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PubMed2003

Eccentric correction for off-axis vision in central visual field loss.

BACKGROUND: Subjects with absolute central visual field loss use eccentric fixation and magnifying devices to utilize their residual vision. This preliminary study investigated the importance of an accurate eccentric correction of off-axis refractive errors to optimize the residual visual function for these subjects. METHODS: Photorefraction using the PowerRefractor instrument was used to evaluate the ametropia in eccentric fixation angles. Methods were adapted for measuring visual acuity outside the macula using filtered optotypes from high-pass resolution perimetry. Optical corrections were implemented, and the visual function of subjects with central visual field loss was measured with and without eccentric correction. RESULTS: Of the seven cases reported, five experienced an improvement in visual function in their preferred retinal locus with eccentric refraction. CONCLUSIONS: The main result was that optical correction for better image quality on the peripheral retina is important for the vision of subjects with central visual field loss, objectively as well as subjectively.

Adolescent↗

PubMed2001

Visual risk factors for crash involvement in older drivers with cataract.

BACKGROUND: The Impact of Cataracts on Mobility project has previously demonstrated that older drivers with cataract have an elevated risk of motor vehicle collision. OBJECTIVE: To examine what types of visual impairment serve as a basis of the increased crash risk of older drivers with cataract. METHODS AND DESIGN: A cross-sectional analysis was performed on 274 older drivers with cataract and 103 older drivers free of cataract recruited through 12 eye care clinics for the purposes of the Impact of Cataracts on Mobility project, a prospective study on driving mobility in older adults with cataract. Tests measured visual acuity, contrast sensitivity, and disability glare for each eye separately using habitual distance correction. The dependent variable was involvement in at least 1 state-recorded, at-fault vehicle crash during the 5 years prior to study enrollment. RESULTS: Logistic regression evaluated associations (odds ratios [ORs]) between visual function and crash involvement. Better and worse eye models defined on the basis of visual acuity were developed. Associations between each type of visual function and crash involvement were adjusted for age, sex, driving exposure, cognitive status, and other types of visual function. For both the better and worse eye models, contrast sensitivity was independently associated with crash involvement, whereas visual acuity and disability glare were not. Drivers with a history of crash involvement were 8 times more likely to have a serious contrast sensitivity deficit in the worse eye (defined as a Pelli-Robson score of 1.25 or less) than those who were crash-free (OR = 7.86; 95% confidence interval [CI], 1.55-39.79); this association was weaker for the better eye but still statistically significant (OR = 3.78; 95% CI, 1.15-12.48). Crash-involved drivers were 6 times more likely to have severe contrast sensitivity impairment in both eyes (OR = 5.78; 95% CI, 1.87-17.86) than crash-free drivers. A severe contrast sensitivity deficit in only 1 eye was still significantly associated with crash involvement (OR = 2.70; 95% CI, 1.16-6.51). CONCLUSION: Severe contrast sensitivity impairment due to cataract elevates at-fault crash risk among older drivers, even when present in only 1 eye.

Accidents, Traffic↗

PubMed1992

Minimized surgery for retinal detachments with segmental buckling and nondrainage. An 11-year follow-up.

A prospective study was conducted of 107 retinal detachments operated on between August 1979 and January 1980, with a complete follow-up period ranging from 11 years to 11.5 years. Proliferative vitreoretinopathy (PVR) stage C1 or C2 was seen in 16 detachments. Surgery consisted of cryopexy and segmental buckling (limited to the area of breaks) with nondrainage. Of the surgical procedures, 71% were radial buckles, 19% circumferential, and 10% radial combined with circumferential buckles. The primary reattachment rate was 92.6%, and 97% after reoperation. During the long-term follow-up period, redetachment occurred in 12.1% of the eyes: 5.6% were classified as early redetachments (between 2 and 4 months), and 6.5% as late redetachments (between 3 and 7 years). Early redetachment was caused by PVR, and late redetachment by new holes. After reoperation, reattachment occurred in 92.6% of the eyes. The predominant cause of final failure was PVR (3.7%). Only one eye had two reoperations. There was a highly significant (P less than 0.001) improvement between preoperative visual function (mean 0.32) and postoperative visual function (mean 0.56) in all 99 reattached eyes during the follow-up period (Mann-Whitney U test).

