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PubMed2002

Exploring the perceived world of the deaf-blind: on the development of an instrument.

In the present interview study on a sample of 13 deaf-blind participants (eight Usher patients and five with other diagnoses), all but one with some remaining visual function and all but two with a pure-tone average (PTA) exceeding 100 dB HL, an instrument was developed to assess discovery and localization abilities (DILO), compensatory use of sensory information, emotional and cognitive aspects of communication, and the preferred use of technical aids. Both qualitative and quantitative data were collected, and it was found that (1) the importance of early discovery of events and persons is rated high, (2) vision ranks higher than other sensory information, and airflow, smell and residual hearing come next in the perceptual world of this sample, (3) cognitive aspects of communication correlate with the importance of discovery and localization, and (4) technical aids dominated by vision and vibratory senses are preferred. It is concluded that even a small remaining visual function could be of significant importance in rehabilitation. Finally, in the deaf-blind group of subjects with some remaining visual function, utilization of remaining vision was felt to be more important than utilization of other sensory modalities.

Acoustic Stimulation↗
PubMed1993

Do NMDA receptors have a critical function in visual cortical plasticity?

The theoretical framework, by which we understand the function of NMDA receptors, is derived, in large part, from work conducted on the hippocampal slice preparation, where NMDA receptors are crucial for a form of synaptic plasticity known as long-term potentiation (LTP). Establishing their role in plasticity mechanisms in the neocortex is proving to be far more difficult than originally envisaged, in part due to the fact that the operation of NMDA receptors is different in the intact animal than in vitro. For example, NMDA receptors are activated at low levels of sensory input in intact animals but only by high levels of input in slice preparations. Recent results suggest that a re-evaluation of the role of NMDA receptors in neocortical plasticity is required. Here we discuss some of the issues and introduce four criteria by which any factor supposedly involved in plasticity can be judged. NMDA receptors fulfill more of these criteria than any of the other factors so far investigated in the visual cortex, but maybe this is because they have been studied more intensively.

Animals↗
PubMed2003

Functional imaging of the visual pathways.

Functional neuroimaging has provided a new view of activity in human visual cortex. There have been a series of interesting developments in understanding the relationship between the functional signals, particularly functional MRI, and basic measurements of action potentials and local field potentials. The new human neuro-imaging measurements have clarified some of the similarities and differences between the general organization of visual areas in human and macaque visual cortex, and there have been some interesting new results concerning cortical visual plasticity and dysfunction. The new fMRI focus on measurements of the human brain will drive new relationships between neurology and visual neuroscience that should help us learn much more about the neural basis of perception.

Electroencephalography↗
PubMed1978

Acuity and contrast sensitivity in 1-, 2-, and 3-month-old human infants.

The importance of assessing infant visual function is indicated by recent demonstrations that early visual experience in part determines the eventual state of adult visual function. It is argued that the contrast sensitivity function (CSF) could be a valuable index in the assessment of infant vision because it provides information concerning several aspects of vision. CSF's were measured in 1-, 2-, and 3-month-old infants. The "cut-off" spatial frequencies, which are estimates of visual acuity, were 2.4 cy/deg for 1-month-olds, 2.8 cy/deg for 2-month-olds, and 4.0 cy/deg for 3-month-olds. Sensitivity to contrast was shown to increase between 1 and 3 months of age. The CSF's measured also provide evidence for the presence of a low-frequency fall-off at 2 and 3 months.

Age Factors↗
PubMedDate not supplied

[The use of flavonoid antioxidants in the complex treatment of patients with peripheral vitreo-chorioretinal dystrophies and dystrophic retinal detachment].

