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PubMed1995

[Cognitive and visual functions in a sample of the aged population: analysis of evoked potentials].

BACKGROUND: There are significant changes of perception and cognition during aging. Goal of this study was to investigate these functions by means of evoked potentials, and to obtain normative data in older people for comparisons with cognitive disorders in the elderly. METHODS AND RESULTS: Twenty three healthy subjects (14 women and 9 men), aged 59 to 82 years (average 68 years), were examined for auditory event-related potentials (AERP) and somatosensory event-related potentials (SERP) using pattern reversal stimulation with large squares (1 degree 10') and small vertical bars (10'). The exogenous components N1 and P2 in both AERP and SERP exhibited significantly longer latencies and higher amplitude in response to target stimuli compared to an indifferent stimulus, a fact attributable to selective attention mechanisms (AERP: N1 delay 8 ms, p < 0.001; P2 delay 11 ms, p < 0.05; increase in amplitude N1/P2 2.2 microV, p < 0.01; SERP: N1 delay 8 ms, p < 0.05; P2 17 ms, p < 0.01; increase in amplitude N1/P2 8 microV, p < 0.001). As for the endogenous components N2 and P3, there were no latency differences between the two modalities (N2: p < 0.4; P3a: p < 02; P3b: p < 0.2). Significant correlations were found between P3 latencies AERP and SERP (r = 0.56, p < 0.01). N1, P2, N2 and P3b latencies of the AERP and P3a, P3b of the SERP correlated significantly with age. The average annual increase was 3.9 ms for P3b AERP (p < 0.01) and 3.2 ms for P3b SERP (p < 0.01). These values are markedly higher than the data reported by other authors for groups of lower average age. In the VEP, an age-related increase was seen in the N70 latency (0.6 ms/year, p < 0.05) and in the P100 latency (0.8 ms/year, p < 0.05) in response to the smaller bars stimulus and in the N140 latency (1.2 ms/year, p < 0.01) in response to the larger squares stimulus. CONCLUSIONS: We confirm an age-related increase in latencies of the AERP and SERP, which is markedly higher than the increase described in other studies with younger subjects. This finding is important to keep in mind in order to avoid false positives of cognitive deficits in older patients. The latencies of later components, compared with earlier components of the VEP, AERP and SERP are more dependent on age. This may suggest that there are universal aging influences on the neuronal conduction velocity. The latencies of the P3b SERP and N2 AERP were found to be correlated with the N140 VEP with the smaller bars stimulus. These findings suggest that parameters of some waves may be modulated by certain other factors than age.

Aged↗
PubMed2002

Long-term ophthalmic outcome of low birth weight children with and without retinopathy of prematurity.

OBJECTIVE: A prospective study of retinopathy of prematurity (ROP) of 505 infants who weighed <1701 g at birth was undertaken in the mid-1980s. This cohort was traced at 10 to 12 years of age to determine how low birth weight alone and ROP might influence their ophthalmic outcome. METHODS: Outcome measures were 1) visual functions (visual acuity, contrast sensitivity, stereoacuity, perimetry, and color vision), 2) presence of strabismus, and 3), measurements of eye size and the dimensions of its components including refractive state. A total of 169 11-year-olds who were born at term were recruited as control subjects and examined under the same conditions. RESULTS: A total of 448 of the original cohort were traced, and 254 consented to a further examination. Compared with the control group, the follow-up cohort differed significantly with reduced visual functions and increased incidence of both myopia and strabismus. Compared with published data, eye size was smaller in the low birth weight cohort. To summarize the ophthalmic data, we defined ophthalmic morbidity as visual acuity below 0.0 log units or the presence of strabismus, myopia, color vision defect, or visual field defect. The rate of ophthalmic morbidity was 50.8% (n = 129/254) in the study cohort compared with 19.5% (n = 33/169) in the control group. The highest rate of ophthalmic morbidity was associated with severe ROP (stages 3/4), although those with no ROP had a less favorable outcome than the control group. CONCLUSION: This study shows that low birth weight children are at increased risk of visual impairments compared with children who are born at full term. Visual impairments are associated with low birth weight per se and severe ROP. Regressed mild ROP is only a risk factor for strabismus. The functional significance of these deficits is largely unknown.

Case-Control Studies↗
PubMed2004

Determinants of patient satisfaction with cataract surgery and length of time on the waiting list.

AIMS: To assess determinants of patient satisfaction with their waiting time (WT) and cataract surgery outcome. METHODS: A prospective cohort of consecutive patients waiting for cataract surgery were assessed by their ophthalmologist. Satisfaction, maximum acceptable waiting time (MAWT), urgency, visual function, visual acuity (VA), and health related quality of life (EQ-5D) were assessed using mailed questionnaires before surgery and 8-10 weeks after surgery. Ordinal logistic regression was used to build explanatory models. RESULTS: 166 patients (61.9% female, mean age 73.4 years) had a mean WT of 16 weeks. Patients whose actual WT was shorter than their MAWT had greater odds of being satisfied with their WT than those whose WT was longer (adjusted OR 3.86, 95% CI 1.38 to 10.74). Improvement in visual function (OR 3.19, 95% CI 1.78 to 5.73), and VA (OR 4.27, 95% CI 1.70 to 10.68) significantly predicted satisfaction with surgery. Models were adjusted for age and sex. CONCLUSION: Patient perspectives on MAWT and satisfaction with WT are important inputs to the process of determining WT standards for levels of patient priority. Patient expectation of WT may mediate satisfaction with actual WT.