Adolescent↗

PubMed2006

Quality of life after iodine 125 brachytherapy vs enucleation for choroidal melanoma: 5-year results from the Collaborative Ocular Melanoma Study: COMS QOLS Report No. 3.

OBJECTIVE: To describe health- and vision-targeted quality of life following treatment with iodine 125 brachytherapy vs enucleation for choroidal melanoma in a subgroup of patients who were treated and observed prospectively as part of a large randomized clinical trial. MAIN OUTCOME MEASURES: Difficulty with driving, near vision activities, and activities using stereopsis or binocularity; anxiety; and depression. PARTICIPANTS: Two hundred nine patients who enrolled in the Collaborative Ocular Melanoma Study trial for medium-sized tumors between March 1995 and July 1998 and gave informed consent prior to randomization to participation in an ancillary study of quality of life. METHODS: Patients were interviewed by telephone by a trained interviewer from the Collaborative Ocular Melanoma Study Coordinating Center at baseline (prior to randomization), at 6 months, and on annual anniversaries of enrollment. The questionnaire battery included the Medical Outcomes Study Short Form 36, the Activities of Daily Vision Scale, the National Eye Institute Visual Function Questionnaire, and the Hospital Anxiety and Depression Scale. Additional questions concerning satisfaction with posttreatment appearance and concerns about cancer recurrence also were included in posttreatment interviews. RESULTS: There was a significant increase in both treatment groups in levels of reported difficulty for most vision-oriented activities, and in bodily and ocular pain, 6 months following treatment. Differences in visual function between treatment groups reported during follow-up were relatively small, but significant differences favoring brachytherapy-treated patients were observed for driving during the first year of follow-up and for peripheral vision during the first 2 years of follow-up. Anxiety levels in both groups decreased significantly following treatment, but patients treated with brachytherapy with symptoms of anxiety were less likely to report later resolution of symptoms than patients with symptoms of anxiety who were treated with enucleation. This study was unable to assess impact of treatment on satisfaction with appearance and concern about cancer recurrence during the first year after treatment, but no treatment-related differences were found on these measures at 2 years and later follow-up times. CONCLUSIONS: Patients treated with brachytherapy reported significantly better visual function than patients treated with enucleation with respect to driving and peripheral vision for up to 2 years following treatment. Differences between treatments in visual function diminished by 3 to 5 years posttreatment, paralleling decline in visual acuity in brachytherapy-treated eyes. Patients treated with brachytherapy were more likely to have symptoms of anxiety during follow-up than patients treated with enucleation. APPLICATION TO CLINICAL PRACTICE: Given that no significant differences in survival between enucleation and brachytherapy have been found, the differences demonstrated here for driving and anxiety will allow the individual patient and physician to make informed choices regarding treatment based on personal preferences.

Activities of Daily Living↗

PubMed2002

Assessment of vision-related function in patients with age-related macular degeneration.

OBJECTIVE: To investigate the validity of the visual function index (VF-14) in assessing visual function in patients with age-related macular degeneration (AMD). DESIGN: Prospective noncomparative observational case series. PARTICIPANTS: One hundred fifty-nine consecutive patients attending a sole practitioner's academic retina-only clinic from May 1998 through August 1998 and from May 1999 through August 1999. MAIN OUTCOME MEASURES: Correlations were calculated between the VF-14 scores and the medical outcomes study 36-item short form (SF-36), weighted comorbidity scale, visual acuity and clinical AMD severity (stage), and vision self-assessment scales. Documentation of the severity of macular degeneration was performed by a sole examiner. RESULTS: There was a moderately strong correlation between visual acuity and trouble with vision (r = 0.51), satisfaction with vision (r = -0.50), and overall quality of vision (r = -0.56). A strong correlation was noted between VF-14 score and patients' self-rating of amount of trouble with vision (r = -0.67), satisfaction with vision (r = 0.62), and overall quality of vision (r = 0.67). In comparison, correlations between SF-36 score and patients' self-rating of amount of trouble with vision, satisfaction with vision, and overall quality of vision ranged from r = 0.37 to r = -0.40. Linear regression analysis for the overall study population indicated that AMD severity was not an independently significant predictor of VF-14 score after adjusting for visual acuity. However, among patients with 20/20 vision in the better eye, AMD severity was an independently significant predictor of VF-14 score after adjusting for visual acuity in the worse eye. CONCLUSIONS: The VF-14 exhibits a considerable degree of validity as a measure of functional impairment in patients with AMD. Age-related macular degeneration severity was an independently significant predictor of VF-14 score in the group of patients with 20/20 vision in the better eye, but this did not hold true for the overall study population. Age-related macular degeneration is associated with substantial impairment in reported visual function.