Parameters of lipid peroxidation (LP) and antioxidant activity (AOA) of tear and blood plasma were examined in 22 healthy subjects (44 eyes) as well as in 33 patients with peripheral vitreochoreoretinal dystrophies (PVCRD--60 eyes), in 32 patients with non-operated dystrophic retinal detachment (DRD--34 eyes) and in 135 patients with operated retinal detachment, stable visual functions and with the postoperative period ranging from 4 months to 10 years (137 eyes). The results denoted a lower tear AOA (on the average by 35%) in patients with DRD and PVCRD, whereas, the blood plasma AOA or LP products' content remained unchanged. It is indicative of a local nature of metabolic impairments, specifically, of impairments in the system of antioxidant protection of the eye. Flavonoid antioxidants (dikvertin and ginkgo biloba) reduced the content of LP products, and induced the AOA in tear and blood plasma in patients with PVCRD and retinal detachment; they also improved the visual functions in patients with operated retinal detachment. Therefore, the flavonoid antioxidants can be recommended for adding to the complex treatment of PVCRD and DRD for the purpose of improving and stabilizing the visual functions and for neuroprotection.

Administration, Oral↗
PubMed2006

Effects of tenotomy on patients with infantile nystagmus syndrome: foveation improvement over a broadened visual field.

PURPOSE: To investigate the effects of four-muscle tenotomy on visual function and gaze angle in patients with infantile nystagmus syndrome (INS). METHODS: Eye movements of nine patients with infantile nystagmus were recorded using infrared reflection or high-speed digital video techniques. Experimental protocols were designed to record the patients' eye-movement waveforms, pre- and post-tenotomy, at different gaze angles. We used the eXpanded Nystagmus Acuity Function (NAFX) to measure tenotomy-induced changes in the nystagmus at primary position and various gaze angles. The longest foveation domains (LFD) were measured from fitted curves. Peak-to-peak nystagmus amplitudes and foveation-period durations were also measured. All measurements were made unmasked. RESULTS: All seven patients with narrow, high-NAFX, gaze-angle regions showed broadening of these regions of higher visual function. Three patients showed moderate NAFX improvement (13.9-32.6%) at primary position, five showed large improvement (39.9-162.4%), and one showed no NAFX change (due to his high pretenotomy NAFX). Primary position measured acuities improved in six patients. All patients had reductions in nystagmus amplitudes ranging from 14.6 to 37%. The duration of the foveation period increased in all nine patients (11.2-200%). The percentage improvements in both the NAFX and the LFD decreased with higher pretenotomy values. CONCLUSIONS: In addition to elevating primary position NAFX, tenotomy also broadens the high-NAFX regions. This broadening effect is more prominent in patients who had sharp pretenotomy NAFX peaks. Four-muscle tenotomy produces higher primary position NAFX increases in infantile nystagmus patients whose pretenotomy values are relatively low, with the improvement decreasing at higher pretenotomy values. The tenotomy procedure improves visual function beyond primary position acuity. This extends the utility of surgical therapy to several different classes of patients with INS for whom other procedures are contraindicated. The pretenotomy NAFX can now be used to predict both primary position acuity improvements and broadening of a patient's high-NAFX range of gaze angles.

Adolescent↗
PubMed2006

Cognitive impairment in a 65-year-old male with the fragile X-associated tremor-ataxia syndrome (FXTAS).

OBJECTIVE: This is the first case report of a comprehensive neuropsychologic examination of an older man with the fragile X-associated tremor-ataxia syndrome (FXTAS). BACKGROUND: FXTAS, a newly identified phenotype affecting older male carriers of the fragile X premutation allele, is a progressive disorder marked by gait ataxia, action tremor, peripheral neuropathy, executive cognitive deficits, generalized brain atrophy, and neuronal and astrocytic intranuclear inclusion bodies throughout the brain. The patient previously had undergone neurologic evaluation, molecular analysis, and magnetic resonance imaging. METHOD: The patient was administered a neuropsychologic examination, assessing motor and somatosensory functioning, visual and spatial functioning, speech and language, attention, executive abilities, learning and memory, and reasoning. RESULTS: The patient showed a pattern of cognitive impairment characterized by essentially normal speech and language, moderately impaired control of attention, and moderate to severe deficits in working memory, executive functioning, and both declarative and procedural learning. Visual and spatial abilities were relatively unimpaired, and verbal reasoning was only mildly deficient. CONCLUSIONS: The findings suggest that a cognitive disorder, with especially marked executive cognitive function and memory deficits, accompanies FXTAS. The findings in FXTAS are compared with those in several other neurodegenerative disorders.

