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PubMed1992

[The properties of visual functions and familial analysis in blue cone monochromatism].

The diagnosis of blue cone monochromatism (BCM) is based on severely affected color vision with preserved blue function, nearly absent photopic ERG, and a family pedigree compatible with X-linked inheritance. In the past, there has been no familial report of BCM in Japan. We found a Japanese family with BCM and studied the ocular findings of three affected members and a female carrier. Two of three affected members showed unique properties of BCM in their visual functions, including color vision and ERG. One affected member, a brother of their mother (43 years old), showed achromatic color vision. He had diabetic retinopathy and moderate cataract, which, might have disturbed his preserved blue cone function, resulting in the achromatic vision. A female carrier showed normal visual function, except that her photopic ERG was slightly reduced in amplitude.

Adult↗

PubMed1979

Comparison of visual function studies in two cases of senile macular degeneration.

In this paper two relatively early cases of senile macular degeneration are compared by making use of a number of tests of visual function, some relatively new, coupled with observation of the fundus and analysis by fluorescein angiography. The functional tests include visual acuity, the sustainedlike and transientlike functions which are believed to test inner retinal receptive field properties and to have origin in the inner and outer plexiform layers, the Stiles-Crawford function which reflects the directional sensitivity and orientation of photoreceptors, and increment threshold curves. In one case there was evidence of inner retinal involvement at the time the tests were conducted, but, because the Stiles-Crawford function remained essentially normal, it is assumed that the receptors were not disturbed relative to their orientation. In this case (as in many others), the zone or area exhibiting functional change does not necessarily match the area exhibiting anatomical change as observed by examination of the fundus, fundus photography, and fluorescein angiography. In the second patient there is evidence of both anomalous inner retinal function and disturbance in receptor alignment. The later suggests disorientation of the receptor bed. These findings correlated with the fundus observation and fluorescein angiographic evidence of a leak, resulting in the presence of serous fluid beneath the neurosensory retina. With resolution of this fluid there was a return of the functional tests toward normal. At this time, it is not possible to determine whether, in two cases, the functional changes are proceeding on a parallel course, but are at different stages, or whether they are the expression of somewhat different anomalies.

Aged↗

PubMedDate not supplied

Visual functions following bilateral surgery of congenital cataracts in children.

The visual functions, before and after surgery, of 19 children with bilateral congenital cataract are evaluated. Some of the children, in spite of the poor vision before surgery and the late age at surgery, developed good vision with binocular functions. These children probably had an incomplete lens opacity in their early childhood which became completely opaque at an age at which irreversible stimulus deprivation amblyopia is unlikely to develop. Therefore, children over the age of 6 years with poor vision due to congenital cataract, on whom no information is available concerning the density of their lens opacities in early childhood, should not be regarded as having a poor visual prognosis.

Adolescent↗

PubMed1985

Changes in visual functions of children exposed as infants to prolonged illumination.

The visual system can be modified by early experience. Many infants requiring extensive medical treatment spend time in neonatal intensive care units in which they experience prolonged and relatively intense illumination. Visual functions were measured in a group of 7-year-old children who, as infants, were in intensive care for treatment of neonatal jaundice. Using procedures disguised as games, these children were tested for spatial and temporal resolution, receptor functions, and binocular vision. Especially in children whose eyes had not been shielded, deficits were found in color vision, spatial contrast sensitivity, and stereopsis, but not in rod vision.

Child↗

PubMed1985

The California syndrome. Functional visual complaints with potential economic impact.

The records of 84 patients with functional visual loss (59 adults and 25 children) were reviewed over a six-year period. The patients were between 7 and 69 years of age. In the young patients, psychosocial problems relating to parental divorce, poor school performance and attention-getting behavior were common, while in adult patients, financial gain was present in 51 of 59 (86%) individuals. Over 90% of the claimed abnormalities related to the afferent visual system. Fifty-three percent of the patients had underlying organic problems with functional overlay. Inconsistent test results were the most reliable means of identifying the malingering patients. In California, both ophthalmologists and optometrists are able to declare a patient legally blind as well as visually disabled for the purpose of income tax, workers' compensation, and disability benefits. The potential financial impact of malingering patients is discussed.

Adolescent↗

PubMed1986

A comparison of visual function tests in eyes with maculopathy.

