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At least 631 records · Page 35Linked to original sources
PubMed2005

Self-assessed visual function for patients with posterior capsule opacification before and after capsulotomy.

PURPOSE: To describe the functional outcome, as defined using the Catquest questionnaire, for patients with posterior capsule opacification (PCO) after capsulotomy. METHODS: A total of 47 patients with PCO were examined before and 1 month after capsulotomy. In addition to the ophthalmic examination, Catquest was completed and a digital image of the posterior lens capsule acquired. RESULTS: Capsulotomy resulted in a good level of benefit, as defined using Catquest, for 77% of the patients. No subgroup of patients who derived an exceedingly good or poor level of benefit was identified. Disabilities in daily life, satisfaction with vision and symptoms of glare improved from treatment (p < 0.001, p < 0.001 and p = 0.002, respectively). The results were comparable with the benefits of cataract surgery. CONCLUSIONS: Self-assessed visual function as defined using Catquest improved after capsulotomy for the vast majority of patients with PCO. No group of patients with exceptionally good or poor levels of benefit could be identified with certainty. However, the majority of those with a poor outcome were elderly individuals with ocular comorbidity. The overall functional results from treatment of PCO were very similar to those achieved after cataract surgery.

Adult↗
PubMed2002

Recovery of visual functions in a mouse model of Leber congenital amaurosis.

The visual process is initiated by the photoisomerization of 11-cis-retinal to all-trans-retinal. For sustained vision the 11-cis-chromophore must be regenerated from all-trans-retinal. This requires RPE65, a dominant retinal pigment epithelium protein. Disruption of the RPE65 gene results in massive accumulation of all-trans-retinyl esters in the retinal pigment epithelium, lack of 11-cis-retinal and therefore rhodopsin, and ultimately blindness. We reported previously (Van Hooser, J. P., Aleman, T. S., He, Y. G., Cideciyan, A. V., Kuksa, V., Pittler, S. J., Stone, E. M., Jacobson, S. G., and Palczewski, K. (2000) Proc. Natl. Acad. Sci. U. S. A. 97, 8623-8628) that in Rpe65-/- mice, oral administration of 9-cis-retinal generated isorhodopsin, a rod photopigment, and restored light sensitivity to the electroretinogram. Here, we provide evidence that early intervention by 9-cis-retinal administration significantly attenuated retinal ester accumulation and supported rod retinal function for more than 6 months post-treatment. In single cell recordings rod light sensitivity was shown to be a function of the amount of regenerated isorhodopsin; high doses restored rod responses with normal sensitivity and kinetics. Highly attenuated residual rod function was observed in untreated Rpe65-/- mice. This rod function is likely a consequence of low efficiency production of 11-cis-retinal by photo-conversion of all-trans-retinal in the retina as demonstrated by retinoid analysis. These studies show that pharmacological intervention produces long lasting preservation of visual function in dark-reared Rpe65-/- mice and may be a useful therapeutic strategy in recovering vision in humans diagnosed with Leber congenital amaurosis caused by mutations in the RPE65 gene, an inherited group of early onset blinding and retinal degenerations.

Animals↗
PubMed1996

Long chain polyunsaturated fatty acids and visual function in preterm infants.

Electroretinograms (ERG) were recorded at 40 weeks post-conceptual age (PCA) in 18 infants born prematurely (25-32 weeks gestation). Fatty acid composition of plasma and red cell phospholipids was measured within 4 days of birth and at time of ERG testing, and detailed record was kept of dietary intake. Correlations were seen between percentage intake of breast milk and docosahexaenoic acid (DHA) in both plasma (r = 0.818, P < 0.0001) and red cells (r = 0.534, P = 0.035) and significant differences in fatty acid profiles were seen between infants receiving > 50% and < 50% breast milk. No difference was seen in retinal sensitivity between infants receiving > 50% or < 50% breast milk. A positive correlation was seen between scotopic (rod) b-wave implicit time on ERG and DHA in both plasma (r = 0.733, P = 0.001) and red cells (r = 0.502, P = 0.04). A positive correlation was seen between arachidonic acid and rod ERG amplitude (r = 0.565, P = 0.022) which may reflect the higher AA/DHA ratio in the developing retina. These data did not support our hypothesis that increased dietary DHA results in enhanced retinal maturation. Visual acuity measured at 40 weeks PCA and again 3 months later was similar between groups. While subtle relationships were demonstrated between long chain polyunsaturated fatty acids and visual function, all infants were felt to be within age-appropriate normal range at expected date of delivery and at 3 months corrected age.

