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PubMed2005

Relationship of cataract symptoms of preoperative patients and vision-related quality of life.

BACKGROUND: This study was conducted in an attempt to describe the status of cataract symptoms of preoperative cataract patients, as well as to determine the relationship between cataract symptom and vision-related quality of life measures. RESEARCH DESIGN: A cross-sectional study design was used. Study subjects were selected using non-probabilistic methods. The study sample consisted of 132 patients scheduled for cataract surgery in one eye. Information was obtained from study subjects by conducting face-to-face interviews. PARTICIPANTS: Study subjects were adult cataract patients at Samsung and Kunyang General Hospitals in Seoul, Korea, and Tulane University Hospital and Clinics in New Orleans, Louisiana, United States of America. MEASUREMENTS: Degree to which study subjects were "bothered" by cataract symptoms was measured by using the 5-item Cataract Symptom Scores (CSS). The number of symptoms, highest scored symptom among the five, number of symptoms extremely bothering, and the mean of cataract symptom score were created based on the CSS measure. Vision-related quality of life was assessed by using the Visual Function 14 Items (VF-14) and Global Measure of Vision (GMV) for trouble and satisfaction. RESULTS: The symptoms "blurry vision" and "worsening of vision" were most frequently reported. The symptom "colors looking different" was rarely reported among preoperative cataract patients. The degree to which study subjects were bothered by "blurry vision" and "seeing glare, halo, or rings" was highly associated with visual function, visual trouble, and visual satisfaction. Multiple regression analysis revealed that the newly developed cataract symptom-related scales, as well as total amount of degree to which study subjects were "bothered" by symptoms were highly related to vision-related quality of life measures. These relationships were persistent after controlling for major socio-demographic variables. CONCLUSIONS: The results indicate that cataract symptoms are highly associated with vision-related quality of life. The results also suggest that the number of symptoms, highest scored symptom among the five, number of symptoms extremely bothering, and the mean cataract symptom scores should be considered an important cataract symptom-related scale when analyzing quality of life, including cataract symptom.

Aged↗
PubMed1993

Visual memory and visual spatial functions in the rat following parietal and temporal cortex injuries.

Adult rats were prepared with either posterior parietal, temporal, or sham neocortical lesions, and after assessing gross locomotor functions, trained in cognitive visual tasks. Training was conducted in a modified circular water maze wherein the water was made opaque with a white nontoxic powder paint. The order of the tasks was counterbalanced within groups. One task was a visual matching-to-sample problem with an intertrial interval of 20 s. The second task was a visual spatial conditional problem in which visual stimuli (white or gray cards) cued spatial choices in a T maze that was inserted into the tank. After completing these tasks, the animals were trained on a simple visual pattern discrimination and a simple position habit. Both lesion groups demonstrated significant deficits on both cognitive tasks. Since gross visual perceptual, spatial, and motor abilities were found to be unaffected by the lesions, it is suggested that a generalized retardation in cognitive functions follows injuries in these sites. Also, qualitative evidence supported the conclusion that posterior parietal cortex plays an important role in integrating visuospatial stimuli with motor responses.

Animals↗
PubMed2006

Potentiation of cortical inhibition by visual deprivation.

The fine-tuning of circuits in sensory cortex requires sensory experience during an early critical period. Visual deprivation during the critical period has catastrophic effects on visual function, including loss of visual responsiveness to the deprived eye, reduced visual acuity, and loss of tuning to many stimulus characteristics. These changes occur faster than the remodelling of thalamocortical axons, but the intracortical plasticity mechanisms that underlie them are incompletely understood. Long-term depression of excitatory intracortical synapses has been proposed as a general candidate mechanism for the loss of cortical responsiveness after visual deprivation. Alternatively (or in addition), the decreased ability of the deprived eye to activate cortical neurons could be due to enhanced intracortical inhibition. Here we show that visual deprivation leaves excitatory connections in layer 4 (the primary input layer to cortex) unaffected, but markedly potentiates inhibitory feedback between fast-spiking basket cells (FS cells) and star pyramidal neurons (star pyramids). Further, a previously undescribed form of long-term potentiation of inhibition (LTPi) could be induced at synapses from FS cells to star pyramids, and was occluded by previous visual deprivation. These data suggest that potentiation of inhibition is a major cellular mechanism underlying the deprivation-induced degradation of visual function, and that this form of LTPi is important in fine-tuning cortical circuitry in response to visual experience.