Several recently developed tests of visual function, including the Potential Acuity Meter (PAM), laser interferometer (LI), white-light interferometer (WLI), blue field entoptic phenomenon, and focal electroretinogram (ERG) were compared in 81 eyes with clear media and known macular disease. The results indicate that the PAM, the LI, and the WLI overread relative to Snellen acuity. Laser interferometric acuity values differed from Snellen acuity by at least 1.5 octaves in approximately 40% of all eyes, regardless of stimulus size (2, 5, or 8 degrees). Similar results were obtained with the WLI. Agreement with Snellen acuity was better for the PAM, with 91% of eyes falling within 1.5 octaves of Snellen acuity. Blue field and focal ERG results were categorized as normal or abnormal. While not producing Snellen equivalents, abnormal results from the blue field and focal ERG corresponded with poor Snellen acuity (less than 20/40) in 65% and 91% of eyes, respectively. Assuming that media opacities do not prevent adequate retinal stimulation, the present results suggest that the PAM and focal ERG are the most reliable for evaluating macular function when maculopathy is present.

Electroretinography↗

PubMed1987

Visual function, driving safety, and the elderly.

The authors have conducted a survey of the Departments of Motor Vehicles in all 50 states, the District of Columbia, and Puerto Rico requesting information about the visual standards, accidents, and conviction rates for different age groups. In addition, we have reviewed the literature on visual function and traffic safety. Elderly drivers have a greater number of vision problems that affect visual acuity and/or peripheral visual fields. Although the elderly are responsible for a small percentage of the total number of traffic accidents, the types of accidents they are involved in (e.g., failure to yield the right-of-way, intersection collisions, left turns onto crossing streets) may be related to peripheral and central visual field problems. Because age-related changes in performance occur at different rates for various individuals, licensing of the elderly driver should be based on functional abilities rather than age. Based on information currently available, we can make the following recommendations: (1) periodic evaluations of visual acuity and visual fields should be performed every 1 to 2 years in the population over age 65; (2) drivers of any age with multiple accidents or moving violations should have visual acuity and visual fields evaluated; and (3) a system should be developed for physicians to report patients with potentially unsafe visual function. The authors believe that these recommendations may help to reduce the number of traffic accidents that result from peripheral visual field deficits.

Accident Prevention↗

PubMed1986

Visual function in the newborn infant: is it cortically mediated?

Reasonably normal visual behaviour was observed in premature infants in the neonatal period up to about 48 weeks' postmenstrual age even when there was gross destruction of the cortex in the occipital region. Symmetrical visual evoked responses could be elicited at this time even when asymmetrical lesions of the occipital cortex had been demonstrated on ultrasound scan; the visual evoked response became asymmetrical later, around the age of 2 months. A visual evoked response, albeit of abnormal waveform, was recorded in an infant with complete absence of the visual cortex. These findings suggest that early visual function, both behavioural and electrophysiological, is not dependent on the cortex but appears to be mediated through subcortical pathways.

Abnormalities, Multiple↗

PubMed1990

Self-reported visual function and academic success: Cattell revisited.

To test the hypothesis that visual deficits might hamper college students' academic success, we examined the relationship between a reliable self-report measure of visual function and semester grades. The correlation between the Everyday Vision Questionnaire scores and the grades of 331 college students was .01, which replicates and extends the historical findings of Cattell and others.

Achievement↗

PubMed1991

Optic nerve sheath decompression for nonarteritic ischemic optic neuropathy improves multiple visual function measurements.

Optic nerve sheath decompression was performed in seven patients with nonarteritic anterior ischemic optic neuropathy. Visual function was evaluated by measurement of visual acuity with standardized Early Treatment Diabetic Retinopathy Study charts, color vision testing, quantitation of relative afferent pupillary defects with neutral-density filters, and Goldmann and Humphrey perimetry. Visual acuity improved markedly in all patients (at least doubling of the visual angle); the peripheral visual field expanded by at least 20 degrees (as measured by Goldmann perimetry) in six patients. Three patients also experienced marked improvement in color vision, relative afferent pupillary defect, and foveal sensitivity. Our experience supports the possible beneficial effect of optic nerve sheath decompression in patients with nonarteritic anterior ischemic optic neuropathy.

Aged↗

PubMed1977

The effect of corneal edema on visual function.

Corneal edema was produced by atmospheric-induced anoxia and the visual effect was assesed by conventional acuity tests and compared with contrast sensitivity measurements. For the degree of edema which this technique produced, contrast sensitivity was depressed for only high spatial frequencies and could be considered in terms of equivalent defocus. This was not the case ofr a greater degree of edema which was simulated by a diffuser with a particle size that mimics the diffraction effects from an edematous cornea. Equivalent blur was not applicable, since low spatial frequencies were also affected and the letter and contrast sensitivity tests gave radically different results. In the light of these findings, the validity of the present letter acuity evaluation of visual function for patients in which intraocular scattering is involved is questioned.