Breast Feeding↗
PubMed2006

Ectopic expression of tyrosine hydroxylase in the pigmented epithelium rescues the retinal abnormalities and visual function common in albinos in the absence of melanin.

Albino mammals have profound retinal abnormalities, including photoreceptor deficits and misrouted hemispheric pathways into the brain, demonstrating that melanin or its precursors are required for normal retinal development. Tyrosinase, the primary enzyme in melanin synthesis commonly mutated in albinism, oxidizes l-tyrosine to l-dopaquinone using l-3,4-dihydroxyphenylalanine (L-DOPA) as an intermediate product. L-DOPA is known to signal cell cycle exit during retinal development and plays an important role in the regulation of retinal development. Here, we have mimicked L-DOPA production by ectopically expressing tyrosine hydroxylase in mouse albino retinal pigment epithelium cells. Tyrosine hydroxylase can only oxidize l-tyrosine to L-DOPA without further progression towards melanin. The resulting transgenic animals remain phenotypically albino, but their visual abnormalities are corrected, with normal photoreceptor numbers and hemispheric pathways and improved visual function, assessed by an increase of spatial acuity. Our results demonstrate definitively that only early melanin precursors, L-DOPA or its metabolic derivatives, are vital in the appropriate development of mammalian retinae. They further highlight the value of substituting independent but biochemically related enzymes to overcome developmental abnormalities.

Albinism↗
PubMed2006

Prospective randomized controlled trial of the effect of intracameral vancomycin and gentamicin on macular retinal thickness and visual function following cataract surgery.

PURPOSE: To investigate whether the use of vancomycin (20 microg/mL) and gentamicin (8 microg/mL) in the infusion fluid at the time of cataract surgery increases the incidence of macular thickening as measured with optical coherence tomography (OCT) following phacoemulsification. SETTING: A public teaching hospital in Western Australia. METHODS: Fourty-one patients (50 eyes) with cataracts between 50 and 85 years of age were randomized to receive no antibiotics in the infusion fluid at the time of cataract surgery (control group) or vancomycin (20 microg/mL) and gentamicin (8 microg/mL) in the infusion fluid (antibiotic group). Optical coherence tomography measurements were performed preoperatively and 1 day and 1 and 5 weeks postoperatively. A significant increase in macular thickness (mean of the central 1.0 mm diameter) on OCT was defined as 15 microm or greater. Five weeks postoperatively, the best corrected Snellen acuity and Pelli-Robson contrast sensitivity were measured. RESULTS: Twenty-five percent in the control group and 38% in the antibiotic group had a significant increase in macular thickness measured on OCT 5 weeks postoperatively (P = .34). The mean contrast sensitivity of patients with increased macular thickness on OCT was 1.26, and in those with no change it was 1.43 (P = .001). CONCLUSIONS: The use of intracameral vancomycin (20 microg/mL) and gentamicin (8 microg/mL) at the time of cataract surgery had no significant effect on macular thickness or visual function postoperatively. Overall, 31% of eyes showed an increase of 15 microm or greater in central retinal thickness. These patients had significantly reduced contrast sensitivity.

Aged↗
PubMed2000

[Visual function after pars plana lensectomy and intraocular lens implantation in dislocation of the lens into the vitreous body].

The authors evaluate the functional result of the surgery solving luxation of lenses into the vitreous body cavity with helping of pars plana lensectomia with implantation of intraocular lenses, they have been performed in The Department of Ophthalmology of The Teaching Hospital of The Charles University in Hradec Králové between February 1995 to February 1999. Our group consisted of 11 patients (11 eyes), 8 males and 3 females in the age from 28 to 81 years, with average age of 60 years, the patients were divided into 3 units. 1st unit is represented by 5 patients with traumatic luxation of lens into vitreous body cavity after its contusion with developing of the secondary glaucoma, in the 2nd unit there are 5 patients with this complication as a consequence of operation of cataract, the 3rd unit includes only 1 patient with the Marfan syndrome. Study proved the fact that due to using of new surgical methods it is possible to keep a satisfactory visual functions in patients with a serious eye complications.

