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At least 613 records · Page 34Linked to original sources

PubMed2004

Psychometric Validation of the National Eye Institute Visual Function Questionnaire - 25 (NEI VFQ-25) French version: in a population of patients treated for ocular hypertension and glaucoma.

OBJECTIVE: Physicians need reliable, valid and sensitive questionnaires to assess QOL related to glaucoma or ocular hypertension. This article presents the psychometric properties of the French version of the National Eye Institute Visual Function Questionnaire - 25 (NEI VFQ-25). METHODS: A mail survey was sent to 20000 households. The survey identified 581 residents with glaucoma or ocular hypertension. Of these a random sample (n = 204) took part in a telephone survey during which the NEI VFQ-25 was completed by eligible patients (those taking at least one topical treatment for glaucoma or ocular hypertension on the day of the interview). Multi-trait analysis was performed to assess the construct validity of the questionnaire. Internal consistency reliability was assessed using Cronbach's alpha and the average inter-item correlation. Known groups validity was assessed by comparing patients grouped by duration of glaucoma, adjusted for age and gender. RESULTS: One hundred and seventy-three patients participated in the survey. Analysis of convergent validity showed that all of the items in each scale correlated above 0.40 with their own scale except for the 'driving' scale. The success rate of the discriminant validity ranged from 57.1% to 100% except for the 'driving' scale, which was 7.1%. Cronbach's alpha coefficients were all above 0.70 except the 'driving' score. Participants with glaucoma for less than 20 years consistently had better 'global', 'near vision', 'distant vision', 'driving', 'social function' and 'peripheral vision' scores than those with disease of 20+ years duration, indicating better QOL in patients with a shorter disease duration. CONCLUSION: The NEI VFQ-25 is a validated instrument to measure vision-targeted QOL in French populations with glaucoma.

Activities of Daily Living↗

PubMed1987

Vision for coloured pictures at different acuities: the Sonksen picture guide to visual function.

The vision 70 normal-sighted children was tested for both Snellen letters and life-size colour pictures of everyday objects. All the children wore spectacles for the tests: 60 were fitted with lenses which would induce a refractive error, the remainder had glassless frames only. Compared with acuity measures based on the Snellen letters, the pictures needed to be brought much closer than might be expected before the children with induced minor visual errors could recognise them. This highlights the importance of detecting and correcting refractive errors in preschool children who learn from such material, and suggests that the pictures may be a useful tool for detecting children with such errors. 18 pictures, comprising the Sonksen Picture Guide to Visual Function, have now been selected for this purpose.

Child↗

PubMed2000

Effects of long-chain polyunsaturated fatty acid supplementation on fatty acid status and visual function in treated children with hyperphenylalaninemia.

BACKGROUND: Children with phenylalanine-hydroxylase deficiency (type-I hyperphenylalaninemia, HPA) follow a low-phenylalanine diet, severely restricted in animal foods and long-chain polyunsaturated fatty acids (LCPUFA). Consequently, they have a poor LCPUFA status, particularly for docosahexaenoic acid (DHA). DHA is relevant to visual and neural development. OBJECTIVE: To investigate the effects of a 12-month supplementation with LCPUFA in a double-blind, placebo-controlled trial in treated children with HPA. STUDY DESIGN: Twenty children with well-controlled HPA were randomly allocated to receive either a fat supplement (supplying 26% as fatty acids including DHA, 8%) or a placebo. The fatty acid composition of erythrocyte lipids and the visual evoked potentials were measured at baseline and after 12 months of supplementation. Reference data were obtained from healthy children of comparable age. RESULTS: At baseline children with HPA had a poorer DHA status and prolonged P100 wave latencies than the reference group. At the end of the trial the LCPUFA group showed a significant increase in DHA levels of erythrocyte lipids. In the LCPUFA group P100 wave latency decreased and was negatively associated with the DHA changes. CONCLUSIONS: A balanced dietary supplementation with LCPUFA in children with HPA is associated with an increase of the DHA pool and improved visual function.

Child↗

PubMed1995

Visual function deficits in children.

