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PubMedDate not supplied

Longitudinal study of levodopa/carbidopa for childhood amblyopia.

To determine the tolerability and efficacy of levodopa/carbidopa combined with occlusion therapy for childhood amblyopia, a double-masked placebo-controlled randomized longitudinal study was performed on 10 amblyopic children between 6 and 14 years of age. Subjects received, on average, 20/5 mg levodopa/carbidopa or 20 mg of placebo three times per day combined with part-time occlusion over a 3-week period. Visual function was assessed by Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity charts and by contrast sensitivity. Tolerability was assessed by questionnaire, SMAC (standard laboratory tests; consists of a chem 20 and complete blood count [CBC]) analysis, and physical examination. Compliance with occlusion and capsule consumption were assessed by questionnaire and by capsule count, respectively. At the end of the dosing regimen, the levodopa/carbidopa group significantly improved in visual acuity by 2.7 lines and in mean contrast sensitivity by 72% in the amblyopic eye. The placebo group improved in visual acuity by 1.6 lines in the amblyopic eye. Tolerability and occlusion compliance were similar between groups; however, capsule ingestion compliance was significantly lower in the levodopa/carbidopa group. One month after the termination of treatment, the levodopa/carbidopa group maintained a significant 1.2-line improvement in visual acuity and 74% improvement in contrast sensitivity in the amblyopic eye. The placebo group did not maintain an improvement in visual acuity between the eyes. It is concluded that levodopa/carbidopa, at an average of 0.48/0.12 mg/kg, is well tolerated and, when combined with part-time occlusion, is efficacious in improving visual function in amblyopic children.

Adolescent↗

PubMed1979

A visual index of thyroid function.

A visual index of thyroid uptake (VITU) is introduced as a qualitative measure of thyroid trapping. This index is determined from the 20-minute 99mTc-pertechnetate scan by visually comparing the relative tracer uptake between the thyroid and salivary glands. Three categories are defined: low, normal and elevated. The VITU correctly identified the functional status of the thyroid in 94% of 123 patients studied and agreed with the 24-hour radioiodine uptake (RAIU) in 89%. The VITU is a very simple but highly accurate, reliable and reproducible test. It was primarily designed to complement other tests of thyroid function by contributing qualitative information about the thyroidal trapping mechanism, but it can also be useful in confirming blood tests of thyroid function in cases in which one would prefer to avoid 131I administration for RAIU studies.

Diagnostic Errors↗

PubMed1979

Visual-vestibular interactions: I. Influence of peripheral vision on suppression of the vestibulo-ocular reflex and visual acuity.

Legibility of head-fixed displays in some motion environments is partially dependent upon visual suppression of the vestibuloocular reflex (VOR). This study investigates the effects of differing relationships between peripheral background movement and whole-body motion on the VOR and on visual performance. The purpose of the study is to explore factors in motion environments that influence performance limits and to develop procedures of potential usefulness in evaluating interacting visual and vestibular function. Visual performance and visual suppression of the VOR were markedly different, depending upon the relative direction of peripheral background movement. Visual suppression of the VOR, and visual performance, were disrupted far more when vestibular inputs and peripheral optokinetic inputs were discordant than when they were concordant. Results have potential implications for head-up displays and suggest a procedure for evaluating visual/vestibular function.

Acceleration↗

PubMed2005

Evaluating cognitive functions with visual and auditory number assays and P300 in children with epilepsy.

This study was planned to evaluate cognitive functions, especially attention and immediate recall, in children with epilepsy by using P300 and neuropsychological tests, which included visual and auditory number assays. Fifty five patients with partial seizures, 45 patients with generalized seizures and 20 patients with intractable seizures were enrolled in the study. Twenty five healthy children were taken as the control group. The results were as follows: 1. P300 latencies were significantly longer in the intractable and partial groups when compared with the control subjects. 2. The duration of epilepsy, seizure frequency, cerebral imaging pathologies were not significantly correlated with delayed P300 latencies. 3. The results of the visual and auditory number assays test showed significant abnormalities when each of the three groups were compared with the normal controls. 4. Though some subgroups of the neuropsychological tests were correlated with the P300 latencies, an overall significant correlation was not present between them. So, we suggest that neuropsychological tests are more convenient for the assessment of cognitive functions in children with epilepsy than the P300 recordings.

Acoustic Stimulation↗

PubMed2006

Sungear: interactive visualization and functional analysis of genomic datasets.