Animals↗
PubMed1998

Self-assessment of the quality of vision: association of questionnaire score with objective clinical tests.

PURPOSE: To investigate the association of a quality of life-visual function questionnaire with an objective clinical test of visual function. METHODS: We have developed a questionnaire to assess self-reported visual satisfaction in ophthalmic patients suffering from chronic eye conditions causing visual impairment. The questionnaire was administered to 120 patients suffering from age-related cataract, chronic open angle glaucoma, age-related macular degeneration, branch retinal vein occlusion, and presbyopia or minor refractive defects. All the participants also underwent determination of visual acuity, contrast sensitivity, glare, and visual field. RESULTS: The questionnaire has a good reproducibility, a high internal consistency, and is able to discriminate between the different groups of patients. The total questionnaire score is significantly associated with the results of all visual function tests with the exception of glare. When entered into a multiple linear regression model, near visual acuity and contrast sensitivity are still considerably associated with the total questionnaire score. The psychological attitude of the patient towards his/her health problem is also associated with the total average score. CONCLUSIONS: Overall, the model explains 49% of the variance in the average questionnaire score.

Adult↗
PubMed2005

Age-related eye disease, quality of life, and functional activity.

OBJECTIVE: To examine the associations of measures of quality of life (Medical Outcomes Study Short Form Health Survey) and functional activities (activities of daily living, instrumental activities of daily living, and visual function) in persons with and without age-related eye diseases. METHODS: Two thousand, six hundred seventy persons participated in the 1998 through 2000 examinations of both the Beaver Dam Eye Study and the Epidemiology of Hearing Loss Study. Age-related eye disease (age-related maculopathy, cataract, diabetic retinopathy, glaucoma, macula edema, occlusions, amblyopia, and macular holes) were assessed by fundus, slitlamp, and retroilluminated photographs and self-reported ocular history. Also administered was a standard interview that included the Medical Outcomes Study Short Form Health Survey, activities of daily living, instrumental activities of daily living, and visual function questionnaires and information on other medical conditions. RESULTS: After controlling for age and sex, we found that persons with an age-related eye disease had decreased scores in almost all the domains of the Medical Outcomes Study Short Form Health Survey, and persons with eye disease in both eyes had poorer scores than persons with eye disease in only 1 eye. Stratifying by age-related maculopathy and central cataract yielded similar results. Further adjustment for current visual acuity and the number of comorbid conditions explained most associations. Several of the mental scales were still marginally significantly lower (P<.10) in persons with age-related maculopathy after adjustment. Persons with an age-related eye disease were not more likely to have impaired activities of daily living or instrumental activities of daily living. After adjustment for current visual acuity and number of comorbidities, persons who had trouble reading small print or recognizing people across the street were more likely to have an age-related eye disease. Otherwise, there were no significant associations with the visual function questions and any of the specific ocular conditions. CONCLUSIONS: Many measures of general quality of life and functional activities were related to age-related eye diseases, but few associations remained significant after adjustments for vision and other comorbidities. Our data are compatible with the notion that decreased visual function, irrespective of the pathologic reason for the decrease, is associated with diminished quality of life and functional activities of living.

Activities of Daily Living↗
PubMed2003

GABA and its agonists improved visual cortical function in senescent monkeys.

Human cerebral cortical function degrades during old age. Much of this change may result from a degradation of intracortical inhibition during senescence. We used multibarreled microelectrodes to study the effects of electrophoretic application of gamma-aminobutyric acid (GABA), the GABA type a (GABAa) receptor agonist muscimol, and the GABAa receptor antagonist bicuculline, respectively, on the properties of individual V1 cells in old monkeys. Bicuculline exerted a much weaker effect on neuronal responses in old than in young animals, confirming a degradation of GABA-mediated inhibition. On the other hand, the administration of GABA and muscimol resulted in improved visual function. Many treated cells in area V1 of old animals displayed responses typical of young cells. The present results have important implications for the treatment of the sensory, motor, and cognitive declines that accompany old age.

