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At least 1,009 records · Page 56Linked to original sources
PubMed1995

Visual function in patients with optic neuritis associated with acute transverse myelopathy in multiple sclerosis.

The authors reviewed the records of 20 patients with optic neuritis, all of whom were diagnosed as having clinically definite multiple sclerosis (MS). They were classified into two subgroups: Group A, consisting of 9 patients who had shown acute transverse myelopathy (ATM); and Group B, 11 patients without ATM. Four patients (44%) in Group A had complete visual loss, but none in Group B. Six patients (67%) in Group A had less than 0.1 visual acuity in the affected eye, but only 2 patients (18%) in Group B. Four patients in Group A showed evidence of anticardiolipin antibodies. While both groups were diagnosed as having clinically definite MS, there were differences between them in the clinical features. We assume that the patients with ATM may constitute a different subgroup among MS patients.

Acute Disease↗
PubMed1995

Clinical comparison of three techniques for evaluating visual function behind cataract.

The aim of the study was to compare the ability of displacement threshold hyperacuity to identify reduced retinal/neural function in cataract patients with that of the potential acuity meter (PAM) and laser interferometer. Fifty-two patients (mean age 72.0 +/- 10.8 years) admitted for extracapsular cataract extraction were randomly selected for inclusion in the study. Patients underwent routine refraction and logMAR acuity measurement on the eve of cataract surgery. Following pupillary dilation and in random order, the oscillatory displacement threshold (ODT; defined as the smallest detectable displacement of an object) was determined, and predictions of the post-operative acuity were obtained using the PAM and Rodenstock Retinometer (RR). Patients were re-examined approximately 7 weeks post-operatively when logMAR acuities and ODTs were remeasured. On the basis of the results of an independent fundus examination, patients were assigned to either a normal or a pathology group. Increasing cataract density adversely affected the predictions provided by the PAM (p = 0.0001) and ODT (p = 0.0001) techniques, but not the RR (p = 0.137). One-factor ANOVA revealed that pre-operative ODT (p = 0.0001), PAM (p = 0.0001) and RR (p = 0.0004) measures successfully distinguished patients with retinal/neural pathology from normals. Pre-operative cut-off levels to distinguish normal from pathology cases were retrospectively determined for each technique. The cut-off values for the PAM and ODT techniques yielded higher sensitivity and specificity values than was the case for the RR. The results suggest that the predictive abilities of the PAM and ODT techniques are similar, and superior to that of the RR. Further work involving larger numbers of patients with posterior segment pathology is necessary to reveal which technique provides the best means of assessing retinal/neural function in the presence of ocular media opacities.

Aged↗
PubMed2004

Age-related changes in the functional visual field: further evidence for an inverse Age x Eccentricity effect.

We assessed the performance of younger and older individuals by using the Attended Field of View test, a visual search task in which eye movements were allowed. When adjusting for slower processing in the older age group by log transformation, we observed significant effects of age, eccentricity, and Age x Eccentricity. Contrary to most previous findings, the Age x Eccentricity effect was "inverted" in that the difference between the age groups decreased as a function of eccentricity. The finding that the eccentricity effect of younger individuals was larger than that of older individuals was caused by large age-related differences in sensitivity for centrally located targets, even though differences with regard to foveal resolution were controlled. The results further indicated that, given a brief amount of time, older persons could process a smaller field of view than younger persons. Consequently, older persons were forced to resort to serial scanning for a larger part of the display, whereas younger persons could process a larger area in parallel.

Adult↗
PubMed1996

Pre-term delivery and subsequent ocular development. A 7-10 year follow-up of children screened 1982-84 for ROP. 1) Visual function, slit-lamp findings, and fundus appearance.