Aged↗
PubMed2000

Impact of early dietary intake and blood lipid composition of long-chain polyunsaturated fatty acids on later visual development.

BACKGROUND: In contrast to human milk, current infant formulas in the United States do not contain omega3 and omega6 long-chain polyunsaturated fatty acids. This may lead to suboptimal blood lipid fatty acid profiles and to a measurable diminution of visual function in developing term infants. The need for docosahexaenoic acid and arachidonic acid supplementation in the infant diet was evaluated in a double-blind, randomized clinical trial. METHODS: Healthy term infants were randomized to diets of (1) commercial formula, (2) docosahexaenoic acid-enriched formula (0.35% of total fatty acids), or (3) docosahexaenoic acid- (0.36%) and arachidonic acid- (0.72%) enriched formula. Eighty-seven infants completed the 17-week nutritional trial, and 58 were observed until 52 weeks of life. A reference group was exclusively breast fed for at least 17 weeks (n = 29). Outcome measures included electroretinographic responses, visual evoked potentials, and blood fatty acid analysis in infants at birth and at 6, 17, and 52 weeks of age. RESULTS: Commercial formula-fed infants had 30% to 50% lower content of docosahexaenoic acid in total red blood cell lipids during the 17-week feeding trial compared with breastfed infants. Significant differences persisted at the 1-year follow-up. Arachidonic acid content was consistently reduced in the commercial formula group by 15% to 20%. Infants fed long-chain polyunsaturated fatty acid-enriched formulas had docosahexaenoic acid and arachidonic acid blood lipid profiles resembling those of human milk-fed infants. Infants receiving this enriched formula had more mature electroretinographic responses than commercial formula-fed infants at 6 weeks of age. Human milk-fed and docosahexaenoic acid-enriched formula-fed infants had better visual acuity than commercial formula-fed infants at both 17 and 52 weeks of age. Early (17-week) fatty acid profiles in blood lipids were correlated with later (52-week) visual function development in study infants. CONCLUSIONS: Results from this clinical trial demonstrate that long-chain polyunsaturated fatty acid supplementation of formula in term infants produces blood lipid fatty acid profiles that are similar to those observed in breast-fed infants. This supplementation leads to better visual function later in life (i.e., 1 year of age) than that shown by infants fed commercial formula.

Arachidonic Acid↗
PubMed1987

[Significance of the intolerance index in glaucoma].

In 1979 Vodovozov proposed a new individualized index-the intolerance index-for the prognosis of glaucoma. It is calculated as the difference between tonometric and tolerable intraocular pressure, determined after the intake of hypotensive drugs. The lowered tonometric value which coincides with the maximum improvement in visual function (reduced size of the blind spot, enlarged visual field) is considered the individually compatible (tolerable) level of intraocular pressure. The tolerable intraocular pressure and the intolerance index were determined in 379 eyes of 213 patients with open-angle glaucoma; the follow-up period ranged from 18 months to 5 years. Statistical evaluation of the data obtained showed a significant difference between the values for the intolerance index of glaucomatous eyes with stabilized and nonstabilized visual function. In stabilized glaucoma the intolerance index is at most 4 mm Hg. If this is exceeded, one ought to intensify medication or resort to surgery. Lobstein's index (the difference between the mean blood pressure in the central retinal artery and the intraocular pressure) was found to be unreliable in assessing the prognosis.

Acetazolamide↗
PubMed2002

Latanoprost and brimonidine: therapeutic and physiologic assessment before and after oral nonsteroidal anti-inflammatory therapy.