UNLABELLED: Sungear is a software system that supports a rapid, visually interactive and biologist-driven comparison of large datasets. The datasets can come from microarray experiments (e.g. genes induced in each experiment), from comparative genomics (e.g. genes present in each genome) or even from non-biological applications (e.g. demographics or baseball statistics). Sungear represents multiple datasets as vertices in a polygon. Each possible intersection among the sets is represented as a circle inside the polygon. The position of the circle is determined by the position of the vertices represented in the intersection and the area of the circle is determined by the number of elements in the intersection. Sungear shows which Gene Ontology terms are over-represented in a subset of circles or anchors. The intuitive Sungear interface has enabled biologists to determine quickly which dataset or groups of datasets play a role in a biological function of interest. AVAILABILITY: A live online version of Sungear can be found at http://virtualplant-prod.bio.nyu.edu/cgi-bin/sungear/index.cgi

Algorithms↗

PubMed1977

The optic disc in glaucoma II: correlation of the appearance of the optic disc with the visual field.

Examination of stereoscopic optic disc photographs allowed accurate prediction of glaucomatous and normal fields to be made in 82 and 95% of eyes respectively and for visual field loss to be correctly located in upper and lower half in 83 and 91% of cases respectively. Despite this high correlation the existence of false positive and fale negative predictions means that the total reliance on optic nerve examination without visual field estimation in the evaluation of the glaucoma patient should not be made. Optic disc examination is too insensitive for long-term follow-up of visual function in a glaucoma patient. The high correlation between the state of the visual field and the optic disc means that, in the evaluation of the visual functions of a glaucoma patient, the appearance of the optic disc and the visual field should be in agreement.

Glaucoma↗

PubMed1988

Optic nerve decompression for osteopetrosis in early childhood.

Visual failure in osteopetrosis may result from retinal degeneration or compression of the optic nerve in the narrowed optic canals. We report the evaluation and treatment of five children with osteopetrosis whose optic nerve dysfunction seems to have been related to the latter etiology. Evaluation of visual function was carried out by means of behavioral observation and flash visual evoked responses. Of six nerves evaluated both pre- and postoperatively, the visual evoked responses seemed to improve in four. Three nerves were serially evaluated without an operation, and one showed changes consistent with maturation. One nerve was evaluated with serial postoperative evoked potentials and showed no change. We conclude that surgical decompression of the optic nerve in patients with documented optic nerve dysfunction and osteopetrosis allows improvement in visual function and is, therefore, an important consideration in the evaluation and management of patients with this disease.

Age Factors↗

PubMed1999

Yearly rates of rod and cone functional loss in retinitis pigmentosa and cone-rod dystrophy.

OBJECTIVE: To provide the first measures of the relative rates of rod and cone functional loss in patients with retinitis pigmentosa (RP) or cone-rod dystrophy (CRD). DESIGN: Five-year, prospective natural history study. PARTICIPANTS: Ninety-six patients (67 with RP and 29 with CRD) retaining measurable rod-mediated visual function and 5 normal subjects were tested at baseline and annually for 4 consecutive years. MAIN OUTCOME MEASURES: Tests of visual function included visual acuity, dark-adaptation thresholds, dark-adapted static perimetry, and rod and cone computer-averaged electroretinograms (ERGs), which were obtained over a range of retinal illuminances. Intervisit variability for each measure was obtained in a subset of patients who were tested twice within a 2-month interval and was used to determine whether an individual patient had shown progression, regression, or no change over a particular study interval. RESULTS: Over a 4-year interval, a significant number of patients with RP (60%) and CRD (62%) showed a decline in cone ERG amplitude. For rod ERG amplitude, the percentage of patients with RP or CRD showing progression was 64% and 45%, respectively. Although visual acuity, dark-adapted threshold, and rod visual field area also declined significantly over the 4-year period, the mean rate of change and the numbers of patients showing progression on these measures were lower than those for ERG measures. On specialized ERG testing, the yearly change in rod ERG threshold in RP was greater than the yearly change in cone ERG threshold, and the rate of progression varied significantly among inheritance types. For patients with CRD, the yearly change in rod threshold was comparable to the yearly change in cone ERG threshold. CONCLUSIONS: This study helps to define the natural progression of rod-mediated and cone-mediated functional loss in patients with RP and CRD.

Adolescent↗

PubMed1999

Correlation of the vision-related functional impairment associated with blepharoptosis and the impact of blepharoptosis surgery.