An ophthalmic follow-up comprised 88 children aged 7-10 years who had regular screening for retinopathy of prematurity (ROP) after their pre-term delivery 1982-84. Mean values of birth weight and gestational age in the 88 were 1467 g and 31 weeks. Out of 28 with early evidence of ROP four had progressed to bilateral blindness; the remaining 24 had at least a corrected visual acuity of 0.4 at disposal. The corrected median binocular acuity for all 88 was 0.95; however, the cumulated frequency curve was significantly below a previously stated norm in full-terms. The same conclusion was valid for single eye vision. Within the material, the visual score of the 28 with early ROP was significantly lower than in the remaining 60 subjects. Ophthalmoscopy often showed tortuosity of vessels, but no specific central retinal or optic nerve lesion to explain the slight general depression of visual acuity, and opacities of media contributed in only two subjects. It is concluded, that very preterm delivery generally influences the potential for developing full visual acuity, also in individuals without evidence of early ROP. Evidence of CNS-damage negatively influenced visual acuity score.

Accommodation, Ocular↗
PubMed2001

[Visual function in myopia 2 years after photorefractive keratectomy].

1. 86 myopes undergoing photorefractive keratectomy (PRK) with refraction from -0.25 D to -12.00 D were divided into 4 groups: A: up to -2.75 D, B: -3.00 D to -5.75 D, C: -6.00 D to -8.75 D and D: -9.00 D to -12.00 D. 20 emmetropes of the same median age were evaluated as a control group. The patients were examined 2 years after PRK. 2. Best corrected visual acuity (BCVA) increased in groups A, C, D and decreased in group B compared to values one year after PRK. Both changes were only nonsignificant. 3. Contrast sensitivity (CS) was equal to values one year after PRK in group A, the same was true for groups C and D with exception of lower values in the highest spatial frequency. In group B, CS decreased significantly compared to values one year after PRK. 4. In groups A, B a C number of patients without rest correction increased, regression was seen only in group B. 5. BCVA changed only nonsignificantly under glare of 41.1 cd/m2, 342.6 cd/m2 and 1360.4 cd/m2 in 97% of patients.

Adolescent↗
PubMedDate not supplied

Near-UV/blue light-induced fluorescence in the human lens: potential interference with visual function.

Irradiation of the ocular lens of numerous species by near-UV or short-visible wavelengths induces a blue-green fluorescence, which can be a source of intraocular veiling glare. Wavelengths longer than the approximately 365-nm lens absorption peak induce progressively weaker but also progressively more red-shifted fluorescence emission. The more red-shifted emission has a higher luminous efficiency and, in fact, earlier studies in this laboratory have demonstrated that the lens fluorescence in the nonhuman primate yields an approximately constant luminous efficiency when excited by equal radiant exposures over the wavelength range from 350 to 430 nm. Now, with the recent development and projected widespread use of "blue" diode lasers, a further study extending the measurements of the induced fluorescence efficiency and of the consequent veiling glare to the human lens seemed timely. The current study quantifies the fluorescence intensity induced in the human lens, both in terms of radiance and luminance, as a function of exciting light intensity, excitation wavelength, and subject age. The spatial distribution of the emitted fluorescence is also examined. These data are shown to imply that exposure to near-UV/blue wavelength sources at "safe" exposure levels (according to existing laser safety standards) can induce a veiling glare intense enough to degrade visual performance, and that the fluorescence intensity and consequent glare disruption show little dependence on subject age.

Adult↗
PubMed2001

Retinal dystrophies caused by mutations in RPE65: assessment of visual functions.

AIMS: To characterise the disease in patients with mutations in RPE65. METHODS: Individuals from two families were studied clinically. RESULTS: 13 and 20 year old compound heterozygote individuals from one family with R234X and 1121delA mutations showed nystagmus, macular dystrophy and low contrasted spots in the fundus. Some heterozygotes had macular drusen. A 40 year old compound heterozygote individual from another family with L22P and H68Y mutations had few bone spicule pigment deposits and macular atrophy. CONCLUSION: Compound heterozygote individuals had severe rod-cone dystrophies featuring few pigment deposits in the fundus, pigment epithelium atrophy, and early involvement of the macula, with variations in severity leading to the diagnosis of Leber's congenital amaurosis or retinitis pigmentosa. Macular drusen in heterozygotes carrying a null allele may reflect the decreased capacity in the RPE65 function.

