diseases, and a reference sample of subjects without eye diseases. Eligible participants had to be cognitively able to respond to a health status interview and be affected by 1 of the following eye conditions: senile cataract, age-related macular degeneration, glaucoma, diabetic retinopathy, and cytomegalovirus retinitis or low vision. A control group was composed of subjects with no evidence of underlying eye diseases. The Italian self-administered versions of Medical Outcomes Study Short Form and of the NEI-VFQ 25 were administered to all participants. Reliability and validity of the Italian translation of the NEI-VFQ 25 were tested using statistical methods. RESULTS: Statistical analysis points out that the Italian version of the NEI-VFQ 25 has good validity, discriminatory power, internal consistency, and reliability. CONCLUSIONS: This Italian version of the NEI-VFQ 25 shows psychometric properties comparable to those of the American version, and thus can be used in clinical research as a specific measure of quality of life in patients with chronic eye diseases.

Case-Control Studies↗

PubMed1997

Validation of French-language versions of the Visual Functioning Index (VF-14) and the Cataract Symptom Score.

OBJECTIVE: To produce and validate French-language versions of the Visual Functioning Index (VF-14), the Cataract Symptom Score (CSS) and two global measures of trouble and satisfaction with vision. DESIGN: Survey by means of telephone interviews conducted 2 weeks apart. SETTING: Ophthalmology clinic of a teaching hospital in Montreal. SUBJECTS: Subjects were recruited among patients with ocular media opacities, such as cataracts and corneal opacities. Of the 71 subjects recruited, 66 (41 French-speaking and 25 French- and English-speaking) completed the study. OUTCOME MEASURES: Visual acuity, scores on vision-related questionnaires and on the 36-Item Short-Form Health Survey (SF-36), a measure of perceived health status. RESULTS: The integral consistency of the French-language versions of the VF-14 and the CSS was high, with Cronbach alpha values of 0.96 and 0.82 respectively. The fidelity with regard to the English-language version, the test-retest reproducibility and the interrater agreement were high (intraclass correlation coefficients > or = 0.80). The correlation between the visual acuity of the better eye and the mean score on all four vision-related measures was statistically significant (p < or = 0.05). The VF-14 scores were also correlated with the score on five of the eight SF-36 subscales (p < or = 0.05). CONCLUSIONS: Our results show that French-language versions of the VF-14, CSS and global measures of trouble and satisfaction with vision are reliable and valid.

Adult↗

PubMed1998

Oscillopsia: visual function during motion in the absence of vestibulo-ocular reflex.

OBJECTIVES: To investigate (1) the effects of loss of vestibular function on spatiotemporal vision and (2) the mechanisms which enable labyrinthine defective (LD) patients to adapt to oscillopsia. METHODS: Visual function and eye movements were assessed in seven normal subjects and four LD patients with oscillopsia due to absent vestibulo-ocular reflex. Temporal vision was assessed by measurement of threshold sensitivity for detection of a target which moved across a flickering, spatially uniform background field. Spatial vision was investigated by measurements of threshold sensitivity for the detection of a target moving across a spatially modulated background in the form of square wave gratings. Velocity discrimination was assessed with drifting gratings. All measurements were made under static conditions and during oscillatory movement of either the visual stimulus or the subject (1 Hz, peak velocity 50 degrees/s). RESULTS: Temporal responses--Normal subjects and LD patients exhibited similar responses while static and under body oscillation. Spatial responses--The two groups achieved similar results under static conditions but body oscillation reduced threshold sensitivities and shifted the spatial response function towards lower spatial frequencies in the LD patients only. Similar changes in the spatial responses were seen during oscillation of the visual stimulus but these occurred in both normal subjects and LD patients. Velocity discrimination--Two LD patients achieved normal velocity discrimination but the other two showed abnormal responses to visual stimulus movement; one displayed a loss of velocity discrimination during whole body oscillation, and the other mismatched the velocity of two moving grating stimuli. CONCLUSIONS: The changes in the spatial responses are attributed to the presence of retinal slip during visual stimulus motion in all subjects or body oscillation in the LD patients. It is concluded that any visual adaptation to oscillopsia achieved by the LD patients does not influence the measured spatial response functions, which arise at an early stage of visual processing. The abnormal velocity discrimination may relate to the progressive improvement in oscillopsia reported by LD patients.

Adult↗

PubMed2004

A prospective study of visual function and quality of life following PDT in patients with wet age related macular degeneration.

AIMS: (1) A prospective study to assess visual function measures and quality of life (QoL) in patients with wet age related macular degeneration (AMD) treated with photodynamic therapy (PDT). (2) To assess if PDT prevents severe visual loss (loss of six or more lines of distance visual acuity) in the treated eye. METHODS: 48 of 51 recruited patients with predominantly classic subfoveal choroidal neovascularisation (CNV) secondary AMD who were treated with PDT were followed up for 1 year. Assessment included distance and near visual acuity, contrast sensitivity, vision related quality of life and fluorescein angiography. Photodynamic therapy using Visudyne was carried out according to standard protocol. Patients were followed up every 3 months and treatment repeated if there was significant leakage from CNV. RESULTS: At the 12 month follow up, 71% (n = 34) of the patients lost less than three lines of best corrected distance visual acuity. Although there were significant decreases in some of the QoL items tested, patients were significantly less anxious and more independent outdoors at the 12 month follow up. CONCLUSION: This study is in keeping with published literature with PDT preventing severe visual loss in two thirds of treated patients with predominantly classic CNV.

Activities of Daily Living↗