Aged↗
PubMedDate not supplied

Assessing the value of laser in situ keratomileusis by patient-reported outcomes using quality of life assessment.

PURPOSE: To assess the value of laser in situ keratomileusis (LASIK) by patient-reported outcomes using quality of life assessment. METHOD: This study included 288 consecutive patients treated by LASIK between July and December 2001 at two eye clinics. A Myopia-specific Quality of Life Questionnaire was developed in this study. The baseline quality of life corresponding to the situation where refractive error was corrected by glasses or contact lenses before LASIK treatment was evaluated by self-administered questionnaire. The evaluation was repeated at 4 days, and 1, 3, and 6 months after LASIK treatment. All question items were rated on a scale ranging from 1 (maximal dysfunction) to 5 (minimal dysfunction). RESULTS: Factor analysis identified 34 questions in 4 subscales-visual function, visual symptoms, social role function, and psychological well-being. The Myopia-specific Quality of Life Questionnaire subscales proved to be internally consistent (Cronbach alpha = 0.70-0.95). Criterion validity was assessed by evaluating Spearman correlation between the overall or domain-specific quality of life and traditional measures of patient status. Overall Myopia-specific Quality of Life Questionnaire score changed from 3.21 preoperatively to 3.76, 4.00, 4.07, and 4.11 at 4 days, and 1, 3, and 6 months after surgery, respectively. Social role function showed the biggest improvement (score change: 1.51, P < .05), followed by psychological well-being (0.90, P < .05), visual function (0.72, P < .05), and visual symptoms (0.49, P < .05). Regression analysis results showed that the degree of uncorrected visual acuity, discomfort associated with myopia preoperatively, and location of eye center were significant factors affecting the magnitude of changes in quality of life after LASIK. CONCLUSIONS: This study confirms that the value of LASIK went beyond the clinical achievement of refractive correction and extended to the improvement of quality of life.

Adolescent↗
PubMed2005

Growth hormone deficiency and memory functioning in adults visualized by functional magnetic resonance imaging.

Cognitive functioning, especially memory performance, is known to be impaired in patients with childhood-onset growth hormone deficiency (CO-GHD), and growth hormone substitution has been found to counteract this memory impairment. Neuropsychological and functional magnetic resonance imagining (fMRI) data acquired during a working memory task in 13 childhood-onset GH-deficient patients were compared with 13 age, sex and education level matched healthy controls. Results demonstrated that there is no difference in the quality of the performance in the working memory task between GH-deficient patients and control subjects. However, memory speed was found to be subnormal in patients. Concerning mood, patients reported more complaints of fatigue, and less vigor. Imaging data showed that patients had increased activity in dorsolateral/ventrolateral prefrontal cortex, anterior cingulate cortex, parietal cortex, supplementary motor and motor cortex, as well as in the thalamus and precuneus area. Increasing task load was also associated with an increase in brain activity in similar areas in patients compared to control subjects. In conclusion, this fMRI study shows that GH-deficient patients have a subnormal memory speed, but no impaired quality of memory performance, which may be due to compensatory recruitment of dorsal prefrontal brain regions. These findings indicate that the GH-IGF-1 axis contributes to prefrontal functioning in patients with CO-GHD.

Adolescent↗
PubMed1987

Are flash-evoked visual potentials useful for intraoperative monitoring of visual pathway function?

Flash-evoked visual potentials (VEPs) recorded from the scalp were used in a series of 35 patients with tumors along the visual pathway: 3 orbital tumors, 25 perisellar tumors, 4 intraventricular tumors, and 3 occipital lesions. Preoperatively, various combinations of impaired visual fields and visual acuity were observed in over 90% of the patients. A postoperative decrease in visual function was observed in 3 cases. Of the 25 perisellar lesions, 13 were operated through a standard frontotemporal craniotomy and 12 were operated through a transnasal-transsphenoidal approach. VEPs were highly susceptible to volatile anesthetics, and there was a significant incidence of spontaneous latency increases and amplitude decreases in a large number of patients. There was an unacceptably high number of cases with significant VEP alteration occurring without concomitant visual function change. During trepanation or the transnasal approach, a reversible potential loss was observed in 11 patients, a profoundly altered wave form was seen in 8 cases, and a loss of single peaks was observed in 15 patients. During dissection of the tumor, a reversible potential loss or a potential with unidentifiable peaks was found in 25 cases; however, the VEPs recovered during closure or in the recovery room. There was no correlation between intraoperative VEP changes and the postoperative changes in visual function. In only 1 patient with an insignificant postoperative decrease in visual acuity from 0.4 to 0.3 was there a concomitant intraoperative potential loss. The major conclusion of our findings is that light-emitting diode flash-evoked VEPs demonstrate intraoperative changes that appear too early and too prominently to be caused solely by manipulation of the optic pathways.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1981

Life-span alterations in visually evoked potentials and inhibitory function.