Aged↗

PubMed2026

Guidance (challenges and priorities) in the assessment of children with low vision: ERN-EYE clinical consensus statement.

Across Europe, children living with low vision often face inconsistent approaches to the assessment of their visual function, leading to delays in diagnosis and unequal access to care. To address this gap, a multidisciplinary group of experts from 8 European countries developed a clinical consensus statement (CCS), using a modified Delphi process. This CCS provides guidance on evaluation of primary visual functions in children with low vision, regardless of etiologies. Assessing visual function can be challenging and cannot be limited to testing visual acuity. It requires a comprehensive approach that takes into account the child's developmental age and necessary adjustments for vision loss. This consensus statement presents different validated tools to evaluate visual acuity, contrast sensitivity, visual field, and color vision. It provides practical guidance for their use across developmental stages, including infancy and in children with syndromic or neurodevelopmental conditions, and highlights the critical role of caregivers in ensuring reliable assessments. The recommendations emphasize the need for age-appropriate testing strategies, tailored adaptations for low vision and additional impairment, and the importance of early assessment to support timely habilitation and optimize developmental outcomes.

Assessment↗

PubMed1998

Effectiveness of cataract surgery in Barcelona, Spain site results of an international study. Barcelona I-PORT investigators. International Patient Outcomes Research Team.

OBJECTIVES: To describe the impact of cataract surgery on visual function and health status in terms of clinical indicators as well as perceived health and functional capacity, and to identify patient characteristics and differences in clinical management that might affect outcomes. SUBJECTS AND METHODS: Observational longitudinal study of a cohort of 218 patients aged 50 or older undergoing first eye cataract surgery. Patients were evaluated pre- and postoperatively by clinical examinations (visual acuity [VA], ocular and medical comorbidity) and standardized telephone interviews. Main outcome measures included: the VF-14 Visual Function Index, the Cataract Symptom Score (CSS), the Sickness Impact Profile (SIP), and global measures of patients' trouble and satisfaction with vision. RESULTS: Significant improvement in all outcomes measures were observed at 4 months postoperatively (P < 0.001). However, the proportion of improved patients varied according to the outcome considered: VA (87%), CSS (72%), VF-14 (62%), and SIP (38%). Patient characteristics associated with higher a level of improvement were: worse preoperative visual function (VA, CSS, VF-14) (P < 0.001), less ocular comorbidity (P < 0.05), less postoperative complications (P < 0.05) and better preoperative general health status (SIP) (P < 0.01). The differences in clinical management were not associated with the outcomes (effectiveness) of surgery. CONCLUSIONS: A large proportion of patients benefit from cataract surgery, the greatest gain corresponding to visual function rather than to general health status. Since effectiveness of surgery is unrelated to operative procedures, less costly practices (i.e., day case surgery and loco-regional anesthesia) should be promoted.

Aged↗

PubMed1975

The effect of yttrium-90 implantation on endocrine function and visual fields in patients with "functionless" pituitary tumors, with biopsy and radiological findings.

