Prevalence and clinical features of migraine in a population of visually impaired subjects in Curitiba, Brazil.

To investigate the relevance of lacking or diminished visual input on the expression of migraine, we evaluated its prevalence and clinical features in a population of visually impaired subjects. Between September 1999 and April 2000, 203 visually impaired subjects with a headache inventory were surveyed. Those with headache were assessed according to IHS criteria for the presence of migraine. Migraineurs had their symptoms further detailed through an interview and a headache diary. Of the 104 subjects reporting headaches during the last 6 months, 29 had migraine (14.2%). The prevalence of migraine was not influenced by whether the visual impairment was complete or partial. Mean frequency of migraine attacks was 2.7/month. Most subjects (96%) reported severe and/or moderate attacks. Nausea, vomiting, aggravation by activity and phonophobia were reported by 62%, 37.9%, 86.2% and 96.6% of the subjects, respectively. Visual impairment does not seem to influence prevalence of migraine or its clinical features.

A new betaA1-crystallin splice junction mutation in autosomal dominant cataract.

PURPOSE: To map the locus for autosomal dominant cataracts (ADCs) in a Brazilian family using candidate gene linkage analyses, describe the clinical variability, and identify potential mutations in the human betaA1-crystallin gene (CRYBA1), a candidate gene identified through linkage studies demonstrating cosegregation with markers on chromosome 17. METHODS: Members of a Brazilian family with ADC were studied. Clinical examinations and linkage analyses with polymerase chain reaction (PCR) polymorphisms of 22 anonymous markers and 2 within the neurofibromatosis type 1 gene were performed; two-point lod scores were calculated. DNA sequences of all 6 exons and 12 exon-intron boundaries of the betaA1-crystallin gene, a proximal candidate gene mapped to 17q11.1-q12 in one unaffected and two affected individuals, were screened and new variants assessed for cosegregation with the disease. RESULTS: Affected individuals exhibited variable expressivity of pulverulent opacities in the embryonal nucleus and sutures; star-shaped, shieldlike, or radial opacities in the posterior embryonal nucleus; and/or midcortical opacities. All known loci for ADC in this family on chromosomes 1 and 13 were excluded. A positive lod score on chromosome 17 was calculated. This ADC locus was mapped to two potential regions on the long arm with an intervening recombination. The only known candidate gene in these regions was betaA1-crystallin. Three previously unreported single nucleotide variants were found in this gene, one in the donor splice junction site of intron C. This variant was found in all affected members and is presumed to be the causative mutation. CONCLUSIONS: An ADC locus was mapped in a Brazilian family with variable expressivity to either 17q23.1-23.2 or 17q11.1-12 based on linkage analyses. Analyses of DNA sequences of the betaA1-crystallin gene in this family revealed three new variants, one of which is within a donor splice junction and cosegregates with affected members.

Experimental studies with perfluoro-octane for hemostasis during vitreoretinal surgery.

PURPOSE: To investigate the effect of perfluoro-octane on coagulation studies and on intraoperative hemostasis during vitreoretinal surgery in an animal model. METHODS: In vitro study--comparison of coagulation profiles (bleeding time, whole blood clotting time, partial thromboplastin time, and one-stage prothrombin time) of blood taken from healthy volunteers with and without the addition of perfluoro-octane. In vivo study--comparison of times taken to achieve hemostasis in a rabbit model with large retinal arterial bleeding in vitrectomized and aphakic eyes with and without intraocular injection of perfluoro-octane. RESULTS: In vitro study--perfluoro-octane had no significant effect on coagulation profiles. In vivo study--intraocular perfluoro-octane significantly reduced the time to achieve hemostasis (P < 0.01) at all infusion bottle heights in vitrectomized and aphakic rabbit eyes. CONCLUSIONS: Perfluoro-octane may be used to control bleeding during vitreoretinal surgery. A direct effect on the clotting cascade could not be demonstrated.

In vitro and in vivo studies with sodium hyaluronate as a carrier for intraocular gentamicin.

We compared the in vitro growth of common intraocular pathogens Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa in rabbit vitreous and in sodium hyaluronate (SH) with and without gentamicin. The minimal inhibitory concentration for gentamicin/SH was 0.5, 0.062 and 2.0 mcg/ml for these pathogens, respectively. After posterior capsulotomy, P. aeruginosa was inoculated into the anterior vitreous and all 15 untreated eyes developed endophthalmitis. In a similar group, aqueous gentamicin administered in the anterior chamber reduced the incidence of endophthalmitis to 10 of 15 eyes. Under similar circumstances, the SH/gentamicin combination lowered the incidence of endophthalmitis significantly to 4 of 15 eyes. The half-life of aqueous gentamicin was 0.9 h, which was shorter than the 2.2 h for SH/gentamicin combination. These results suggest that SH may be a useful carrier for intraocular drug therapy.

Sodium hyaluronate as a carrier for intravitreal gentamicin. An experimental study.

Fifty mcg of gentamicin was combined with saline or with 0.8% sodium hyaluronate and injected into the vitreous cavity of rabbit eyes with moderate to severe Staphylococcus aureus endophthalmitis. Endophthalmitis was controlled in 9 of 10 eyes. There was no evidence of toxicity with either treatment regimen. Although the clearance study demonstrated statistical differences at all time points studied, the half-lives of both treatment regimens were similar (3.3 h for aqueous gentamicin and 3.6 h for sodium hyaluronate/gentamicin). These results suggest that the vitreous played a role in keeping the aqueous gentamicin in the eye for a longer time, as similar half-lives were shown with both types of treatment. Thus, if a vitrectomy has to be done for the treatment of endophthalmitis, as much as possible of the vitreous should be left in situ to maintain the drug for longer periods in the eye. Also, if it is necessary to remove all vitreous during vitrectomy, it may be more effective to administer the drug with sodium hyaluronate so as to prolong its action inside the eye.