OBJECTIVE: To assess the effect of blepharoptosis on patients' visual function and health-related quality of life and to determine what measures are associated with postsurgical change in functional status. DESIGN: Prospective, observational case series. PARTICIPANTS: One hundred patients with unilateral or bilateral blepharoptosis. INTERVENTION/MAIN OUTCOME MEASURES: Preoperative and postoperative upper eyelid position (i.e., margin reflex distance [MRD]) and superior visual field (SVF) height, as well as subjective visual function and health-related quality-of-life functional status before and after ptosis surgery. RESULTS: There was a mean 30-point increase in functional index score after ptosis repair (P < 0.001). Lower (more ptotic) preoperative upper eyelid position and SVF (combined eye) were associated with greater change in functional index after surgery (r = -0.290, P = 0.007 and r = -0.39, P = 0.003, respectively). Preoperative visual field testing with manual lid elevation was not significantly correlated to the postoperative change in functional index (P > 0.100). The strongest correlation of postoperative functional index change was with the preoperative functional status (r = -0.79, P < 0.001). CONCLUSIONS: Patients' functional status is reduced by blepharoptosis, and surgical repair results in measurable increase in health-related quality of life. Patients' self-reported preoperative functional impairment is most strongly associated with the degree of postsurgical functional improvement.

Adult↗

PubMed1999

Luminance of the surround and visual fatigue of VDT operators.

Luminance distribution in the visual field is considered as one of causal factors with a significant influence on visual fatigue, especially for intensive and extended Video Display Terminal (VDT) work. The aim of the study was to define visual fatigue of VDT operators for different values of surrounding luminance. Experiments were carried out in laboratory conditions under 3 lighting conditions. Only 1 lighting parameter--the luminance of the wall behind the display (surrounding luminance)--changed. Visual fatigue was measured both by a subjective evaluation of different visual complaints (asthenopic symptoms) and by objective measurements of changes in the following visual functions: accommodation, convergence, habitual horizontal phoria, critical fusional frequency (CFF), and visual acuity. The same experiments were done for CRT (Cathode Ray Tube) and LCD TFT (Liquid Crystal Display with Thin Film Transistor) screens. The results of the study have shown that there was no significant influence of the value of surrounding luminance on the asthenopic symptoms for either type of screen. A general tendency towards bigger visual complaints for LCD TFT than for CRT participants was found. An objective evaluation of visual fatigue demonstrated a tendency towards bigger changes in visual functions with an increase of surrounding luminance for both screens. Statistical analysis of the results has shown that surrounding luminance influences significantly the reduction of the accommodation amplitude (significance level <.05).

Adolescent↗

PubMed1981

The effectiveness of cataract surgery. A retrospective study.

The outcome of intracapsular cataract extraction seen from the patients' point of view and patients' statements of visual function were obtained by questionnaires to 120 patients one year after the operation. Comparison to visual acuity at discharge after surgery was done. The results indicate that today cataract extraction is very successful in improving vision, visual function and quality of life. The utilization of the visual improvement, however, is not always optimal; e.g. 39% of those patients, who according to visual acuity at discharge should have normal reading capacities, do not or cannot utilize this ability. Many circumstances can be presumed to be responsible for this discrepancy, but further studies are needed for elucidation of these problems.

Activities of Daily Living↗

PubMed1999

Bilateral implantation of asymmetrical diffractive multifocal intraocular lenses.

OBJECTIVE: To evaluate visual results after bilateral implantation of multifocal intraocular lenses (IOLs) with asymmetrical light distribution for the far and near focus. METHODS: Twenty-nine patients underwent bilateral implantation of silicone-optic, foldable, diffractive IOLs in a prospective, 2-center, noncontrolled interventional study. Each patient had a distant-dominant multifocal IOL implanted in 1 eye and a near-dominant multifocal IOL implanted in the fellow eye. Refractive and visual results, including contrast acuity and binocular visual function, were determined. Patients were questioned for postoperative spectacle usage. RESULTS: Visual and contrast acuity in the dominant focus of either lens was superior to that in the nondominant focus at 3.5 to 12 months postoperatively, i.e., performance was best at distance for the distant-dominant and at near for the near-dominant lens. In binocular viewing, the monocular maximal results added up to an improved binocular visual performance. Binocular visual function was within normal limits. Eighty percent of patients reported no use of spectacles at any time postoperatively. CONCLUSIONS: Bilateral implantation of asymmetrical diffractive IOLs is an effective alternative for restoring simultaneous distance and near vision with a potential for improved contrast sensitivity compared with conventional multifocal IOLs.

Aged↗

PubMed2000

A controlled study of vigabatrin and visual abnormalities.