Adult↗
PubMed2006

Neurosensory effects of chronic exposure to arsenic via drinking water in Inner Mongolia: II. Vibrotactile and visual function.

This study was designed to assess the effects of exposure to arsenic in drinking water on visual and vibrotactile function in residents of the Bamen region of Inner Mongolia, China. Arsenic was measured by hydride generation atomic fluorescence. 321 participants were divided into three exposure groups- low (non-detectable-20), medium (100-300) and high (400-700 microg/l) arsenic in drinking water (AsW). Three visual tests were administered: acuity, contrast sensitivity and color discrimination (Lanthony's Desaturated 15 Hue Test). Vibration thresholds were measured with a vibrothesiometer. Vibration thresholds were significantly elevated in the high exposure group compared to other groups. Further analysis using a spline regression model suggested that the threshold for vibratory effects is between 150-170 microg/l AsW. These findings provide the first evidence that chronic exposure to arsenic in drinking water impairs vibrotactile thresholds. The results also indicate that arsenic affects neurological function well below the 1000 microg/I concentration reported by NRC (1999). No evidence of arsenic-related effects on visual function was found.

Adolescent↗
PubMed1994

Improved visual function and attenuation of declines in health-related quality of life after cataract extraction.

OBJECTIVE: To measure the effect of cataract extraction and lens implantation on elderly persons' health-related quality of life and on their ability to perform visual activities. DESIGN: Evaluations of health status were conducted preoperatively and at 3 and 12 months after surgery on patients scheduled for cataract extraction. SETTING: Patients were enrolled from the General Eye Service of the Massachusetts Eye and Ear Infirmary and 33 Boston practices. PATIENTS: The cohort consisted of 464 patients aged 65 years or older who were identified from the surgical schedule of the Massachusetts Eye and Ear Infirmary. At 3 to 12 months after surgery, 458 (99%) of the participants were successfully contacted. Health-related quality of life data were available for 419 (90%) to assess changes after surgery. MAIN OUTCOME MEASURES: Ophthalmologic examinations were performed preoperatively and during the follow-up period. The Activities of Daily Vision Scale (ADVS) and the Medical Outcomes Study 36-item short from (SF-36) were administered before surgery and at 3 and 12 months postoperatively to assess changes in health status. RESULTS: At 12 months after surgery, 95% of patients had improved Snellen visual acuity, 80% had improved ADVS scores, but only 36% had improved SF-36 physical functioning. Average scores on seven of eight SF-36 subscales worsened at 12 months. Patients with improved ADVS scores had significantly smaller declines across all SF-36 dimensions except for role limitations due to emotional problems. CONCLUSION: Improved visual function after cataract surgery was associated with better health-related quality of life, suggesting that age-related declines in health may be attenuated by improvements in visual function.

Activities of Daily Living↗
PubMed1984

Retinal boundaries and visual function in gyrate atrophy.

Three patients with gyrate atrophy of the retina and choroid underwent fundus photoperimetry, the combination of fundus photography and visual field analysis within the same instrument, to examine the correspondence between the funduscopically observed, scalloped margin of remaining retina and the functional limit of the peripheral visual field. The results suggest that near the border between remaining retina and atrophic areas, visual sensitivity falls off quite rapidly, producing perimetric isopters that conform closely to the scalloped retinal margin. In some instances, visual function can be demonstrated in islands of remaining retina that are totally surrounded by atrophic areas. This study demonstrates the usefulness of fundus photoperimetry in following the course of degenerative retinal diseases.

Adult↗
PubMed2005

[Multiple factor analysis of visual function in hypermetropic children].

OBJECTIVE: To investigate the characteristics of hypermetropic children whose visual acuity (VA) is declined or accompanied by esotropia. METHODS: One hundred and ninety children were given optometry, strabismus degree and binocular vision measurement. RESULTS: Declined VA appeared in 170 children, while esotropia occurred in 173. Sixty-one got binocular single vision, 17 had fusion function, and 11 had stereoaculty. Spherical equivalent had a linear relationship with VA (P < 0.01), but not with the strabismus degree (P > 0.05). The influence factors of binocular vision were age of discovery, VA and the strabismus degree, while the stereoaculty was influenced by the strabismus degree, spherical equivalent and VA. CONCLUSION: Low VA and strabismus are the most common complaint in children. Ametropia and strabismus do great harm to juvenile binocular vision, and stereoaculty is damaged seriously. We suggest an early examination of visual function in children.

