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PubMed1985

The relationship of endogenous ACTH levels to visual-attentional functioning in patients with congenital adrenal hyperplasia.

The within subject experimental approach of either doubling cortisone medication dose or withdrawing steroid treatment for 36 hr preceding behavioral testing was found to induce corresponding significantly elevated or suppressed plasma ACTH levels, as measured by radioimmunoassay, in six of eight adults diagnosed as having congenital adrenal hyperplasia (CAH). During the session characterized by elevated ACTH levels, the CAH patients exhibited significantly reduced median reaction times on the Sternberg Item Recognition Task. Their response pattern was suggestive of facilitated visual attentional functioning and/or overt motor response capacity rather than alteration of simple cognitive processing. Moreover, Sternberg performance was significantly correlated with endogenous ACTH levels but not with levels of plasma cortisol or cortisone replacement medication. This enhancement of performance paralleled a previous finding of improved performance on the Sternberg paradigm by normal adults following exogenous administration of ACTH 4-10 (Ward et al., 1979). Further analysis of the Sternberg performance suggests that other variables such as mineralocorticoid treatment, type of CAH impairment, and sex may act to moderate the degree of ACTH-related facilitation on this task. Performance on other visual and verbal attention and memory tasks, found earlier to be sensitive indices of exogenous administration of ACTH 4-10 and related fragments, was not significantly altered by manipulation of endogenous ACTH levels in these CAH patients.

Adolescent↗

PubMed1992

Retinocalcarine function in Alzheimer's disease. A clinical and electrophysiological study.

Impaired visual function in Alzheimer's disease (AD) could result from either precortical or cortical lesions, or both. In a parallel psychophysical study of visual function in AD, we found that contrast sensitivity function, color vision, stereoacuity, and backward masking were impaired relative to the performance of age-matched control subjects, whereas performance on a critical flicker fusion test was normal. The intent of the present study was to determine whether abnormalities of the retinocalcarine pathway contribute to visual dysfunction. We performed neuro-ophthalmological examinations on 38 patients with AD; from this group, 25 received additional psychophysical testing and 13 underwent electrophysiological testing. Clinical neuro-ophthalmological examinations, full-field electroretinograms, focal electroretinograms, and pattern visual evoked potentials were normal in all patients tested. There was no evidence of retinocalcarine abnormality specific to AD. We conclude that the visual impairment experienced by some patients with AD primarily results from involvement of the visual association cortices rather than from precortical damage, at least before the end stage of the disease.

Aged↗

PubMedDate not supplied

Visual improvement after removal of submacular exudates in patients with diabetic maculopathy.

OBJECTIVE: To improve the central visual function of eyes affected by massive hard exudates in cases of diabetic maculopathy. PATIENTS AND METHODS: Six eyes of 4 patients with diabetic maculopathy were treated by pars plana vitrectomy for massive retinal exudates persisting for more than 3 months. The massive hard exudates were removed from the subretinal space with subretinal forceps. We evaluated the visual acuity of these eyes 6 months after surgery. RESULTS: Following the removal of the hard exudates, visual acuity improved in all eyes. Massive hard exudates were mainly located in the subretinal space and were removable using subretinal forceps. No serious postoperative complications occurred. The removed tissues consisted of macrophages laden with many cholestrin crystals and lipid droplets, as well as fibrous tissues. CONCLUSION: We concluded that central visual function can be improved by removing subretinal exudates surgically.

Aged↗

PubMed2003

Oral citicoline treatment improves visual pathway function in glaucoma.