Aging↗
PubMed1991

Age-related eye disease, visual impairment, and driving in the elderly.

As people age, a number of visual functions such as acuity, visual field, and night vision deteriorate. This decline in vision is associated in part with an increase in vehicular accidents per mile driven by the elderly. Four age-related ocular conditions--cataract, macular degeneration, open-angle glaucoma, and diabetic retinopathy--are primarily responsible for the decline in visual acuity and visual field in the elderly. Few epidemiologic data are available about these diseases, and at present they cannot be prevented. There is need for more information about visual decline and how it affects driving performance and for development of pragmatic approaches for detecting and assessing the elderly driver with functional visual deficits.

Accidents, Traffic↗
PubMedDate not supplied

Associations between specific measures of vision and vision-related quality of life in patients with bothnia dystrophy, a defined type of retinitis pigmentosa.

PURPOSE: To assess the relationship between objective tests of visual function and vision-related quality of life in patients with Bothnia dystrophy (BD), a retinal dystrophy of retinitis pigmentosa type with progressive maculopathy. METHODS: Forty-nine patients were tested. Weighted distance logMAR visual acuity (WVA), weighted logMAR low contrast VA (WCS), and binocular visual field (VF) areas were calculated. Vision-related quality of life (VRQL) was assessed using the 25-item National Eye Institute-Visual Function Questionnaire (NEI-VFQ-25). Correlation statistics were used and adjusted analyses of the relationship between the composite score and the objective visual function tests were performed with multiple linear regression. RESULTS: VRQL was significantly correlated with age, WVA, WCS, and binocular VF areas (P < 0.001). Calculation of partial correlation coefficients showed age to be significantly correlated only with VF (V-4-e) area (P < 0.0001). Multiple linear regression analyses revealed age and WVA to be significantly associated with the NEI-VFQ-25 composite score (P < 0.02 and P = 0.001, respectively). WVA alone was the strongest predictor of self-reported experience of total visual function in BD patients (r 2= 0.69). CONCLUSIONS: A strong relationship between objective tests of visual function and patient perceived VRQL as assessed by a questionnaire was found. WVA was the strongest predictor and together with age explained almost 70% of the variability of the composite score of the questionnaire.

Adolescent↗
PubMedDate not supplied

Long-term outcome after conservative treatment of indirect traumatic optic neuropathy.

PURPOSE: To report the long-term outcome of patients with indirect traumatic optic neuropathy (TON) which showed useful vision for a short period after trauma. METHODS: A cohort of 12 TON patients treated with steroids megadose immediately after trauma was followed every 6 months for an overall period of 5 years. Other than a full neuro-ophthalmologic examination, each visit included quantitative Goldmann perimetry and pattern reversal visual evoked potentials. The results of each examination were compared with the visual function at baseline. The main outcome measures were visual acuity and visual field. Data were analyzed using the Wilcoxon signed-rank test. A p value of less than 0.05 was considered statistically significant. RESULTS: All patients showed a stable visual function 5 years after optic nerve trauma. There was no difference in visual acuity levels (p=0.65) and no visual field surface area between the visit at baseline and the last follow-up. However, a significant improvement in visual field extension (p=0.036) was observed after perimetry evaluation. CONCLUSIONS: This cohort of patients clearly demonstrates that the residual visual function found in the short term after TON is maintained for at least 5 years. These findings add further important clinical information for patients with TON. Furthermore, these data may be helpful to better quantify morbidity related to optic nerve trauma and its permanent sequelae.

Adult↗
PubMed1999

Genetic dissection of behavior: modulation of locomotion by light in the Drosophila melanogaster larva requires genetically distinct visual system functions.