PURPOSE: To assess, before and during oral nonsteroidal anti-inflammatory drug coadministration, latanoprost's and brimonidine's hypotensive action in eyes at risk of glaucomatous progression, assessing the effect of each drug on ocular perfusion and visual function. METHODS: Twenty consenting adults with open-angle glaucoma or ocular hypertension underwent a double-masked, bilateral, randomized prospective study. Treatment started with either latanoprost 0.005% in the morning and placebo in the evening, or brimonidine 0.2% twice daily in one eye; after 1 week starting the other in the fellow eye. After another week, oral indomethacin 25 mg four times a day, commenced for 2 more weeks. Intraocular pressure, ocular circulation, and visual function were monitored pretreatment, after unilateral monotherapy (day 7), bilateral ocular therapy (day 14), and coadministered oral indomethacin (day 28). Intrasubject differences (interocular and intraocular relative to baseline) were determined by two-tailed paired t test. RESULTS: A loss of the significance of intraocular pressure reduction with brimonidine was noted after oral indomethacin coadministration (-14%; P =.004 for brimonidine alone versus -11%; P =.3 with indomethacin). Significant intraocular pressure reduction with latanoprost persisted despite indomethacin (-25%; P <.0001 for latanoprost alone versus -30%; P <.0001 with indomethacin). Pulsatile ocular blood flow increased 40% with latanoprost, but was unchanged with brimonidine (interdrug difference, P =.004). Midperipheral retinal microcirculation increased 23% (P =.03) with latanoprost. Humphrey perimetry and contrast sensitivity remained consistently at or above baseline with both latanoprost and brimonidine. Indomethacin had no significant effect on ocular perfusion or visual function measures. CONCLUSIONS: Circulatory and hydrodynamic findings differed substantially for the two drugs. The loss of significance of intraocular pressure reduction with brimonidine during indomethacin treatment may be clinically important.

Administration, Oral↗
PubMed2006

[Acute retinal necrosis].

AIM: To draw attention to this relatively common disease, which may cause major visual function impairment, and to present our own experience in the diagnosis, treatment and follow-up of acute retinal necrosis patients. METHODS: The manifestation, detection, treatment options and complications of unilateral acute retinal necrosis are illustrated by six case reports. RESULTS: Five patients were immunocompetent, whereas the sixth one suffered from chronic leukemia. In two patients the disease developed in association with herpes zoster, whereas the remaining four showed no signs of herpes disease. Systemic therapy with acyclovir, corticosteroids, salicylates and photocoagulation produced favorable response in five patients. Therapy had to be discontinued in leukemia patient for complications, which resulted in the disease recurrence with retinal detachment and proliferative vitreoretinopathy. Other patients remained stable with preserved visual function and only minor complications. DISCUSSION: In all six patients, the accurate diagnosis was reached relatively late. Obviously, anterior uveitis alone attracted ophthalmologists' attention, and their diagnostic and therapeutic efforts had mostly been focused on anterior uveitis impairment in the visual acuity developed. Appropriate therapy with virostatics, which is necessary in the treatment of this disease, was introduced relatively late, however, all patients responded favorably to this therapy, which also held for the immunocompromised patients administered a half usual dose of acyclovir. Our experience confirmed that virostatic therapy for acute retinal necrosis should be administered for at least 6 weeks. Retinal photocoagulation for prevention of rhegmatogenous retinal detachment appers to be beneficial, as this type of retinal detachment did not develop in these patients. The patient who did not undergo laser photocoagulation of retina did not develop rhegmatogenous retinal detachment but did develop proliferative vitreoretinopathy. CONCLUSION: Acute retinal necrosis is a relatively common disease affecting visual function, which occurs in both immunocompetent and immunocompromised subjects. The disease with its typical clinical picture and many complications should be taken in consideration on the differential diagnosis of uveitis. Therapy for acute retinal necrosis is complex, long-term and associated with frequent systemic complications that may threaten the patient's general health status.

Adult↗
PubMed2005

[Resection of optic nerve sheath meningioma via transcranio-orbital approach].