In the past year, new work on sensory testing in preverbal infants has expanded our knowledge in three areas: 1) visual acuity testing in infants in varying levels of illumination; 2) visual evoked cortical potential-evidence for binocular function in infantile esotropia; and 3) a new time-efficient method to evaluate color vision in newborns and infants. A newly reported sequel to loss of binocularity is the development of A and V pattern strabismus. In another study, loss of fusion, as with acute concomitant esotropia, was shown to be a sign of serious intracranial disease. Regarding motor visual function deficits, new treatments of infantile esotropia syndrome and nystagmus with botulinum toxin type A are presented. Regarding social issues, visual function deficit of abused children and infants born to drug-abusing mothers are presented as a timely reminder that child abuse is still an enormous social problem, and that the visual system is far from exempt from damage.

Animals↗

PubMedDate not supplied

Contrast sensitivity letter charts as a test of visual function in amblyopia.

Anisometropic and strabismic amblyopes were studied using the Regan Contrast Sensitivity Charts. At all levels of contrast, the amblyopic eyes of both the strabismic and anisometropic patients scored significantly lower than did their fellow normal eyes, which were used as controls. In comparing the differences between the normal and amblyopic eyes of both groups, we noted a normalization of the visual function of strabismic amblyopes at low contrast. This feature was not observed in the anisometropic amblyopes who consistently scored poorly when viewing either the high or low contrast chart.

Adolescent↗

PubMedDate not supplied

Effect of photorefractive keratectomy on visual functioning and quality of life.

The authors present the results of the psychosocial outcomes of 45 patients undergoing excimer laser photorefractive keratectomy (PRK). The patients were evaluated by means of self-report questionnaires preoperatively and 6 months after surgery to determine the effect of uncorrected vision change on the patients quality of life. The measurements include the following variables: clinical end points (spherical equivalent refraction); visual function (night driving, day driving, near vision, far vision, glare disability); functional status (physical, social, and role functioning, mental status); general well-being (health perceptions, personal well-being, overall quality of life); and satisfaction with surgery (expectations, satisfaction with medical staff, postoperative pain, satisfaction with treatment outcomes). Preliminary results indicate that changes of uncorrected vision after PRK are reflected by improvement in each of the quality-of-life functions.

Activities of Daily Living↗

PubMed1996

[Unilateral congenital cataract and visual function].

The authors report the case of a young patient presented with cytomegalovirus infection involving the nervous, respiratory and ocular systems. A congenital monocular cataract associated with a chorioretinal macular scar in the controlateral eye imposed surgical treatment of the cataract. No retinal damages were found in the cataractous eye after surgery. Three years later the visual function is supported by the phakic eye in spite of the relative precocity of surgery (4th month), and of the correct antiambliopic treatment. This case would suggest that the period in which a monocular cataract can be treated with good functional results, should be restricted within the first few weeks of life.

Age Factors↗

PubMed2007

Quantitative fluorescein angiographic analysis of choroidal neovascular membranes: validation and correlation with visual function.

PURPOSE: To compare computerized analysis with traditional grading methods in the analysis of fluorescein angiograms from patients with choroidal neovascularization (CNV) due to age-related macular degeneration (AMD) and to examine the clinical relevance of parameters generated by computerized analysis by testing their relationships with clinical measures of vision. METHODS: Custom quantitative fluorescein analysis (QFA) software was used to analyze 62 angiograms from patients with CNV for whom distance visual acuity (DVA) data were available. On applying QFA, we obtained three mathematical parameters for each lesion component: pixel area (PA), integrated intensity (II), and positive fluorescence (PF). Quotients (Q) were derived for the latter two parameters by correcting against background (b) or optic nerve (o) fluorescence (IIQ(b), IIQ degrees , PFQ(b), and PFQ degrees ). The new metrics were compared with traditional grading parameters of classic CNV and lesion area. The relationships of both sets of angiographic data with measures of vision were explored by regression analyses. RESULTS: Weighted kappa between QFA and traditional grading for lesion subtype assessment was high (kappa = 0.7). Regression analyses with PA, IIQ(b), IIQ degrees , PFQ(b), and PFQ degrees for each lesion descriptor (leakage, classic CNV, occult CNV, total lesion) as independent variables and DVA as the dependent variable showed that in every case PFQ(b) exhibited the most significant relationship with vision (adjusted r(2) = 0.26). Parameter estimates showed that for a change of 30 units on the PFQ(b) for classic CNV, a loss of 20 letters of DVA may be expected. No parameters from traditional grading methods showed statistically significant relationships with DVA. CONCLUSIONS: The markers of dynamic change in area and intensity of fluorescence exhibited stronger relationships with visual function than did area measurements alone.