AIMS: To assess the visual function in epileptic patients who have received vigabatrin; to compare this with the visual function in similar epileptic patients who have never received vigabatrin; to investigate whether the severity of visual field defect (VFD) is related to the dose of vigabatrin; to consider other factors that may correlate with the severity of VFD. METHODS: 21 consecutive patients who had taken vigabatrin at some time in their lives were enrolled from the epilepsy clinic of the Royal Shrewsbury Hospital and were compared with a group of 11 otherwise similar patients with epilepsy who had never received vigabatrin. One patient taking vigabatrin was excluded from the study because her visual field results were unreliable because of multi-infarct dementia. 15 patients were taking vigabatrin at the time of the study (VC), the other five had taken vigabatrin some time in the past (VP). Each patient underwent static perimetry using either the two point or the three point full field 120 screening program on the Humphrey visual field analyser, followed by an ophthalmic examination to rule out ocular causes for VFDs. The visual fields from each patient were then analysed using a method devised to convert the VFD into percentage defect in both eyes. In patients with known cerebral pathology that may affect the visual pathway, only the unaffected homonymous hemifield was used. RESULTS: Nine of 20 (45%) patients in the vigabatrin group (VC and VP) complained of blurring of vision compared with two of 11 (18%) controls. Four patients (20%) in the vigabatrin group described flickering lights compared with one control (9%). None had a posterior vitreous detachment. Three of 30 (7.5%) eyes in the VC group had distant visual acuity of 6/12 or worse compared with three of 22 (9%) controls and five of 30 (16.7%) had near visual acuity worse than N6 compared with one of 22 (4.5%) in the control group. A mean of 1.73 Ishihara plates were misread in VC patients compared with 0.2 in the VP group and 0.18 in the controls. 11 of 15 (73.3%) patients in the VC group had greater than 10% VFDs as opposed to one of 11 (9.1%) controls (chi(2) test, p=0. 002). In 12 of 15 (80%) VC patients the percentage VFD was greater in the nasal hemifields than the temporal hemifields compared with six of 11 (54.5%) controls. Significant correlation was found between the severity of VFD and the total dose of vigabatrin ingested for the 20 patients exposed to vigabatrin (VC and VP: Spearman correlation coefficient=0.525; p=0.002), for the 15 patients taking vigabatrin at the time of examination (VC: Spearman correlation coefficient=0.568; p=0.002). CONCLUSION: This pilot study suggested that epileptic patients taking vigabatrin are at much higher risk of developing VFDs compared with epileptic patients on other antiepileptic drugs. The total ingested dose of vigabatrin correlated significantly with the severity of VFDs especially in those patients who had not stopped taking vigabatrin. In our group we found that those who had taken a total dose of 1500 g or more of vigabatrin were at risk of developing significant visual field defects.

Adult↗

PubMed1992

Central function and visual field damage in glaucoma.

82 eyes of 82 patients with different types of glaucoma were examined with various psychophysical tests assessing central and paracentral function, including foveal temporal contrast sensitivity function, FM 100-Hue test, and foveal and parafoveal blue-on-yellow-sensitivity. For all eyes visual field tests were performed with the Humphrey-Field-Analyzer, program 30-2. Global visual field indices were calculated as follows: Mean Sensitivity MS, Mean Deviation MD, and Corrected Pattern Standard Deviation CPSD. Linear regression analysis and multiple regression analysis correcting for a possible influence of age between the central and paracentral criteria and the global indices was performed. For the entire study population highly significant correlations are present between foveal and parafoveal blue-on-yellow-sensitivity and MS, MD and CPSD. Whereas in the Normal Tension Glaucoma subgroup (19/82 eyes) no significant correlations are found, the subgroup of 35/82 eyes with markedly elevated intraocular pressure (> or = 30 mmHg) shows highly statistically significant correlations between the low- and high-frequency end of the foveal temporal contrast sensitivity function and foveal and parafoveal blue-on-yellow-sensitivity and the global field indices. The results of the present study support the idea that there are two different mechanisms of glaucomatous damage, one which is pressure-dependent and one which may be pressure-independent. The pressure-dependent mechanism is responsible for deficits of central or paracentral function which are correlated to overall visual field damage.

Chronic Disease↗

PubMed1999

Outcome of cataract surgery considering the preoperative situation: a study of possible predictors of the functional outcome.