BACKGROUND: Increased latency and reduced amplitude of visual evoked potentials (VEP), frequently encountered in ocular hypertension or open-angle glaucoma, suggest slowed neural conduction in the visual pathways. An improvement in VEP latency and amplitude has been reported following repeated intramuscular injections of citicoline, a neuroprotective drug. Our aim was to find whether citicoline given orally would produce a similar effect. MATERIAL/METHODS: VEP latency and amplitude were measured in 21 glaucomatous eyes prior to and after two bi-weekly courses of citicoline taken orally in a dose of 1 gram/day. The treatment courses were separated by a two-week break; post-treatment VEP measurement was performed two weeks after the end of the second treatment. RESULTS: 62% of the eyes showed a response to the treatment, with VEP latency reduced from 123.5 (3.9 SEM) ms to 111.9 (1.9 SEM) ms (P=0.0008), and VEP amplitude increased from 6.56 (1.39 SEM) to 7.88 (1.16 SEM) (P=0.04). CONCLUSIONS: Citicoline given orally improves visual evoked potentials in some glaucoma patients.

Administration, Oral↗

PubMed2006

Is the NEI-VFQ-25 a useful tool in identifying visual impairment in an elderly population?

BACKGROUND: The use of self-report questionnaires to substitute for visual acuity measurement has been limited. We examined the association between visual impairment and self reported visual function in a population sample of older people in the UK. METHODS: Cross sectional study of people aged more than 75 years who initially participated in a trial of health screening. The association between 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ) scores and visual impairment (defined as an acuity of less than 6/18 in the better eye) was examined using logistic regression. RESULTS: Visual acuity and NEI-VFQ scores were obtained from 1807 participants (aged 77 to 101 years, 36% male), from 20 general practices throughout the UK. After adjustment for age, gender, practice and NEI-VFQ sub-scale scores, those complaining of poor vision in general were 4.77 times (95% CI 3.03 to 7.53) more likely to be visually impaired compared to those who did not report difficulty. Self-reported limitations with social functioning and dependency on others due to poor vision were also associated with visual impairment (odds ratios, 2.52, 95% CI 1.55 to 4.11; 1.73, 95% CI 1.05 to 2.86 respectively). Those reporting difficulties with near vision and colour vision were more likely to be visually impaired (odds ratios, 2.32, 95% CI 1.30 to 4.15; 2.25, 95% CI 1.35 to 3.73 respectively). Other NEI-VFQ sub-scale scores were unrelated to measures of acuity. Similar but weaker odds ratios were found with reduced visual acuity (defined as less than 6/12 in the better eye). Although differences in NEI-VFQ scores were small, scores were strongly associated with visual acuity, binocular status, and difference in acuity between eyes. CONCLUSION: NEI-VFQ questions regarding the quality of general vision, social functioning, visual dependency, near vision and colour vision are strongly and independently associated with an objective measure of visual impairment in an elderly population.

Aged↗

PubMed1988

Modified optic nerve sheath decompression provides long-term visual improvement for pseudotumor cerebri.

Twenty-three patients with chronic papilledema associated with pseudotumor cerebri underwent "modified" optic nerve sheath decompression for treatment of visual acuity and visual field loss. Instead of removing a single, rectangular section of optic nerve meninges, the operation was modified by making at least three longitudinal incisions in the sheath and then lysing arachnoid adhesions with a tenotomy hook. Twenty-one of the 23 patients demonstrated improved visual function after the initial surgery for a mean (+/- SD) follow-up of 21.5 +/- 12.3 months (median, 25 months; range, three to 45 months) without reoperation or reinstitution or oral corticosteroid and diuretic therapies. The two patients failing to improve after the first surgical procedure initially had a single meningeal window created and subsequently improved following reoperation with the modified procedure. Twelve of 21 patients with bilateral visual loss had improved visual function bilaterally after unilateral surgery. Six of the 21 patients needed bilateral surgery, and the other three had minor visual field defects in the second eye not severe enough to warrant surgery. Preoperative optic disc pallor did not predict a poor postoperative result. Optic nerve surgery improved the visual function in six patients who had failed to recover vision after one or more lumbar-peritoneal shunts.

Adolescent↗

PubMed1998

Visualization and functional blocking of gap junction hemichannels (connexons) with antibodies against external loop domains in astrocytes.