Choroidal Neovascularization↗

PubMed1995

[Personal computer used in visual function screening].

BACKGROUND: The number of medical screenings is increasing. This fact is specially pronounced in the field of occupational health. Due to restricted financial resources and limitations in time there is a need for rationalisation in medical screenings. MATERIALS AND METHODS: Possible uses of personal computers (PC) enabling organisational and financial benefits in medical screenings are suggested. By means of a test for colour-blindness it is shown how unfavourable technical conditions may be by-passed. RESULTS AND DISCUSSION: Rationalisation in medical screenings can be achieved when using the PC as a multi-functional screening-device as well as an expert system, measuring apparatus and as a communication-device. Due to a lack of literature it is difficult to discuss possible effects of technical differences between PC-based screenings of visual functions and screenings where "traditional". Reliability, sensitivity and validity is insufficiently investigated for many of the commercial available screening-devices based on a PC.

Color Perception Tests↗

PubMed1998

Visual function and gene analysis in a family with Oguchi's disease.

A family with 1 case of retinitis pigmentosa (III-1) and 2 cases of Oguchi's disease (III-2, 3) was examined in terms of electrophysiology as well as molecular biology. The proband (III-3), a 42-year-old female, and 2 older brothers (III-1, 2, aged 52 and 45 years) and 2 unaffected members in the same family participated in this study. Corrected visual acuities of the individuals with Oguchi's disease (III-2, 3) were 1.2. On funduscopy, blood vessels stood out in relief against a metallic-appearing background and a Mizuo-Nakamura phenomenon was evident. Full-field electroretinograms (ERGs) recorded from the proband were indicative of rod dystrophy, but results of other electrophysiological examinations (multifocal ERG, pattern ERG and visual-evoked cortical potential recordings) were within normal limits. Patient III-1 had corrected visual acuities of RE 20 cm/m.m. and LE 30 cm/n.d., severe chorioretinal atrophy in both fundi, and full-field ERG revealed rod-cone dystrophy. Mutation of the arrestin gene (1147de1A) was detected in all 3 patients. Visual function in each patient coincides with that of retinitis pigmentosa or Oguchi's disease, respectively.

Adult↗

PubMedDate not supplied

Maintaining instrument quality while reducing items: application of Rasch analysis to a self-report of visual function.

While efficiency has been of concern in the measurement of health care outcomes, little attention has been devoted to methods that achieve efficient, shortened instruments that have good psychometric properties. The purpose of this study was to show how Rasch analysis could be used to reduce the number of items in an instrument while maintaining credible psychometric properties. This approach was applied to the Visual Function-14 (VF-14), a self-report of 14 vision-dependent activities, designed to measure the need for and outcomes of cataract surgery. An instrument which contained the VF-14 plus an additional 10 items that were developed for the study (VF-24) was administered to sixty-one patients (73.7+/-9.5 years) about to undergo extracapsular cataract removal at one of two surgical centers. Rasch analysis (BIGSTEPS) of the VF-14 showed a number of limitations to the original instrument, including: 1) unequal use of the five rating categories, 2) ceiling effect, 3) several other gaps where patient abilities did not match with item difficulties, and 4) sets of items that appeared redundant, (i.e., having the same calibration level). To resolve the first three of these problems, the rating scale was converted to a three-point scale and BIGSTEPS was run with all 24 items. (10 additional items added to the VF-14 designed to "fill in" the gaps). The conversion to a three-point scale and the increase in items resulted in some improvement in the matching of item difficulty to patient ability, as evidenced by a slight decrease in gaps. The addition of items resulted in improvements in person separation (2.55 to 2.99) and Cronbach's alpha (.83 to .91) but did not substantially reduce the ceiling effect and furthermore resulted in an increase in item redundancy. The final practical improvement undertaken was to reduce the number of items while attempting to maintain the psychometric qualities of the instrument as a whole. Three criteria were used in deciding to remove items: 1) high mean square, 2) low mean square and 3) items having similar calibrations. In addition, if an analysis showed that the removal of an item substantially decrease person separation, that item was retained for further analyses. Relative to the original VF-14, the resulting VF-10 showed less redundancy of items while person separation (2.20) and Cronbach's alpha (.89) remained relatively intact. The study demonstrates that Rasch analysis, while effective in elucidating the metrics of an original instrument, can also be useful in designing modifications of instruments that are both efficient and psychometrically sound.