OBJECTIVE: To investigate the clinical effect of early stage operation for optic nerve sheath meningioma. METHODS: Retrospective study The clinical data of 21 cases of optic nerve sheath meningioma, 6 males and 25 females, aged 39 (12-60), with the chief complaints of loss of vision in 13 eyes (including 6 blind eyes) and proptosis in 8 eyes who underwent resection of the tumors via transcranio-orbital approach were analyzed retrospectively. Radiology showed 15 tumors growing along the optic nerve and enclosing it (flat type), 5 of which showed intracranial invasion; and other 6 of which had the tumors located on one side of optic nerve with spherical shape (nodular type) without intracranial invasion. The patients were followed up for 2-6 years. RESULTS: Total resection was accomplished in 15 cases, and partial removal in 6 cases. Function of oculomotor nerve was preserved in 17 cases, and function of abducent nerve was preserved in 18 cases, visual function was successfully preserved in the 2 cases of small tumor. Tumor recurred in two cases. CONCLUSION: Resection of optic nerve sheath meningioma via transcranio-orbital approach has the advantage of totally removing the tumor and preserving the function of the oculomotor and abducent nerves, preventing tumor from intracranial invasion. Early stage operation is recommended. Visual function may be preserved in the cases of small tumors.

Adolescent↗
PubMed2002

Retinal pigment epithelium translocation after choroidal neovascular membrane removal in age-related macular degeneration.

PURPOSE: To test the feasibility of a new surgical technique and to assess visual function over the translocated retinal pigment epithelium (RPE) cells in patients operated on for subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (ARMD). DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: Nine patients with previously untreated exudative ARMD underwent surgical excision of the subfoveal CNV with RPE translocation and were observed for 12 to 32 months. METHODS: The surgery consisted of a standard three-port pars plana vitrectomy, excision of the CNV, and RPE translocation. Pre- and postoperative ocular examination included best-corrected visual acuity measurement, fundus color stereo photography, and fundus fluorescein angiography. Optical coherence tomography and confocal laser scanning ophthalmoscopy (cLSO) were performed after surgery. A crossfixation target and a single-point flashing light were projected on different areas of the posterior pole using a cLSO. Photopic 10 to 2 perimetry, photopic fine matrix mapping, and cLSO microperimetry were also performed after surgery in six patients. MAIN OUTCOME MEASURES: Optical coherence tomography cross-sectional scans and cLSO RPE autofluorescence were recorded to detect the presence of viable translocated RPE. Visual acuity, fixation, photopic 10 to 2 perimetry, photopic fine matrix mapping, and cLSO microperimetry were used to test central visual function. RESULTS: Retinal pigment epithelium was translocated successfully at the time of CNV removal from the edge of the RPE defect to a subfoveal location in seven of nine patients. One patient experienced proliferative vitreoretinopathy, but significant hemorrhage was not a feature. Optical coherence tomography showed the translocated RPE as an area of increased optical reflectivity with optical shadowing external to it. Confocal laser scanning ophthalmoscopy showed autofluorescence of the translocated RPE. The crossfixation target was seen when projected on the translocated RPE. During eccentric fixation, the patients could see a flashing point-target projected on the translocated RPE. Photopic 10 to 2 perimetry, photopic fine-matrix mapping, and cLSO microperimetry showed the presence of central visual function. CONCLUSIONS: The authors propose that translocation of RPE at the time of CNV removal, from the edge of the RPE defect to a subfoveal location, may have a role in the surgical management of ARMD.

Aged↗
PubMed2005

Towards practical cognitive assessment for detection of early dementia: a 30-minute computerized battery discriminates as well as longer testing.

Early detection of cognitive decline may lead to more effective treatment. Clinical cognitive assessment is essential for early detection, but must be brief with easily interpretable results. The present study defines and evaluates a 30-minute cognitive battery consisting of a subset of tests that comprise a longer computerized battery recently validated in detecting mild cognitive impairment (MCI). Participants were from three tertiary care memory clinics and an assisted living facility (final group: N=161) with consensus diagnoses of cognitively healthy, MCI, or mild dementia. A comprehensive NeuroTrax battery evaluated memory, executive function, visual spatial perception, verbal function, information processing speed, and motor skills. Validity of a single summary measure ('MCI Score') designed for dementia detection and built exclusively from tests of memory, executive function, and visual spatial perception was evaluated with receiver operating characteristic (ROC) analysis. Discriminant validity (area under the curve: AUC) was at least as large for the 6-parameter MCI Score as for a 20-parameter score necessitating administration of the entire battery. Further, the MCI Score had a larger AUC with reduced variance relative to its constituent parameters. AUC for distinguishing dementia was 0.886; AUC for distinguishing cognitively healthy was 0.823. Finally, the MCI Score discriminated among all three diagnostic groups (ANOVA; F[2,150]=52.54, p<0.001). Hence a reduced NeuroTrax battery (30 minutes) with MCI Score is a useful clinical tool for summarizing cognitive data relevant to early dementia detection.

