[Eye care services evaluation in a low-income urban population of São Paulo City--Brazil].

Purpose: To evaluate eye care services from the user's perspective in a low income population from the east zone of the city of São Paulo--Brazil.

Methods: A household survey was performed using cluster sampling in three low income districts of the city of São Paulo--Brazil. From July/2004 to January/2005, 1055 interviews with an adult household representative were carried and an eye care system responsiveness questionnaire was administered through individual interview.

Prevalence and causes of visual impairment in low-middle income school children in Sao Paulo, Brazil.

Purpose: Assess prevalence and causes of vision impairment among low-middle income school children in São Paulo.

Methods: Cluster sampling was used to obtain a random sample of children ages 11 to 14 years from public schools (grades 5-8) in three districts from June to November 2005. The examination included visual acuity testing, ocular motility, and examination of the external eye, anterior segment, and media.

Prevalence and causes of vision impairment and blindness in older adults in Brazil: the Sao Paulo Eye Study.

Purpose: Investigate prevalence and causes of vision impairment/blindness in older adults in a low-middle income area of Sao Paulo, Brazil.

Methods: Cluster sampling, based on geographically defined census sectors, was used in randomly selecting cross-sectionally persons 50 years of age or older. Subjects were enumerated through a door-to-door survey and invited for measurement of presenting and best-corrected visual acuity and an ocular examination.

Haplogroup effects and recombination of mitochondrial DNA: novel clues from the analysis of Leber hereditary optic neuropathy pedigrees.

The mitochondrial DNA (mtDNA) of 87 index cases with Leber hereditary optic neuropathy (LHON) sequentially diagnosed in Italy, including an extremely large Brazilian family of Italian maternal ancestry, was evaluated in detail. Only seven pairs and three triplets of identical haplotypes were observed, attesting that the large majority of the LHON mutations were due to independent mutational events. Assignment of the mutational events into haplogroups confirmed that J1 and J2 play a role in LHON expression but narrowed the association to the subclades J1c and J2b, thus suggesting that two specific combinations of amino acid changes in the cytochrome b are the cause of the mtDNA background effect and that this may occur at the level of the supercomplex formed by respiratory-chain complexes I and III.

[Visual acuity and full-field electroretinography in patients with Usher's syndrome].

Purpose: Usher's syndrome (US) is a group of genetically distinct autosomal conditions, characterized by sensorineural hearing loss accompanied by a retinal dystrophy indistinguishable from retinitis pigmentosa (RP). The purpose of this study was to analyze full-field electroretinography (ERG) and visual acuity (VA) among patients with type I and II Usher's syndrome.

Methods: Electroretinography responses and visual acuity were studied in 22 patients (mean age at test = 26.