Cataract Extraction↗

PubMed2006

Hypotrichosis with juvenile macular dystrophy: clinical and electrophysiological assessment of visual function.

PURPOSE: To evaluate retinal function in subjects suffering from hypotrichosis with juvenile macular dystrophy (HJMD). DESIGN: Retrospective case-control study. PARTICIPANTS: Sixteen HJMD patients belonging to 2 genetic groups and 20 control subjects. METHODS: The HJMD patients underwent clinical ophthalmological examination and electrophysiological testing for a period of as many as 14 years. The electroretinogram (ERG), electro-oculogram (EOG), and visual evoked potential (VEP) were recorded serially to assess visual function and to follow possible progression of the disease. MAIN OUTCOME MEASURES: Amplitudes and implicit times of ERG and VEP, and Arden ratio of EOG. RESULTS: Fundus examination revealed pigmentary abnormalities with atrophic changes at the posterior pole extending to regions beyond the macular area. A slow and time-dependent decline in visual acuity was noted. The ERG responses were subnormal in amplitude. The ERG deficit was similar for light- and dark-adapted responses. There was a gradual but consistent decrease in the ERGs with time. The EOG measurements were within the normal range. Pattern reversal VEPs were very subnormal, even in patients with mild deterioration of visual acuity. The flash VEPs were of slightly subnormal amplitudes and implicit times in the upper limit of the normal range. CONCLUSIONS: The fundus pictures and electrophysiological tests were consistent with retinal involvement extending beyond the macular region. Follow-up of visual acuity and ERG testing indicated a slowly progressing retinal disorder affecting cone-mediated vision as well as rod-mediated vision. Therefore, we suggest that a more appropriate name for this syndrome is hypotrichosis with cone-rod dystrophy.

Adolescent↗

PubMedDate not supplied

[Effects of melatonin and motherwort tincture on the emotional state and visual functions in anxious subjects].

The chronic administration of melatonin (0.75 mg at night, 10 days) led to a significant decrease in the thresholds of retinal brightness sensitivity and improved the emotional state in anxious young subjects. Analogous changes were less pronounced after the treatment with common motherwort (Leonurus cardiaca) tincture. It is suggested that there is a relation between the limitation of anxiety and the improvement of visual function (sensitivity).

Adult↗

PubMed1992

ORG 2766 fails to improve visual functions in rats with occipital lesions.

Adult rats were trained on a white versus black card discrimination in a circular water tank. Three independent variables were manipulated: lesion (sham, lateral occipital, medial occipital), dose of ORG 2766 administered (0 or 25 micrograms in saline on alternate days for 18 days), and time of administration (during the post-surgical recovery interval or during post-operative testing). Both visual cortical lesions produced a prominent retention deficit and defective pattern vision. Neither post-surgical nor concurrent administration of ORG 2766 improved visual functions. These results, along with a growing body of evidence, challenge the generality of the positive influences of ORG 2766 upon behavioral recovery observed in animals with limbic lesions.

Adrenocorticotropic Hormone↗

PubMed2006

Cells isolated from umbilical cord tissue rescue photoreceptors and visual functions in a rodent model of retinal disease.