Cornea↗

PubMed1985

Critical analysis of visual function evaluating techniques in newborn babies.

The most widely-used techniques for testing visual function in babies are reviewed. Advantages and limitations of optokinetic nystagmus testing, visual evoked responses and preferential looking techniques are considered. The theoretical basis and the clinical applicability of those techniques are outlined. Other simple methods are considered as well, which allow practicing ophthalmologists to assess the presence or absence of vision in babies. The importance of early diagnosis for prevention and treatment of visual deficits in babies is stressed.

Evoked Potentials, Visual↗

PubMed1989

Evaluation of the transcranial approach to pituitary adenomas based on quantitative analysis of pre- and postoperative visual function.

Over a 16-year period, 105 patients with pituitary adenoma accompanied by visual disturbance underwent transcranial intracapsular removal of the tumor followed by radiotherapy. Postoperative recovery of visual function in these patients was compared with the results obtained in other institutions after trans-sphenoidal surgery. The severity of preoperative visual impairment was correlated with the duration of visual impairment, the degree of optic atrophy, the extent of suprasellar tumor infiltration, and age. Trans-sphenoidal surgery appears more effective in patients with mild preoperative visual disturbance, whereas the transcranial approach yields better results in patients with moderate to severe preoperative visual deficits.

Adenoma↗

PubMed1992

[An analysis of the causes of glaucomatous visual function damage by computed multifactorial stepwise regression].

Computed multifactorial stepwise regression analysis of quantitative visual field deterioration in relation to 28 factors showed that only the hemorheological indices entered the multiplex regression equations, especially accurately for POAG patients with severe visual damages. Besides, the patients might also have lower antioxidant capability in the red cell membrane protein. Based on the present results and data abroad, POAG might pertain to the blood hyperviscosity syndrome, and with elevated intraocular pressure and decreased ocular arterial pressure, the visual function damage would be aggravated.

Blood Viscosity↗

PubMed1991

Visual function in Alzheimer's disease and normal aging.

We examined a wide range of visual behaviors in 59 patients with Alzheimer's disease (AD), 35 elderly control subjects, and 12 young control subjects. A subset of the patients with AD received neuro-ophthalmologic and electrophysiologic examinations in order to evaluate the integrity of the retino-calcarine pathway. Patients with AD showed significant, selective losses in visual function, including color discrimination, stereoacuity, contrast sensitivity, and backward masking, but not in critical flicker fusion. The deficits were not attributable to clinically apparent lesions of the retina or optic nerve. We therefore suggest that AD lesions in primary visual and posterior association cortices underlie the observed behavioral abnormalities.

Adolescent↗

PubMed1977

The effect of systemic hypotension during cardiopulmonary bypass on intraocular pressure and visual function in humans.

The effect of controlled systemic hypotension on intraocular pressure (IOP) and visual function was measured in a group of 12 patients undergoing extracorporeal perfusion during cardiovascular surgery. When venous pressure was controlled, intraocular pressure was noted to fall following a fall in the systemic blood pressure. There was a return of IOP toward normal levels with recovery of the systemic blood pressure. Systemic hypotension of 25 to 100 mm Hg for up to 201 minutes in the presence of hemodilution and hypothermia was not associated with any functional or morphologic change in ocular function.

Adult↗

PubMed1988

The outcome of visual function in capsular glaucoma.

In a retrospective study is found that 2.5% of subjects aged 70 years or more developed visual field defects due to capsular glaucoma within their lifetime. Before death 0.8% were amaurotic in one eye, and 0.3% had serious impaired visual function caused by bilateral capsular glaucoma. Advanced visual field defects present at diagnosis and central vein occlusion contributed to bad outcome. When glaucomatous disc cupping without visual field defects were present at diagnosis, 50% developed field defects during their lifetime. Of those with moderate visual field defects at diagnosis 59% advanced one or more stages.

Aged↗

PubMed1992

Optic nerve decompression surgery improves visual function in patients with pseudotumor cerebri.

Papilledema from pseudotumor cerebri can cause severe loss of visual acuity and visual field. We performed optic nerve decompression surgery on 17 patients with pseudotumor cerebri who, despite maximum conventional therapy, developed progressive loss of visual acuity and/or visual field. Postoperatively, visual acuity improved or stabilized in 33 of 34 eyes (97%). Visual fields improved in 20 of 21 eyes that underwent surgery. Optic nerve decompression surgery relieves local cerebrospinal fluid pressure on the optic nerve. Progressive loss of visual function associated with pseudotumor cerebri can be reversed or stabilized with optic nerve sheath decompression surgery.

Adolescent↗