Astrocytes constitute a metabolically and electrically coupled syncytium which is essential for the regulation of ionic homeostasis of the interstitial brain fluid and for coordinating responses to neuronal activities. The structural avenues that couple individual astrocytes are provided by gap junctions which consist of transmembraneous channels that bridge the extracellular space. Each gap junction channel is composed of two hemichannels (connexons) that dock to each other via their extracellular loops. Here we report on the characterization of external loop antibodies that visualize hemichannels in specific plasma membranes of vital astrocytes. Hemichannels were found to be concentrated on cytoplasmic processes and filopodia of subconfluent cells. Specificity of hemichannel-binding was evaluated by blockage of Lucifer Yellow (LY) dye-transfer and Ca2+ transmission, as well as LY uptake under calcium-deficient conditions. Our data indicate that hemichannels are accessible from the extracytoplasmic side either for direct visualization or functional manipulation. The availability of such a probe will allow in vivo experiments which require selective and/or temporal blocking of gap junctions in animal models.

Animals↗

PubMed2004

Practice-induced changes of brain function during visual attention: a parametric fMRI study at 4 Tesla.

A parametric functional MRI (fMRI) study with three levels of task difficulty was performed to determine the effect of practice and attentional load on brain activation during visual attention tasks. Brief practice during repeat fMRI scanning (20 min) did not change performance accuracy or reaction times (RT), but decreased activation bilaterally in the inferior, middle, and superior frontal gyri, superior temporal gyrus, thalamus, and cerebellum. Increased attentional load decreased performance accuracy but not RT, and increased activation bilaterally in the inferior, posterior, and superior parietal cortices, thalamus, cerebellum, and frontal gyri. These changes suggest that practice decreases dependency on thalamus, cerebellum, and the frontal cortices for controlled task processing possibly due to increased efficiency of the attentional network. Since short-term practice-effects in the prefrontal cortex may be similar to attentional load-effects, studies of attentional load need to take practice effects into account.

Adult↗

PubMed1979

[Visual disorders, functional defects and vitamin deficiencies].

The comparison between complaints, functional defects and vitamin deficiencies is reported for several professional groups characterized by different work conditions. Results suggest that complaints are an useful indicator of visual load and that retinal sensitivity to the light is especially tried. Longitudinal studies are required to verify whether some functional alterations on the aging process of the eye can be aggravated by a visual overload. Visual complaints, functional defects and vitamin deficiencies as indicators of visual load.

Adult↗

PubMed2001

Results of viscocanalostomy for primary open-angle glaucoma.

PURPOSE: Viscocanalostomy is a nonperforating filtering surgical procedure that may avoid postoperative complications common with standard trabeculectomy. This study was conducted to determine the surgical outcome of this procedure after a postoperative observation period of 12 to 36 months. METHODS: Interventional consecutive case series. In a prospective study, a consecutive series of 67 eyes of 67 patients with chronic primary open-angle glaucoma underwent VCS. Excluded were patients with angle closure glaucoma, post-traumatic, uveitic, neovascular, or dysgenetic glaucoma, as well as patients who needed combined cataract-glaucoma procedures. The patients were examined postoperatively on the first day, first week, at 1 month, and then at 3-month intervals through 36 months. At each visit, best-corrected visual acuity, intraocular pressure (IOP), and the appearance of the surgical wound, anterior chamber, and indirect funduscopy were recorded. RESULTS: Complete success was defined as IOP less than or equal to 20 mm Hg and greater than or equal to 30% IOP reduction without medical or additional surgical treatment compared with the IOP from a preoperative level with maximum tolerated medical therapy; qualified success IOP less than or equal to 20 mm Hg with treatment or an IOP reduction less than 30% from preoperative level with maximum tolerated medical therapy; and qualified failure of an IOP greater than 20 mm Hg with glaucoma medication, but no optic nerve or visual field deterioration and complete failure as an eye requiring further glaucoma surgery or lost visual function. The overall success rate was 88% at 1 year, 90% at 2 years, and 88% at 3 years, with a complete success of 68% at 1 year, 60% at 2 and 59% at 3 years. Four eyes had a perforation of the Descemet membrane, three of those needed peripheral iridectomy; six eyes had a microperforation not needing a peripheral iridectomy. Five eyes presented hyphema. Eight eyes presented deterioration of visual function after surgery: three eyes because of corneal astigmatism, one eye because of cataract, and four presented glaucomatous deterioration of the visual field despite pressures under 20 mm Hg. Four eyes had progressive cataract formation judged as independent from surgery. CONCLUSION: VCS provides an overall success rate of 88% and a complete success of 59% 3 years after surgery. The major immediate complication is perforation of the Descemet membrane with a need for peripheral iridectomy. No serious long-term complications were noted in our small series. Visual function remained stable in 55 eyes (82%).

