Surgical reversal of prolonged blindness from a metastatic neuroblastoma

BACKGROUND: Reports of tumor-related anterior visual pathway blindness that have resolved after surgical decompression are rare. The longest reported duration of tumor-related blindness completely reversed by optic nerve decompression is 3 days. We describe a pediatric patient with 7 days of no light perception who experienced reversal of blindness following tumor resection and optic nerve decompression. CASE DESCRIPTION: A 33-month-old boy presented with a 4-day history of no light perception. Magnetic resonance imaging revealed a mass involving the sphenoid sinus, sella turcica, and clivus with significant optic nerve involvement. Loss of light perception and complete absence of a pupillary light reflex were documented for the next 72 h. A sluggish pupillary light reflex was regained 24 h after instituting intravenous steroids. An urgent bi-frontal craniotomy and optic nerve decompression were performed 7 days after the onset of blindness. Surgical pathology revealed metastatic neuroblastoma. Eleven days after optic nerve decompression, the child was able to count fingers and recognize faces and printed book characters. CONCLUSION: Prolonged blindness secondary to tumor-related optic nerve compression may be reversible up to 1 week from onset in children presenting with no light perception.     

Cortical visual impairment following bacterial meningitis: magnetic resonance imaging and visual evoked potentials findings in two cases

Cortical visual impairment (CVI) following bacterial meningitis is a very uncommon complication. Two children with CVI following bacterial meningits are reported. Bacterial agents wereHaemophilus influenzae type B in one and meningococci in the other child. Both children showed only insufficient recovery from CVI, mental retardation and residual neurological symptoms. Flash visual evoked potentials (VEP) showed preserved cortical response at onset of CVI. Re-evaluations several months later showed significantly reduced amplitudes, but normal latencies for P100. Thus, flash VEP does not allow prediction of visual outcome. MRI results have not been reported before. MRI at onset of diagnosis showed occipital parenchymal irregularities with enlarged sulci and subarachnoid spaces. Follow up MRI15 months after onset of CVI in one patient showed marked atrophy of the occipital cortex, hyperintensities of the cortical white matter and no visible optic radiation. The MRI findings indicate hypoxic-ischaemic lesions in the border zone between the distribution of the great cerebral arteries.     

Perceptual learning in patients with Stargardt disease

ObjectiveTo evaluate the efficacy of Perceptual Learning in improving the peripheral reading performance of patients with Stargardt disease (STGD).DesignProspective observational randomized study.ParticipantsFourteen consecutive patients (7 females, 7 males; median age of 50.4 ± 12.8 years) with STGD were analyzed and divided into two groups: Group A received “Win-flash” as Perceptual Learning training and Group B was used as control.MethodsSubjects underwent an ophthalmic evaluation at baseline, after perceptual learning training and at 6 months of follow-up. Outcomes measured included reading speed, contrast sensitivity and fixation stability.ResultsReading speed improved of 51,7% after training in group A. Visual acuity, contrast sensitivity and fixation stability enhanced in group A after training from 0.89 (±0.09) LogMAR to 0.75 (±0.2) LogMAR (t(6)= 3.6, p= 0.001), from 0.8 (±0.3) LogC (0.6 ? 0.9) to 1.3 (±0.3) LogC (t(13)=3.17, p= 0.003) and from 59.3 % (± 24.3) to 71.5 % (± 20.4) (t(13)=1.8 p= 0.04), respectively. No changes were found in group B. At 6-monts of follow-up, visual acuity and contrast sensitivity decreased in group A.ConclusionsSTGD patients receiving “Win-flash training”, as PL technique, showed an improvement of reading performance on a real-world task. Early follow-up for perceptual learning re-intervention should be considered.     

Recruitment methods for community-based screening for diabetic retinopathy

Regular screening of all people with diabetes is the most efficient and cost-effective way to detect early stages of diabetic retinopathy so that laser treatment can be performed at the optimal time. A major aim of the Program for the Early Detection of Diabetic Retinopathy was to increase compliance with guidelines for screening for diabetic retinopathy. This community-based screening program used non-mydriatic retinal photography and was initiated in four areas of Victoria, Australia from 1996-1998. Recruitment strategies included targeted mail-outs, provision of the program brochure in English and the main languages spoken in the areas and media promotion in ethnic newspapers and on ethnic radio stations. In Victoria, only 55% of the population with diabetes currently access eye care services at the recommended intervals. This program was able to increase compliance with guidelines to 70% among people with diabetes that had not had a recent eye examination. A total of 1,197 people with diabetes were screened for diabetic retinopathy. Of the 1,197 people who were screened, 620 (15% of the estimated number of people with diabetes) had not had their eyes examined in the past two years. This pilot study identified strategies to encourage people with diabetes to have their eyes examined at the recommended intervals.     