Adolescent↗
PubMed2005

Dietary lutein and zeaxanthin: possible effects on visual function.

Of the many carotenoids circulating in human sera, only lutein and zeaxanthin are accumulated throughout the tissues of the eye. Within the eye, they reach their highest concentration in the central retina, where they are clinically referred to as the macula lutea. Lutein and zeaxanthin, more commonly referred to as macular pigments, may serve a variety of roles in the specialized vision of higher primates. This paper reviews recent studies investigating the influence of macular pigments on human visual performance. Such studies have offered insight into why lutein and zeaxanthin are uniquely concentrated in ocular tissues.

Antioxidants↗
PubMed1964

VISUAL FUNCTION OF THE FOREBRAIN COMMISSURES IN THE CHIMPANZEE.

Interocular transfer of learned pattern discrimination tasks in chimpanzees with sectioned optic chiasma is dependent on the forebrain commissures. This function is sustained by the splenium and the anterior commissure, the former pathway being the more capable.

Animals↗
PubMed2003

Visual function in breast-fed term infants weaned to formula with or without long-chain polyunsaturates at 4 to 6 months: a randomized clinical trial.

OBJECTIVE: Breast-fed infants receive docosahexaenoic acid (DHA) and arachidonic acid (ARA) in their diet. Upon weaning, infants lose this dietary source of long-chain polyunsaturates because many commercial formulas do not contain these important constituents for neural membrane biogenesis. We evaluated the benefits of postweaning dietary supplementation of DHA + ARA on visual maturation. STUDY DESIGN: Healthy term infants (n = 61) were breast-fed to 4 to 6 months, then were randomly assigned to commercial formula or formula supplemented with DHA (0.36%) + ARA (0.72%). Measurements of red blood cell (RBC) fatty acids, visually evoked potential (VEP) acuity, and stereoacuity were done before and after weaning. RESULTS: At 1 year of age, RBC-DHA in the commercial formula-fed group was reduced by 50% from the weaning level, whereas there was a 24% increase in the DHA + ARA-supplemented group. The primary outcome measure, VEP acuity, was significantly more mature in supplemented infants at 1 year of age. Elevated RBC-DHA levels were associated with more mature VEP acuity. There were no significant diet-related differences in stereoacuity. CONCLUSIONS: These data extend through the first year of life the critical period in which a dietary supply of DHA and ARA can contribute in optimizing visual development in term infants.

Arachidonic Acid↗
PubMedDate not supplied

[Effects of trans-scleral laser cyclo-coagulation on intraocular pressure and visual function in patients with far advanced open-angle glaucoma].

Transscleral diode laser cyclocoagulation was modified so that laser coagulants (20-25 applications) were applied not only to the ciliary crown, but to the flat part of the ciliary body as well. Inflammation modulators forming after coagulation thus enter aqueous humor and the vitreous body and penetrate into the retina and optic disc, causing dilatation of capillaries and stimulating the blood stream in them. Forty patients (40 eyes) with far advanced glaucoma and pronounced concentrical narrowing of the visual field were operated on and observed for 6-12 months postoperation. One month after the intervention intraocular pressure decreased by 9-21 mm Hg and was below 22 mm Hg in 38 eyes; visual acuity increased by 0.1-0.3 in 11 cases; visual field widened in all patients. These results did not appreciably change till the end of the period of observation.

Aged↗
PubMed1992

Inferotemporal cortex and higher visual functions.

Recent studies have led to a better understanding of the mechanisms of object vision in the inferotemporal cortex. In particular, a columnar organization has been revealed, and a short-term change of responsiveness has been proposed as a neural correlate of working memory.

Animals↗