Adolescent↗
PubMed2003

[Impairment of safety in navigation caused by alcohol: impact on visual function].

BACKGROUND: So far in Germany, no legally binding standards for blood alcohol concentration exist that prove an impairment of navigability. The aim of our interdisciplinary project was to obtain data in order to identify critical blood alcohol limits. In this context the visual system seems to be of decisive importance. MATERIALS AND METHODS: 21 professional skippers underwent realistic navigational demands soberly and alcoholized in a sea traffic simulator. The following parameters were considered: visual acuity, stereopsis, color vision, and accommodation. RESULTS: Under the influence of alcohol (average blood alcohol concentration: 1.08 per thousand ) each skipper considered himself to be completely capable of navigating. While simulations were running, all of the skippers made nautical mistakes or underestimated dangerous situations. Severe impairment in visual acuity or binocular function were not observed. Accommodation decreased by an average of 18% ( p=0.0001). In the test of color vision skippers made more mistakes ( p=0.017) and the time needed for this test was prolonged ( p=0.004). CONCLUSIONS: Changes in visual function as well as vegetative and psychological reactions could be the cause of mistakes and alcohol should therefore be regarded as a severe risk factor for security in sea navigation.

Accidents↗
PubMed1995

Visual function in Rett syndrome.

The authors examined refractive error, pattern onset visual evoked potentials, ocular posture and they performed internal and external eye examinations in 11 subjects with Rett syndrome (aged between four and 24 years) and 18 normal controls (aged between six and 20 years). Substantial refractive errors were common in the Rett syndrome group. Spectacle correction had never previously been worn and glasses were provided where appropriate. No subjects had nystagmus or optic nerve pallor and only one was strabismic. All subjects had recognisable and reproducible pattern-onset VEPs and latencies and amplitudes did not differ significantly from those of the controls. All demonstrated VEP thresholds of at least 24'. In contrast to other populations with profound disabilities, people with Rett syndrome have good function of the afferent visual pathways and, in view of their substantial refractive errors, are likely to benefit from spectacle correction.

Adolescent↗
PubMed1976

[Several biochemical signs of loss and restoration of visual function].

With the aid of cytophotometry the author studied the cellular chemistry of neurons (according to the activity of glutamate dehydrogenase) in the III, IV and V layers of the visual cortex in rats during the period of rehabilitation of specific functions following long-term light deprivation. It was demonstrated that a 2-week stay of deprivated animals in conditions of usual light is accompanied by visible normalization of the glutamate dehydrogenase activity in the cortical neurons. However, a complete rehabilitation of the control level was not attained. The study demonstrated differences in the reactions of identical neurons in the IV and V layers to the rehabilitation of specific functions. It is being assumed that the rehabilitation of the visual function may be due to biochemical reconstructions in the monomodel and certain parts of the polymodal neurons in the visual cortex.

Animals↗
PubMed2002

A comparison of laser photocoagulation with cryotherapy for threshold retinopathy of prematurity at 10 years: part 1. Visual function and structural outcome.