Thirty patients with symptoms from "functionless" pituitary tumours were treated by yttrium-90 implants, and we report here the effects on symptoms, pituitary function and visual fields. On biopsy, about a third of the tumours showed some hormone granules. In the sixteen fully assessed at 1 year, pituitary function was improved in 25%, unchanged in 62-5%, and reduced in 12-5%. Improvement was confined to those in whom gonadotrophin secretion was the only function impaired pre-implant. Visual field defects were present pre-implant in ten patients (twenty eyes); at 1 year post-implant these defects had lessened in 80% and deteriorated in only 5% of eyes. Subsequently, within 5 years of the implant the field defects had worsened or recurred in four patients, all with initially extensive suprasellar projection; further treatment was then given. Remineralization of the sella was seen after implantation in seven cases, with reduction in fossa size in five. Thus pituitary implantation appears to be a practicable and reasonably simple procedure suitable for the treatment of most cases of "functionless" pituitary tumour. The "supressive" doses of irradiation used are adequate to shrink most tumours without loss of pituitary function.

Adenoma↗

PubMed1992

The psychophysiological investigation of multiple personality disorder: review and update.

In 1984 Putnam reviewed the literature on the psychophysiological investigation of multiple personality disorder (MPD). Since his review, a large number of studies have been conducted and reported in the literature and at professional conferences. Currently, psychophysiologic differences reported in the literature include changes in cerebral electrical activity, cerebral blood flow, galvanic skin response, skin temperature, event-related potentials, neuroendocrine profiles, thyroid function, response to medication, perception, visual functioning, visual evoked potentials, and in voice, posture, and motor behavior. We review the new research on the psychophysiological investigation of MPD from published, unpublished, and ongoing studies, and we attempt to place current findings into a conceptual framework. We have noted findings from unpublished and ongoing studies, and, perhaps unfortunately, they represent a large amount of the data presently available. We conclude with a critical analysis of current research methodology and suggestions for future research.

Brain Mapping↗

PubMed2000

The advanced glaucoma intervention study, 6: effect of cataract on visual field and visual acuity. The AGIS Investigators.

OBJECTIVE: To investigate the effect of cataract on visual function and the role of cataract in explaining a race-treatment interaction in outcomes of glaucoma surgery. METHODS: The Advanced Glaucoma Intervention Study (AGIS) enrolled 332 black patients (451 eyes) and 249 white patients (325 eyes) with advanced glaucoma. Eyes were randomly assigned to an argon laser trabeculoplasty (ALT)-trabeculectomy-trabeculectomy sequence or a trabeculectomy-ALT-trabeculectomy sequence. From the AGIS experience with cataract surgery during follow-up, we estimated the expected change in visual function scores from before cataract surgery to after cataract surgery. Then, for eyes with cataract not removed, we used these estimates of expected change to adjust visual function scores for the presumed effects of cataract. In turn, we used the adjusted scores to obtain cataract-adjusted main outcome measures. MAIN OUTCOME MEASURES: Average percent of eyes with decrease of visual field (APDVF) and average percent of eyes with decrease of visual acuity (APDVA). RESULTS: Within the 2 months before cataract surgery, visual acuity was better in eyes of white patients than of black patients by an average of approximately 2 lines on the visual acuity test chart. Cataract surgery improved visual acuity and visual field defect scores, with the amounts of improvement greater when preoperative visual acuity was lower. Adjustments for cataract brought about the following relative reductions: for APDVF, a relative reduction of 5% to 11% in black patients and 9% to 11% in white patients; for APDVA, a relative reduction of 45% to 49% in black patients and 31% to 38% in white patients; and for the APDVF and APDVA race-treatment interactions, relative reductions of 25% and 45%, respectively. CONCLUSIONS: On average, visual function scores improved after cataract surgery. The findings of reduced race-treatment interactions after adjustment for cataract do not alter our earlier conclusion that the AGIS 7-year results support use of the ALT-trabeculectomy-trabeculectomy sequence for black patients and of the trabeculectomy-ALT-trabeculectomy sequence for white patients without life-threatening health problems. The choice of treatment should take into account individual patient characteristics and needs.

Adult↗

PubMedDate not supplied

Aberration analyses needed for FDA evaluation of safety and effectiveness of wavefront-guided refractive surgical devices.