Aged↗

PubMed1996

Eye movement patterns in reading as a function of visual field defects and contrast sensitivity loss.

Saccadic eye movements during reading were examined as a function of the side of visual field cut and the impairment of visual contrast sensitivity Five patients with various visual field defects were compared to five age-matched controls. Patients with right visual field defect showed an increase in the number of rightward saccades and a decrease in their amplitude, and patients with left visual field defects showed a pattern more similar to that of the control subjects. Two patients showed a selective deficit in the range of medium-high spatial frequency; they were the only patients to show a lengthening of mean fixation time during reading. These results indicate selective effects on reading depending on primary sensory defects. The clinical relevance of these findings is briefly discussed.

Adult↗

PubMed2004

Clinical application of the multifocal visual evoked potential.

BACKGROUND: Measures of visual function thresholds such as visual acuity and visual fields are generally dependent on subjective responses and assume maintenance of fixation, attention and motivation. In the young, elderly, cognitively impaired or malingering populations, such measures may be inaccurate or difficult to obtain. The Visual Evoked Response Imaging System (VERIS) has been claimed to give more objective topographic recordings of retinal and cortical function. This paper aims to explore the adequacy of this technique in four unusual, unrelated, clinically difficult cases. METHODS: Multifocal visual evoked potentials (mfVEPs) recorded on the VERIS System 3.01 are used to assess visual function in four cases with contradictory clinical findings or unreliable subjective responses. RESULTS: Patient 1 had sustained a head injury and had normal ocular and pupil examination but light perception in the right eye and 6/5 acuity in the left. Multifocal VEPs showed a marked depression of the right visual field with little macular response. Patient 2 had sustained a head injury, had a left field hemianopia, possible macular sparing and loss of much of the right field, reduced but variable visual acuities, good near vision and normal ocular fundi. Multifocal VEPs showed a severe depression in both visual fields (L more than R) with little macular response. Patient 3 had a left optic nerve meningioma and experienced great difficulty with visual field assessment. mfVEPs showed a bilateral depression in the superior field particularly the left field, with a larger deficit in the left eye. Patient 4 had unexplained visual acuity and peripheral field deficits. mfVEP results were inconclusive in this case. DISCUSSION: Where there is difficulty performing traditional techniques or conflicting clinical findings, mfVEPs may provide additional objective information to aid in the assessment of patients.

Adult↗

PubMed2005

Contrast sensitivity as an outcome measure in patients with subfoveal choroidal neovascularisation due to age-related macular degeneration.

PURPOSE: Although visual acuity is the most frequently used primary outcome measure in clinical trials of treatments for choroidal neovascularisation (CNV) due to age-related macular degeneration (AMD), contrast sensitivity may provide valuable additional information. This paper reviews the evidence for using contrast sensitivity as a measure of visual function and as an outcome measure in clinical trials in patients with subfoveal CNV due to AMD. METHODS: Medline database searches were performed to retrieve relevant articles on contrast sensitivity. In addition, articles were included from the authors' knowledge of the literature and from the reference lists of retrieved articles. RESULTS: The published literature demonstrates that contrast sensitivity is an important measure of visual function in patients with subfoveal CNV due to AMD. Most clinical trials of treatments for CNV due to AMD have reported visual acuity as the primary outcome. However, there is evidence that treatment (such as verteporfin therapy) may also provide additional benefits in terms of contrast sensitivity. These benefits may not be completely characterised by measurement of visual acuity alone. CONCLUSIONS: The inclusion of contrast sensitivity as an outcome measure in studies of patients with CNV due to AMD may provide a more complete understanding of the effects of treatment on visual function and the likely benefits for patients.