OBJECTIVE: To assess visual and structural outcomes after laser photocoagulation and transscleral cryotherapy for threshold retinopathy of prematurity (ROP) after 10 years. DESIGN: Extended follow-up of a randomized controlled clinical trial. PARTICIPANTS: One hundred eighteen eyes from 66 patients were randomly assigned to receive either cryotherapy or laser photocoagulation for threshold ROP. Forty-four eyes from 25 patients were examined for 10-year follow-up evaluations. INTERVENTION: Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity, slit-lamp, and fundus examination; fundus photography; and B-scans (eyes with retinal detachments) were performed. Patients' histories were taken to elicit past amblyopia therapy. Based on fundus photographs, independent observers graded the degree of retinal dragging as none, mild, moderate, or severe. MAIN AND SECONDARY OUTCOME MEASURES: Best-corrected ETDRS visual acuity (BCVA). The degree of dragging was determined clinically and photographically. In addition, the presence of strabismus or amblyopia and/or any history of treatment for amblyopia were noted accordingly. RESULTS: Eyes treated with laser had a mean BCVA of 20/66 (Snellen equivalent), whereas cryotherapy-treated eyes had a mean BCVA of 20/182 (Snellen equivalent) (P = 0.015, n = 42). Compared with eyes treated with cryotherapy, eyes treated with laser photocoagulation were 5.2 times more likely to have a 20/50 or better BCVA (95% confidence interval, 1.37-19.8, n = 42). Eyes treated with cryotherapy were 7.2 times (95% confidence interval, 1.54-33.6, n = 33) more likely to develop retinal dragging compared with laser treatment. By linear regression analysis, ETDRS visual acuity was inversely proportionate to the degree of retinal dragging in both laser (r = -0.637, P = 0.006) and cryotherapy (r = -0.517, P = 0.040) treated eyes. Among the 21 patients with favorable outcomes in both eyes, 13 had strabismus (62%) and 6 had received amblyopia therapy (29%). Ptosis, loss of cilia, and cortical cataract were among probable treatment-related complications that were noted in this study. CONCLUSIONS: Overall, laser-treated eyes had better structural and functional outcome compared with eyes treated with cryotherapy.

Child↗
PubMed1998

[Testing basic visual functions in the evaluation of extrapyramidal side effects of antipsychotic agents].

One of the cornerstones of antipsychotic therapy is the evaluation of the effective dose that cause minimal extrapyramidal side effects. It is known that the visual system (e. g. the retina) contains dopaminergic cells similarly to the striatum where dopaminergic blockade is crucial in the induction of extrapyramidal symptoms. This rises the possibility that striatal functions can be tested by the evaluation of certain visual functions. This study compared the visual contrast-sensitivity of 20 schizophrenic patients on antipsychotic medication (9 patients were on risperidone, 9 on haloperidol, and 1-1 on zuclopenthixol and fluanxol treatment) to that of normal control subjects, and found significant impairment in the former group. The contrast-sensitivity impairments correlated with the severity of extrapyramidal symptoms. These results suggest that contrast-sensitivity measurements can be useful in the evaluation of neuroleptic threshold in the clinical practice.

Adult↗
PubMed1988

Altering body position affects intraocular pressure and visual function.

Intraocular pressure (IOP) can be altered by changing body position. This report describes two experiments evaluating variations in IOP, as well as neural functioning of the retina and visual cortex (as measured by pattern-reversal electroretinogram and visual evoked potential), associated with whole-body, head-down tilt. The subjects, ten per experiment, were visually normal with IOP less than 19. In the first experiment, IOP elevations were induced by varying the angle of tilt in discrete steps between +90 degrees (upright) and -90 degrees (inverted). In each position IOP was measured and significant elevations (up to 3x baseline) were noted. These elevations were maintained for 1 min during which simultaneous retinal and cortical biopotentials were measured. In the second experiment, 6 degrees head-down tilt was maintained for 2 hr during which time the IOP and both biopotentials were measured repeatedly. Our findings confirm the effect of body position of IOP, while also revealing that head-down tilt produces significant reductions in neurophysiological function at both the retinal and cortical levels. The neural effect is maximized when 6 degrees head-down tilt is maintained for 20 min.

Adult↗
PubMed1989

Prediction of visual function behind cataract using displacement threshold hyperacuity.

Visual acuity and displacement threshold hyperacuity were measured in a group of patients awaiting cataract extraction, and this was repeated several weeks subsequent to surgery. In addition, measurements were made on a group of patients with various ocular pathologies but without the presence of cataract. Displacement thresholds in the cataract group increased only slightly with the severity of the opacity. On the other hand, displacement thresholds for the pathology group showed a marked dependence upon visual acuity--the worse the acuity, the higher the threshold. This results in a clear distinction between vision loss due to optical factors (cataract) and retinal/neural factors. There was a good correlation between pre- and post-operative displacement thresholds in the cataract group, with post-operative thresholds being slightly better than pre-operative thresholds. The results suggest that this technique may offer patients a good indication of the likely quality of vision achieved following cataract extraction.

Aged↗