PURPOSE: Manufacturers of refractive surgical lasers are seeking Food and Drug Administration (FDA) approval for refractive surgery based on wavefront measurements rather than manifest refractions. This article draws attention to the need for better understanding of the relationship between aberrations and visual function and better testing methods for evaluating safety and effectiveness of wavefront-guided refractive surgery. METHODS: Before U.S. market approval for a new medical device, the FDA must determine whether the manufacturer has provided reasonable assurance that the device is safe and effective for its intended use, based on valid scientific evidence. The issues discussed here are based on FDA reviewers' experiences in evaluating Investigational Device Exemption (IDE) and Premarket Approval (PMA) applications for wavefront-guided refractive lasers. RESULTS: Even an optimal wavefront correction can provide only a marginally greater visual function benefit than a conventional spherocylindrical correction in a normal eye. Actual benefits are even smaller or nonexistent because variability from uncontrollable sources (eg, healing, aging, accommodation, pupil size, or ocular biomechanical effects) are typically larger than the errors treated. The effects of higher order aberrations and aberration changes on visual function are complex and poorly understood. CONCLUSIONS: The FDA's need for better tools to assess safety and effectiveness of wavefront-guided refractive surgery has stimulated major research efforts within the vision, ophthalmic, and optometric research communities. More research is needed to better understand the relationship between aberrations and visual function, and to be able to predict the visual effects of specific aberration changes in individual eyes. This research would have been more appropriately done before rather than after clinical trials for wavefront-guided refractive lasers.

Cornea↗

PubMedDate not supplied

[Evaluation of retinal function following central serous retinopathy and diffuse epithelial retinopathy].

The so called "benign" central serous retinopathy is associated in healed forms with frequent and troublesome visual function impairment. The abnormalities are still more severe after diffuse retinal pigment epitheliopathy. Snellen visual testing is relatively imprecise index of visual function, so it does not permit to appreciate the subtle visual disturbances experienced by these patients. We evaluated visual function disability with static automatized perimetry and contrast sensitivity in 30 patients with diffuse epitheliopathy in a cicatricial phase. Colour vision was also evaluated by 16 patients after central serous retinopathy. The results of this study are examined and discussed.

Adult↗

PubMed2005

Attentional modulation of perceptual grouping in human visual cortex: functional MRI studies.

When presented with a complex visual scene, our visual system has to organize the discrete entities present into useful perceptual units. The current work investigated the neural substrates of perceptual grouping defined by Gestalt laws of proximity and similarity of shape, and whether the neural substrates underlying perceptual grouping are modulated by task relevance and spatial attention. In visual discrimination tasks, subjects identified the orientations of perceptual groups formed by proximity or similarity of local elements or alternatively identified colors of either dots around the grouped stimuli or the fixation cross. Using functional magnetic resonance imaging (fMRI), we identified that the calcarine cortex was involved in proximity grouping but not in the grouping process defined by similarity of shape. Moreover, we showed evidence that the neural correlates of proximity grouping in the calcarine cortex were weakened when the elements were of low task relevance and fell outside an attended area of field. The findings reveal the neural basis for basic grouping operations, as well as illustrating how attention and proximity grouping interact in human visual cortex.

Adult↗

PubMed1993

Color-naming and color-matching by preschool children as a function of visual field and sex.

The accuracy for both a color-naming and a color-matching task as a function of visual field and sex was investigated in preschool children. Subjects were 17 boys and 17 girls ranging in age from 4.4 to 5.6 yr. Each subject was tested on both tasks, for which the target stimuli were presented tachistoscopically. Accuracy measures for each task were obtained separately for both left and right visual fields. A two-factor (sex x visual field) analysis of variance with repeated measures on the visual-field factor showed a significant difference between the sexes on the color-naming task only. No significant difference between visual fields was found for either task. However, significant interactions between sex and visual field for both the color-naming and color-matching tasks were obtained. t tests for simple main effects showed a significant right visual-field advantage for girls in naming colors. Conversely, a significant left visual-field advantage for color-matching was found for boys. Also, on the color-matching task, significant sex differences were found for both visual fields when compared separately. Boys were more accurate for left and girls more accurate for right visual field. Boys performed in a more strongly lateralized fashion on the color-matching task than did the girls, supporting the notion of greater lateralization among males.