Activities of Daily Living↗

PubMed1999

Reduced cerebral blood flow and impaired visual-spatial function in proximal myotonic myopathy.

OBJECTIVE: To compare brain involvement in myotonic dystrophy (DM) with that of proximal myotonic myopathy (PROMM). BACKGROUND: PROMM is a multisystem disease with many features in common with DM. METHODS: Twenty patients with DM (CTGF[500-700), 20 patients with PROMM, and 20 normal control subjects were studied. Neuropsychological testing was performed in 12 patients with PROMM and in 18 patients with DM; brain MRI was performed in 17 of 20 PROMM patients and 15 of 20 DM patients. Ten patients with PROMM and 11 patients with DM were subjected to H2(15)O PET. RESULTS: Two-thirds of the patients with PROMM and one-half of those with DM were impaired on visual-spatial recall, whereas one-third of the patients with PROMM and less than half of those with DM showed an impairment in visual-spatial construction. Brain MRI was normal, or showed only nonspecific white matter abnormalities in both PROMM and DM patients. PET studies in PROMM patients showed a bilateral decrease in regional cerebral blood flow (rCBF) of the orbitofrontal and medial frontal cortex, whereas DM patients had more widespread hypoperfusion that extended to the dorsolateral frontal cortex and subcortical regions. CONCLUSIONS: Impaired visual-spatial function may be present in proximal myotonic myopathy. This correlates best with a reduction in regional cerebral blood flow observed in H2(15)O PET brain scans rather than with specific structural abnormalities observed on brain MRI.

Adolescent↗

PubMed2005

Treatment and vision-related quality of life in the early manifest glaucoma trial.

PURPOSE: To evaluate the effect of treatment, visual function, and other factors on vision-targeted health-related quality of life (HRQOL) of patients with early glaucoma. DESIGN: Randomized clinical trial. PARTICIPANTS: Two hundred fifty-five patients with newly detected open-angle glaucoma and repeatable early visual field (VF) defects, 50 to 80 years old (66% female). METHODS: Patients were randomized to receive either betaxolol plus laser trabeculoplasty in eligible eye(s) or no initial treatment and had ophthalmologic examinations every 3 months. A Swedish translation of the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) was self-administered at 2 follow-up visits (3 and 6 years after randomization). MAIN OUTCOME: Multiple linear regression analyses determined the effect of treatment and other factors on (1) VFQ-25 composite scores at the first administration and (2) change in scores between administrations. RESULTS: Two hundred thirty-three patients had 1 NEI VFQ-25 administration and 167 patients had 2 administrations. Internal consistency reliability was high for the composite VFQ-25 score (Cronbach alpha = 0.88) and satisfactory (alpha> or =0.76) for most subscale scores. At the first administration, the composite score was high (88.8+/-11.7). Mean subscale scores were also generally high (98.0-58.3) and were similar for each study group when analyzed separately. Most lower subscale scores were modestly but significantly related to worse visual acuity (VA) or mean deviation (MD) (better eye, r = 0.15-0.35). Composite scores were similar for treated and untreated patients. Lower composite scores were associated with low VA in the better eye (worse than 0.70) and worse perimetric MD (<4.16 decibels) and nuclear lens opacities (Lens Opacities Classification System II grade > or = 2), but not with age, gender, VF progression, intraocular pressure, cardiovascular disease, or hypertension. Between VFQ-25 administrations, larger decreases in the composite score were associated with larger decreases in VA (P<0.05), female gender (P = 0.001), and older age at first administration (P = 0.006). Treatment (assigned at randomization or later in the study) was not associated with change in HRQOL. CONCLUSIONS: Results suggest that absence or delay of treatment did not influence vision-targeted HRQOL in these newly diagnosed glaucoma patients. However, visual function affected vision-targeted quality of life up to 6 years after Early Manifest Glaucoma Trial enrollment.