Visually evoked potentials (VEPs) elicited by patterned and unpatterned flashes were recorded from 211 healthy males aged 4-90 years. A measure of similarity between the two kinds of VEPs was obtained by correlating the digital values comprising the two waveforms. Across the life-span, correlations followed a U-shaped curve; patterned and unpatterned flash VEPs were most alike for the youngest and oldest subjects. This age effect, localized to scalp areas overlying visual cortex, is compatible with a concept of reduced inhibitory functioning within the visual systems of the young and the old. At central scalp, patterned and unpatterned flash VEP waveforms were more effectively differentiated by the right hemisphere. This observation agrees that the right hemisphere specializes in analyses of spatial material.

Adolescent↗
PubMed1995

Evaluation of vestibular and visual oculomotor function.

The visual system interacts synergistically with the vestibular system. A normally functioning vestibulo-ocular reflex is necessary but not sufficient for optimum visual acuity during head motion. Studies of dynamic visual acuity, the acuity achieved during relative motion of visual targets or of the observer, indicate that motion of images on the retina markedly compromises vision. The vestibulo-ocular reflex normally provides a substantial measure of stabilization of the retina during head movements, but purely vestibular compensatory eye movements are not sufficiently precise for optimal vision under all circumstances. Other mechanisms, including visual tracking, motor preprogramming, prediction, and mental set, interact synergistically to optimize the gain (eye velocity divided by head velocity) of compensatory head movements. All of these mechanisms are limited in their capacity to produce effective visual-vestibular interaction at higher rotational frequencies and velocities. It is under these conditions that vestibular deficits give rise to symptoms of oscillopsia. Patients having vestibular lesions exploit mechanisms of visual-vestibular interaction to compensate by substitution for deficient vestibular function. Thus, for accurate topographic clinical diagnosis of vestibular lesions, testing conditions should isolate purely vestibular responses. This may be done by testing reflex eye movements during passively generated rotations in darkness, or perhaps by testing during other types of motion under conditions of extreme frequency and velocity sufficient to attenuate the effects of visual-vestibular interaction. This article reviews clinical tests of vestibular function in relation to synergistic interactions with vision.

Aging↗
PubMed2002

Functional and anatomic outcome of retinal detachment surgery in pseudophakic eyes.

PURPOSE: To determine the long-term anatomic and functional visual outcome of retinal detachment (RD) surgery in pseudophakic eyes after uncomplicated cataract surgery. DESIGN: An interventional, retrospective noncomparative case series PARTICIPANTS: One hundred thirty-eight consecutive patients who had undergone uncomplicated extracapsular cataract extraction and intraocular lens implantation followed by rhegmatogenous RD between 1990 and 1995. METHODS: One hundred one eligible patients were examined (inclusion ratio, 73%) a median of 4.3 years after last RD surgery. The best-corrected visual acuity (BCVA), visual fields, retinal status, and patient-rated visual outcome were recorded, the latter by a questionnaire that included self-reported satisfaction, trouble with vision, a modified Cataract Symptom Score, and the VF-14 Visual Functioning Index. MAIN OUTCOME MEASURES: BCVA, retinal attachment, diameter of visual field, modified Cataract Symptom Score, VF-14 score. RESULTS: Baseline characteristics of enrolled and nonenrolled patients were comparable, except that nonenrolled patients were older. When RD developed, 55 eyes had an intact posterior capsule, and 46 had a laser posterior capsulotomy (LCT). The BCVAs before (median, logarithm of the minimum angle of resolution [-logMAR] 1.2 versus 1.1, Snellen equivalent 0.063 versus 0.08) and after retinal surgery (median, -logMAR 0.46 versus 0.4, Snellen equivalent 0.35 versus 0.4) were comparable for eyes with and without LCT (P = 0.86). The retina was reattached with one procedure in 75 eyes (74%), with two procedures in 98 eyes (97%), and with three to five procedures in all eyes. The retina remained attached long term in 92 eyes (91%). Redetachment rate (9% versus 9%, P = 1.0) and visual field diameters were comparable for eyes with and without LCT. Overall, 80% of patients were satisfied or very satisfied with their binocular vision, and 62% had no or only a little trouble with binocular vision. Visual performance was similar regardless of presence or absence of LCT (median Cataract Symptom Score, 3.0 versus 3.0, P = 0.76; and median VF-14 score, 87.5 versus 87.5, P = 0.81). CONCLUSIONS: Nine in 10 pseudophakic retinal detachments remain attached long term, and 8 in 10 patients are satisfied with their binocular vision after surgery. Even though secondary cataract and posterior capsulotomy can cause problems for the retinal surgeon, the anatomic and functional outcomes of pseudophakic RD are not influenced by capsulotomy.

Adult↗