The Drosophila larva modulates its pattern of locomotion when exposed to light. Modulation of locomotion can be measured as a reduction in the distance traveled and by a sharp change of direction when the light is turned on. When the light is turned off this change of direction, albeit significantly smaller than when the light is turned on, is still significantly larger than in the absence of light transition. Mutations that disrupt adult phototransduction disrupt a subset of these responses. In larvae carrying these mutations the magnitude of change of direction when the light is turned on is reduced to levels indistinguishable from that recorded when the light is turned off, but it is still significantly higher than in the absence of any light transition. Similar results were obtained when these responses were measured in strains where the larval photoreceptor neurons were ablated by mutations in the glass (gl) gene or by the targeted expression of the cell death gene head involution defective (hid). A mutation in the homeobox gene sine oculis (so) that ablates the larval visual system, or the targeted expression of the reaper (rpr) cell death gene, abolishes all responses to light detected as a change of direction. We propose the existence of an extraocular light perception that does not use the same phototransduction cascade as the adult photoreceptors. Our results indicate that this novel visual function depends on the blue-absorbing rhodopsin Rh1 and is specified by the so gene.

Animals↗
PubMed1988

Visual-field function in pseudophakia.

An automated perimeter (Octopus 2000) was used to examine visual-field function in 52 pseudophakic eyes. Threshold sensitivity was reduced throughout the visual field by from 0.4 to 20.0 decibels from that of threshold sensitivity in age-matched normal eyes. This reduction was comparable to that seen in contact-lens-corrected aphakic eyes.

Aged↗
PubMed1999

Functional magnetic resonance imaging in the visual system.

Functional magnetic resonance imaging (fMRI) is a relatively new technique for measuring brain function during resting and activated conditions with good spatial and temporal resolution. Because of a robust and reproducible activation response to visual stimuli in the occipital cortex, many studies have been directed at visual function. The methodology has been refined progressively to allow more accurate detection of the small activation signal, and using computational mapping foci of cerebral activity have been displayed in a two-dimensional format. Several factors modifying the activation signal have been identified. fMRI has been used to define the retinotopic representation of areal boundaries and the localization of higher visual functions in the occipital cortex. Motion perception in area middle temporal (MT) is well-recognized, but eye movement studies are limited. The activated signal may have significant implications for our understanding of brain metabolism, but cerebral blood flow and oxygenation sensitive recordings after prolonged visual stimulation have given conflicting results. Clinically, fMRI can follow changes in cerebral activity during a progressive neurologic illness and measure responses to treatment. Neurosurgical planning in disorders such as epilepsy may be facilitated.

Color Perception↗
PubMed1989

[Aids for low vision--strategic approach].

There are currently methods to rehabilitate the remaining visual function of visually impaired people. Treatment stages and tests are based on classical physiology of vision and still remain strictly experimental. Recent investigations showed that the visual system, as a whole, operates as a space frequency analyzer. There are reception to each spatial frequency. They have to be assessed with accuracy before any rehabilitation attempting to develop channels which are still functional by elective stimulation. This stimulation must have a maximum determined energetic efficiency. The study of the Fourier spectrum on two different images demonstrates this possibility and starts opening the way for specific research.

Contrast Sensitivity↗
PubMedDate not supplied

Combining refractive error and uncorrected visual acuity to assess the effectiveness of refractive corneal surgery.

Residual refractive error and uncorrected visual acuity are two frequently measures used to assess the effectiveness of refractive corneal surgery. Nordan and colleagues have suggested a Visual Function Index which combines these two measures in one quantitative measure. This article presents a Visual Function Score for radial keratotomy which includes a set of qualitative categories (excellent, good, fair, poor) and specifies the clinical values for refractive error and visual acuity in each category. There was substantial agreement among ophthalmologists who reviewed the category definitions, and we think that the Visual Function Score improves our ability to objectively assess surgical outcome. Application of the score to the Prospective Evaluation of Radial Keratotomy (PERK) Study data yielded closer agreement with refractive error results than with visual acuity values. The Visual Function Score lowered the classification of eyes that were hyperopic but had sufficient accommodation to overcome so that a high visual acuity result could be achieved. The inclusion of astigmatism values would be an important next step in the development of composite measures for the assessment of refractive surgery. In the future, a multifactorial index or score may be used to estimate the outcome of reported surgical procedures.