Age Factors↗

PubMed1981

[The function of visual imagery and effect of input modality in spatial transformation task by blind and sighted adults (author's transl)].

The function of visual imagery and the effect of input modality in spatial transformation task was examined in 24 blind and 18 sighted students. Early blind, late blind and blind-folded sighted persons were presented with the information about four objects which were placed randomly on a board. They identified those objects haptically (with touch and movement) or verbally. After a practice session with one object, the subjects were told to locate the position of the other three objects (simple reconstruction trials) and then, to imagine that he/she had moved to a position behind the other object and to make similar evaluation of the imagined position (perspective transformation trials). These groups were well matched in simple reconstruction. But on perspective transformation trials, a highly significant interaction between sight status and input modality was found. Input modality affected the blinds only. Their error rate was significantly higher than the sighted persons in verbal input condition. In haptically input condition, the blind did not differ from the sighted. These results suggest visual imagery plays a major role when there are few or no perceptual cues in which to evaluate a situation.

Adult↗

PubMed1995

Assessment of vision and visual attention in minimally responsive brain injured patients.

Sensory, motor, and cognitive assessment is a critical priority in the care of minimally responsive brain-injured patients. However, their inconsistent pattern of responding may interfere with the use of traditional forms of assessment such as the mental status or neurological examinations. In this article we describe a quantitative method, based on single-subject experimental design, for evaluating vision and visual attention in this patient population. In a series of randomized trials, combinations of a blank card, a colorful photograph, and no stimulus are presented to either or both visual fields while horizontal eye movements are observed. The relationship between the side and nature of the visual stimulus and the frequency of eye movements is analyzed to determine visual function in one or both eyes. We report six cases of minimally responsive patients assessed with this method. In case A, we show evidence of functional vision in both visual fields. Case B also shows functional fields, but with a monocular visual deficit. Cases C and D show a homonymous hemianopsia which, in case D, is further complicated by a monocular visual deficit. Finally, cases E and F show patterns of left and right visual extinction. Thus, this objective and quantitative method leads to conclusions about patients' visual function that are not readily apparent by clinical observation and that allow appropriate modifications in further assessment or treatment.

Adolescent↗

PubMed1978

[A developmental study of visual-motor function in cerebral palsied children (author's transl)].

The purpose of this study was to investigate whether the disorder in the visual-motor function of cerebral palsied children was affected by specific defects or by the distortion in perceptual motor system or by mere developmental lag in the function of recognition and reconstruction using the method of multiple choice and Shochi's Block Design Test (1971). The results were as follows : Cerebral palsied children's developmental lag in the function of recognition was not conspicuous but the development in the function of reconstruction was obviously inferior to that of normal children. There was the difference in reconstruction ability by children with the types of cerebral palsy and intellectual levels and design-constructive patterns. Those factors and the developmental lag cause visual-motor disorders.

Cerebral Palsy↗

PubMed2006

Visual restoration in cortical blindness: insights from natural and TMS-induced blindsight.

Unilateral damage to visual cortex of the parietal or occipital lobe can cause the patient to be unaware of contralesional visual information due to either hemispatial neglect or hemianopia. It is now known that both neglect and hemianopia result from the disruption of a dynamic interaction between cortical visual pathways and more phylogenetically primitive visual pathways to the midbrain. We consider the therapeutic implications of these cortical-subcortical interactions in the rehabilitation of hemianopia. We start with the pheonmenon of "blindsight", in which patients with hemianopia can be shown, by implicit measures of visual detection or discrimination, to process visual information without conscious awareness. Some variants of blindsight have been postulated to recruit subcortical processes, while others may reflect compensatory optimisation of processing of spared visual cortex. Both mechanisms may offer opportunities for innovative strategies for rehabilitation of visual field defects. We relate the neural mechanisms that have been proposed to underlie blindsight to those that have been suggested to underlie the recovery of visual function after rehabilitation. It is suggested that the similarity and overlap of the neural processes supporting blindsight and recovery of visual function might provide insights for effective rehabilitation strategies for restoring visual functions.

Animals↗