Aged↗

PubMed2005

Psychophysical investigation of ganglion cell loss in early glaucoma.

PURPOSE: To evaluate ganglion cell loss in early glaucoma using a variety of psychophysical tests and to identify optimal perimetric technique(s) for detection of early glaucomatous visual function loss. METHODS: Five perimetric tests, short wavelength automated perimetry (SWAP), temporal modulation perimetry (TMP), frequency doubling technology perimetry (FDT), detection acuity perimetry (DAP), and resolution acuity perimetry (RAP) were compared in their ability to discriminate between normal individuals and patients with early glaucoma or glaucoma suspects. Comparisons were also made by their ability to produce repeatable defects. The tests examined different visual functions that are likely to be mediated by different retinal ganglion cell subpopulations, thereby permitting examination of hypotheses of ganglion cell death in early glaucoma. RESULTS: All visual field tests demonstrated high performance in separating glaucoma patients from normal individuals. SWAP, TMP, FDT, and DAP provided the greatest discrimination between normal individuals and high- and low-risk glaucoma suspects. However, SWAP, TMP, and FDT obtained better consistency across the various analysis approaches (global indices and pointwise) than DAP and RAP. Of all the test types, FDT exhibited the highest proportion of repeatable abnormal test locations, with poor confirmation rates achieved by DAP and RAP. CONCLUSION: The performance of SWAP, FDT, and TMP suggests that these test types may all be suitable for detection of early loss of visual function in glaucoma. Ganglion cell subpopulations with lower levels of redundancy and/or those with larger cell sizes offer the most parsimonious explanation for earliest ganglion cell losses occurring in glaucoma.

Cell Death↗

PubMedDate not supplied

[The use of the helium-neon laser in the treatment of amblyopia in children].

The authors analyze the efficacy of He-Ne laser therapy of amblyopia of various origins in 48 children (81 eyes). Group 1 children were not treated at all in order to assess the visual function background fluctuations (absolute controls). Along with He-Ne laser, used in Group 2, a 'placebo', slit lamp with blinking light, was used in Group 3. Vision acuity was assessed with the use of Sivtsev-Golovin's and Orlova's tables and by visocontrastometry in a blind test. Common visometry has shown a reliable and approximately similar improvement of the vision acuity in Groups 2 and 3 patients, whereas visocontrastometry has not detected any changes of visual function in all the 3 groups. These results cast doubt on the true efficacy of He-Ne laser stimulation of visual function, at least in children, and once again demonstrate that such investigations may be carried out only with a reliable ('blind') control and placebo.

Adolescent↗

PubMed2002

[Foveal cone dystrophy: diagnostic ranking of the multifocal electroretinogram].

BACKGROUND: In case of visual loss without morphologic pathology differentiation between a functional visual loss and a retinal disorder may be difficult. PATIENTS AND METHODS: We report on two women, aged 33 and 44, who were complaining of a progressive visual loss occurring over the past several weeks to months. They were referred to our department with the presumed diagnosis of functional visual loss. Biomicroscopy of the anterior and posterior segments, perimetry (Goldmann), colour (FM-100-Hue-Test) and stereopsis testing (Lang-Stereotest), fluorescein angiography (FLAG) and electrophysiological testing (P-ERG, VECP, EOG, multifocal electroretinography [mfERG]) were performed. RESULTS: Visual acuity was 0.16 OU and 0.25 OU respectively. A small relative central scotoma (I/1) was detected by dynamic perimetry. Colour vision, random-dot stereopsis and the results of electrophysiological testing except multifocal electroretinography (mfERG) were normal. The mfERG was able to detect a cone dysfunction which was related to the fovea. CONCLUSION: In case of visual loss of unknown etiology electrophysiological testing is indicated. The mfERG as an objective diagnostic method is able to detect a foveal cone dystrophy.

Adult↗