Glaucoma de ángulo abierto secundario a cortisona endógena por microadenoma hipofisario en un paciente joven,a propósito de un caso

Case reportA 31-year-old male was referred for evaluation after being diagnosed with Cushing syndrome secondary to a pituitary microadenoma. He presented with a reduced visual acuity and high intraocular pressure (IOP) of 48 mmHg in both eyes. The examination with biomicroscopy showed normal anterior segment, increased cup to disc ratio, and open angle. There was a moderate-advanced involvement in the visual field. The patient was diagnosed with glaucoma secondary to endogenous corticosteroids, and medical treatment was initiated pending the removal of the adenoma. The IOP did not return to normal after the incomplete removal of the adenoma, so a trabeculectomy was performed to control the IOP. As conclusions: In the case of an ocular hypertension with pituitary tumour, secondary glaucoma to endogenous cortisone should be suspected. Early treatment of the tumour is necessary to bring the cortisone and IOP levels back to normal. Late diagnosis or incomplete treatment of these tumours may lead to not obtaining adequate IOP control.     

Derrida,la cécité et les arts du visible. Une perspective philosophique sur les représentations artistiques du handicap

The aim of this paper is to determine what a philosophical approach, the one that Jacques Derrida uses on blindness in his Memoirs of the Blind, can bring to Cultural Disability Studies. Using some of the paintings and drawings reproduced in this 1990 work, the present study first intends to show that, for Derrida, it is a particular way of considering the mutism of visual art works that leads to seeing or imagining, in those that show blind people, representations of blindness that have in common to make it a powerlessness. This paper then analyses how, for the philosopher, these same works can be approached by virtue of a second way of considering their mutism, and thus read as giving rise to the idea of a completely different kind of blindness, understood this time as a power that is highly resistant to the narratives that, in history, have made it an powerlessness. Finally, he proposes to complement this way of reading pictorial images of blindness with Stiker's theorized “Reversal scheme” and the “neo-historicism” applied by Snyder and Mitchell to artistic representations of disability.     

Methanol Poisoning Exposures in the United States: 1993–1998

Objectives: We investigated U.S. methanol-poisoning exposures since little recent information is available about the frequency, sources of methanol, or outcomes of individuals who consume methanol. Methods: We reviewed human methanol exposures reported to the American Association of Poison Control Centers Toxic Exposure Surveillance System 1993–1998. Results: The mean number of cases per year was 2254. Each year 167 cases had an outcome of moderate effect, major effect, or death. One death occurred in every 183 exposures to methanol. Symptomatic cases increased abruptly from 1.8 to 2.5% for infants and children, from 14.1 to 12.3% for adolescents and adults, while the intentional exposures increased from <1 to 21% for adolescents, and 11% for adults. Cases occurred in every decade of life but toddlers had the highest number of exposures. In 68 methanol fatalities, confusion developed followed by coma, hypotension, respiratory depression, and cerebral edema. Blood methanol levels were above 100 mg/dL (70%), metabolic acidoses (62%), and anion gaps >25 (100%). Methanol products were recorded, showing windshield wiper fluids to be 60.8% of exposures. Other automotive sources were 23.7%. Commercial nonautomotive products were 12.2% and pure methanol products were 2.3%. Unintentional exposures were reported in 90.3% of all cases, while 8.3% were due to intentional exposures, and 1.4% was for unknown or mixed reasons. Intentional exposures resulted from suspected suicides (51.2%) and from abuse and misuse (38.8%). Conclusions: Methanol poisonings continue to occur in the United States with toddlers at the highest risk for exposure, but adolescents and adults at the highest risk for life-threatening intoxications. Over half of product-identified cases were due to consumption of windshield wiper fluid. Efforts should be undertaken to minimize methanol exposures.