Progressive photoreceptor degeneration resulting from genetic and other factors is a leading and largely untreatable cause of blindness worldwide. The object of this study was to find a cell type that is effective in slowing the progress of such degeneration in an animal model of human retinal disease, is safe, and could be generated in sufficient numbers for clinical application. We have compared efficacy of four human-derived cell types in preserving photoreceptor integrity and visual functions after injection into the subretinal space of the Royal College of Surgeons rat early in the progress of degeneration. Umbilical tissue-derived cells, placenta-derived cells, and mesenchymal stem cells were studied; dermal fibroblasts served as cell controls. At various ages up to 100 days, electroretinogram responses, spatial acuity, and luminance threshold were measured. Both umbilical-derived and mesenchymal cells significantly reduced the degree of functional deterioration in each test. The effect of placental cells was not much better than controls. Umbilical tissue-derived cells gave large areas of photoreceptor rescue; mesenchymal stem cells gave only localized rescue. Fibroblasts gave sham levels of rescue. Donor cells were confined to the subretinal space. There was no evidence of cell differentiation into neurons, of tumor formation or other untoward pathology. Since the umbilical tissue-derived cells demonstrated the best photoreceptor rescue and, unlike mesenchymal stem cells, were capable of sustained population doublings without karyotypic changes, it is proposed that they may provide utility as a cell source for the treatment of retinal degenerative diseases such as retinitis pigmentosa.

Animals↗

PubMed1994

[Development of visual function in infants and children].

The development of P1 component of VEP was studied in 150 normal infants and children between the age of 2 weeks and 9 years. The results indicates that the VEP consists of simple positive waves within 8 weeks following birth, the latencies of P1 components shorten dramatically from 2 to 4 months, the development of the latencies of low, medium and high spatial frequencies of P1 components reaches adult levels in infants and children of 4 months, 4 years and 9 years, respectively and the VEP amplitudes of infants and children are significantly higher than those of adults. Based on the results of our research, the development of visual function can be divided into 3 phases: the first, within 4 months following birth; the second, 5 months to 4 years and the third, 5 to 9 years.

Child↗

PubMed2005

Vascular endothelial growth factor expression in the retinal pigment epithelium is essential for choriocapillaris development and visual function.

The choroid in the eye provides vascular support for the retinal pigment epithelium (RPE) and the photoreceptors. Vascular endothelial growth factor (VEGF) derived from the RPE has been implicated in the physiological regulation of the choroidal vasculature, and overexpression of VEGF in this epithelium has been considered an important factor in the pathogenesis of choroidal neovascularization in age-related macular degeneration. Here, we demonstrate that RPE-derived VEGF is essential for choriocapillaris development. Conditional inactivation of VEGF expression in the RPE (in VEGFrpe-/- mice) results in the absence of choriocapillaris, occurrence of microphthalmia, and the loss of visual function. Severe abnormalities of RPE cells are already observed when VEGF expression in the RPE is only reduced (in VEGFrpe+/- mice), despite the formation of choroidal vessels at these VEGF levels. Finally, using Hif1arpe-/- mice we demonstrate that these roles of VEGF are not dependent on hypoxia-inducible factor-1alpha-mediated transcriptional regulation of VEGF expression in the RPE. Thus, hypoxia-inducible factor-1alpha-independent expression of VEGF is essential for choroid development.

Animals↗

PubMed1998

Visual function in retinitis pigmentosa related to a codon 15 rhodopsin gene mutation.

To determine the phenotype of a Japanese family in which retinitis pigmentosa cosegregates with a rhodopsin gene mutation, i.e. an asparagine-to-serine change at codon 15 (Asn-15-Ser), 5 affected and 5 unaffected members of one pedigree underwent several ophthalmic examinations as well as Ganzfeld electroretinography (ERG) and multifocal ERG. Genomic DNA samples were analyzed by PCR amplification, sequencing and restriction enzyme digestion. A codon 15 rhodopsin gene mutation (Asn-15-Ser) was found in all affected members. The region of pigmentary degeneration was localized in the lower hemiretina, and visual field defects corresponded to the retinal pigmentary changes. Scotopic ERG amplitudes, rather than photopic ERG amplitudes, were reduced. Multifocal ERG revealed a low magnitude of response density, even for the upper hemiretina, which showed no bony corpuscle pigmentation. Visual function in sectorial retinitis pigmentosa associated with rhodopsin gene codon 15 mutation is on the basis of the rod-cone dystrophy, regardless of differences in phenotypic expression.

Adult↗