Aged↗
PubMed1988

Patterned dystrophies of the retinal pigment epithelium. A review.

Pigmentations and depigmentations, accompanied or not by yellow subretinal lipofuscin accumulations, are the ophthalmologically visible manifestations of dystrophies of the retinal pigment epithelium. The pigmentations may or may not become confluent and form concentric, butterfly-shaped or reticular configurations. Different patterns of pigment migration may occur in a family and even in one individual. Hence these dystrophies are called pattern(ed) dystrophies of the retinal pigment epithelium. The visual functions are relatively well-preserved, although severe visual impairment is not excluded. The pattern(ed) dystrophies are inherited as an autosomal dominant, an autosomal recessive or an X-linked recessive trait. The author suggests that some cases diagnosed as atypical pigmentary dystrophies with near-normal visual functions probably are dystrophies of the retinal pigment epithelium.

Adolescent↗
PubMed1992

[X-ray computed tomography in surgical indication of physiological section of the optic nerve. Apropos of 15 cases].

Optic nerve trauma induces loss of vision and absence of direct pupillary light reflex. Persistence of consensual pupillary light reflex excludes anatomical section. Trans ethmoidal-sphenoidal decompression relieves the optic nerve and allows an improvement of visual function. Ten patients among 15 surgical decompressions recovered visual function. There is a good correlation between improvement and the release of an anatomical nerve compression. Recognition of direct or indirect computed tomographic signs of optic nerve compression are essential in the surgical indications. The prognosis post-surgical improvement is dependent on the sensitivity of computed tomography scan.

Craniocerebral Trauma↗
PubMed2003

[Retinopathy of prematurity: casuistics between 1996 and 2001].

BACKGROUND: Retinopathy of prematurity (ROP) is a cause of neurosensorial morbidity. OBJECTIVES: To study the incidence, associated risks factors, treatment, and outcome of ROP in premature infants born at less than 32 weeks in our hospital. METHODS: We performed a descriptive study of patients born between the January 1, 1995, and December 31, 2001, in Sant Joan de Déu Hospital in Barcelona (Spain) at <= 32 weeks of gestation who survived until their first month of life. An ocular evaluation was performed between weeks 4 and 6 of life and was repeated every 1-2 weeks until retinal vascularization was complete. Ocular sequelae and visual function were evaluated. Bivariate comparison of groups with and without ROP was performed. RESULTS: Of the 324 patients evaluated, 74 presented ROP (22.8 %), of which 63 patients (21.7 %) were classified as stage 1 or 2 and 11 (3.7 %) as stage 3. An inverse correlation between the incidence of retinopathy and weight and gestational age was found. Threshold disease (3 plus) was detected in 9 patients (16 eyes; 3.1 % of the study sample and 12.1 % of the neonates with retinopathy). All of these neonates were treated with laser therapy. Ocular sequelae were mild in 2.7 % of the patients, moderate in 0.6 % and severe in 0.6 %. The visual function (n 236) of infants with ROP (n 74) was altered in 4 patients (1.7 %). Of these, alterations were severe in 2 patients (0.8 %). Bivariate analysis revealed significant differences (p < 0.001) in low birth weight, gestational age, days of oxygen therapy, days of mechanical ventilation, days of antibiotic therapy, and number of blood transfusions. CONCLUSIONS: In this study the incidence of ROP was similar to that in other centers. Development of ROP was strongly associated with its various risk factors. Severe stages were not seen above 30 weeks of gestational age. The results of laser therapy were optimal, with fewer alterations in ocular examination and visual function than those estimated in patients without treatment.

Blindness↗