AIM: To analyse possible predictors of the self assessed functional outcome of a cataract extraction. METHODS: The patients' self assessed visual function was studied by use of a questionnaire, the "Catquest", before and 6 months after surgery. All patients (n=1933, mean age 75.5 years, 66.8% women) who were undergoing cataract surgery in March 1995, in 35 different departments of ophthalmology participating in the National Swedish Cataract Register, were included in the study. A routine ophthalmic examination was performed before and after surgery. The following preoperative variables were studied with regard to a possible relation to the outcome: age, sex, ocular comorbidity, best corrected preoperative vision (better eye), first or second eye surgery, other diseases with a need for long term medication, need for home help, need for subsidised travel by taxi. RESULTS: Ocular comorbidity was strongly related to a "no benefit" outcome after surgery (p= 0.005). Second eye surgery and young age was related to a "very good benefit" outcome after surgery (p=0.0001 and p<0.0001 respectively). CONCLUSIONS: Patients with an ocular comorbidity in the eye undergoing a cataract extraction were characterised by a significantly higher frequency of deteriorated self assessed visual function after surgery than patients with no ocular comorbidity. The highest degree of improvement was most frequently found in younger patients undergoing second eye surgery.

Adult↗

PubMed2003

Accelerated aging of senescence accelerated mice R-1 demonstrated by flash visually evoked cortical potentials.

To determine the physiological alterations of visual functions induced by aging, the latency of the N40 peak of the flash visual evoked cortical potentials at several stimulus frequencies were analyzed from senescence accelerated mice (SAM). The senescence prone (P-8) and senescence resistant (R-1) SAM lines were studied. In both the P-8 and ICR (the standard outbred albino laboratory mouse also called CD-1) mice, the peak latency was not significantly different at 6 and 12 months of age. In contrast, there was a prolongation of the peak latency in the R-1 line at 12 months compared to that at 6 months. We conclude that there is an acceleration of the aging process in the R-1 line for visually evoked responses. Thus, the R-1 line might be an independent line suited for the study of aging effects on visual functions.

Aging↗

PubMed2003

Visualization and functional consequence of pulmonary vascular impairment in patients with rheumatic diseases.

STUDY OBJECTIVES: Systemic rheumatic diseases impair the vasculature in lungs. The aim of this study was to visualize vascular impairment and determine its consequence on lung function. PATIENTS AND MEASUREMENTS: Seventy-two patients with rheumatic diseases were evaluated by pulmonary function tests, ventilation-perfusion scintigraphy, and thermography of the hands. The ventilation-perfusion mismatch of the lungs was visualized and quantified by calculating the ventilation-perfusion ratio (/) at each pixel. The microvascular impairment in fingers was assessed by the temperature difference between the nail fold and the dorsal hand. RESULTS: Patients with rheumatic diseases exhibited an increased / that distributed at the periphery of the lungs. The diffusing capacity of the lung for carbon monoxide (DLCO) decreased (mean [+/- SD], 76.4 +/- 27.4% of predicted) relative to the vital capacity (VC) [mean, 88.4 +/- 21.8% of predicted; p < 0.01] regardless of the presence or absence of interstitial lung disease (ILD). The distal-dorsal temperature difference showed colder fingers in patients with Raynaud phenomenon (mean temperature, - 0.6 +/- 2.1 degrees C) than in those without it (mean temperature, 0.3 +/- 1.5 degrees C) and significantly correlated with the ventilation-perfusion mismatch of the lungs both in patients with ILD (p = 0.04) and in those without ILD (p = 0.02). The ventilation-perfusion mismatch of the lungs significantly correlated with the relative reduction in DLCO evaluated by the percent DLCO/percent VC ratio both in patients with ILD (p < 0.01) and in those without ILD (p = 0.02). CONCLUSIONS: These results suggest that the periphery-distributed microvascular impairment in the lungs leads to ventilation-perfusion mismatch that functionally causes a relative reduction in DLCO in patients with rheumatic diseases. The reduction in DLCO relative to VC represents the vascular impairment in the lungs both in patients with ILD and in those without.

Female↗

PubMed1986

[Changes in the functional characteristics of cells of the Clare-Bishop zone after unilateral partial isolation of the cat neocortex].

Evoked single cell activity in the Clare-Bishop area of the cat neocortex was recorded after partial transection of subcortico-cortical connections. Both functional properties of visual, auditory and somatosensory responsive cells and their responses to electrical stimulation of the primary projection area were studied. A week after transection some neurons in the Clare-Bishop area on the operated site recovered their reactions to applied stimuli. Within the first week the sensitivity of the neurons in the intact hemisphere changed; all the recorded cells reacted to light; 80% of the cells had receptive fields that were situated in the contralateral part of the visual area; 62% of the cells reacted to somatosensory stimuli. A week after the operation the number of responsive cells decreased. The peculiar features of the neuronal compensatory reorganization in the Clare-Bishop area and its role in the recovery of visual function is discussed.

Animals↗