Adult↗
PubMed1999

Recovery of visual field function in the optic neuritis treatment trial.

PURPOSE: To assess the pattern of recovery of the visual field of patients with optic neuritis and to determine whether all affected portions of the visual field recover similarly or certain portions of the visual field have greater recovery. METHODS: We reviewed the Humphrey Visual Field (Allergan-Humphrey Inc, San Leandro, California) data from the initial and 6-month examination for the involved and fellow eyes of patients enrolled in the Optic Neuritis Treatment Trial (ONTT). The average threshold for each patient was calculated for the entire tested field and for locations within concentric rings having a radius 3, 9, 15, 21, and 27 degrees from fixation. The absolute amount of improvement and percentage improvement in average threshold between entry and the 6-month follow-up examination were determined for each patient. These measurements were compared within the concentric rings to assess patterns of recovery. RESULTS: Patients with localized defects recovered 86%+/-20% of their initial defect in average threshold, whereas those having diffuse defects recovered an average of 85%+/-23%. The area about fixation had the greatest relative recovery of threshold (87%+/-21% at 3 degrees); the relative recovery decreased with increasing eccentricity from fixation (P<.01). CONCLUSIONS: Patients with optic neuritis have a marked return of visual field function that does not appear to differ between patients with diffuse or localized field defects. The reduced redundancy of axons in the periphery of the field compared with near fixation may be responsible for the greater relative recovery of threshold near fixation.

Fixation, Ocular↗
PubMed1994

Effects of posterior segment disorders on oscillatory displacement thresholds, and on acuities as measured using the potential acuity meter and laser interferometer.

Oscillatory displacement thresholds (ODTs) were measured in 67 subjects with clear ocular media, but known posterior segment disorders. The ability of these thresholds to assess reduced visual function, as quantified by visual acuity deficits, was compared with that of the Potential Acuity Meter (PAM) and the Rodenstock Retinometer (RR). ODTs were found to be sensitive to acuity deficits which were retinal/neural in origin. Despite the fact that interferometric acuities are, unlike ODTs, a measure of resolution, the RR proved no more accurate in assessing the level of letter acuity which existed than did ODT measurement. As would be expected, the PAM provided for the most accurate means of assessing non-optical visual acuity deficits. However, the PAM proved to be less useful in eyes with: very poor levels of acuity, and certain anomalous conditions. The results have implications for the relative ability of each of the three tests to identify reduced visual function behind cataract.

Adolescent↗
PubMed2004

Methylprednisolone treatment does not influence axonal regeneration or degeneration following optic nerve injury in the adult rat.

BACKGROUND: Methylprednisolone (MP) is often used to treat optic nerve injury. However, its effects in experimental crush injury have not been extensively evaluated. METHODS: Adult Sprague-Dawley rats were subjected to a standardized optic nerve crush injury. Animals were treated either with 30 mg/kg MP intravenous bolus followed by subcutaneous injections every 6 hours for 48 hours, or with a drug vehicle alone. RESULTS: The injury resulted in a partial loss of neuronal nuclei-labeled retinal neurons and a corresponding degeneration of axons distal to the injury. EDI-labeled macrophages accumulated at the site of lesion, phagocyting FJ-labeled axonal debris. Regenerative fibers expressing growth associated protein-43 were seen proximal to the lesion, but did not traverse the glial scar. Analysis of optic nerve function using visual evoked potentials showed typical signals in intact animals, which were abolished after injury in MP-treated and untreated animals. CONCLUSIONS: We did not detect any effects of MP on retinal cell survival, macrophage activity at the site of injury, axonal degeneration/regeneration, or visual function. These experimental results provide a physiologic underpinning for the lack of efficacy demonstrated in a large trial of MP treatment of clinical optic nerve injury.

Animals↗