Visual impairment in children with spastic cerebral palsy measured by psychophysical and electrophysiological grating acuity tests

Background: This study measured grating visual acuity in 173 children between 6-48 months of age who had different types of spastic cerebral palsy (CP). Method: Behavioural acuity was measured with the Teller Acuity Cards (TAC) using a staircase psychophysical procedure. Electrophysiological visual acuity was estimated using the sweep VEP (sVEP). Results: The percentage of children outside the superior tolerance limits was 44 of 63 (69%) and 50 of 55 (91%) of tetraplegic, 36 of 56 (64%) and 42 of 53 (79%) of diplegic, 10 of 48 (21%) and 12 of 40 (30%) of hemiplegic for sVEP and TAC, respectively. For the sVEP, the greater visual acuity deficit found in the tetraplegic group was significantly different from that of the hemiplegic group (p < 0.001). In the TAC procedure the mean visual acuity deficits of the tetraplegic and diplegic groups were significantly different from that of hemiplegic group (p < 0.001). The differences between sVEP and TAC means of visual acuity difference were statistically significant for the tetraplegic (p < 0.001), diplegic (p < 0.001), and hemiplegic group (p = 0.004). Discussion: Better visual acuities were obtained in both procedures for hemiplegic children compared to diplegic or tetraplegic. Tetraplegic and diplegic children showed greater discrepancies between the TAC and sVEP results. Inter-ocular acuity difference was more frequent in sVEP measurements. Conclusions: Electrophysiologically measured visual acuity is better than behavioural visual acuity in children with CP.

Impacto do déficit visual na qualidade de vida em idosos usuários do sistema único de saúde vivendo no sertão de Pernambuco

OBJETIVO: Avaliar o impacto das doenças oculares sobre a qualidade de vida de uma população idosa do sertão de Pernambuco, localizado na região nordeste do Brasil. MÉTODOS: Foram entrevistados 580 indivíduos acima de 59 anos, por meio do questionário de avaliação de qualidade de vida "Visual Functioning Questionnaire" (VFQ). Todos os indivíduos foram submetidos a exame oftalmológico completo. Os resultados das variáveis quantitativas foram expressos por suas médias e desvios- padrão. Os resultados das variáveis qualitativas foram expressos por suas frequências absolutas e relativas. RESULTADOS: A média de idade foi de 70 ± 8,1 anos. Cerca de 86,0% dos entrevistados declararam ser analfabetos ou ter o ensino fundamental incompleto. As principais queixas foram: baixa visual (71,1%) e ardor/prurido (69,0%). A acuidade visual não era normal em 37,4% dos idosos. Por volta de 75,0% dos entrevistados relataram ter saúde regular ou ruim, e 77,0% diziam ter uma visão regular ou ruim. A qualidade de vida foi considerada pior conforme a piora da condição visual do idoso. CONCLUSÃO: O déficit visual representou um impacto negativo sobre a qualidade de vida dos idosos do sertão Pernambucano.

Contrast Sensitivity Mediated by Inferred Magno- and Parvocellular Pathways in Type 2 Diabetics with and without Nonproliferative Retinopathy

PURPOSE. To evaluate achromatic contrast sensitivity (CS) with magnocellular-(M) and parvocellular-(P) probing stimuli in type 2 diabetics, with (DR) or without (NDR) nonproliferative retinopathy. METHODS. Inferred M-and P-dominated responses were assessed with a modified version of the steady-/pulsed-pedestal paradigm (SP/PP) applied in 26 NDR (11 male; mean age, 55 +/- 9 years; disease duration, 5 +/- 4 years); 19 DR (6 male; mean age, 58 +/- 7 years; disease duration = 9 +/- 6 years); and 18 controls (CTRL; 12 male; mean age, 55 +/- 10 years). Thresholds were measured with pedestals at 7, 12, and 19 cd/m(2), and increment durations of 17 and 133 ms. The thresholds from the two stimulus durations were used to estimate critical durations (Tc) for each data set. RESULTS. Both DR and NDR patients had significant reduction in CS in both SP and PP paradigms in relation to CTRL (Kruskal-Wallis, P < 0.01). Patients` critical duration estimates for either paradigm were not significantly different from CTRL. CONCLUSIONS. The significant reduction of CS in both paradigms is consistent with losses of CS in both M and P pathways. The CS losses were not accompanied by losses in temporal processing speed in either diabetic group. Significant CS loss in the group without retinopathy reinforces the notion that neural changes associated with the cellular and functional visual loss may play an important role in the etiology of diabetic visual impairment. In addition, the results show that the SP/PP paradigm provides an additional tool for detection and characterization of the early functional damage due to diabetes. (Invest Ophthalmol Vis Sci. 2011; 52:1151-1155) DOI:10.1167/iovs.09-3705

Validity of recall absent schoolchildren to free eye health projects

Purpose: To analyze the results of recall absent schoolchildren to eye health projects. Methods: Cross-sectional study. Visual screening was performed in schoolchildren attending 1st to 4th grades at public schools, from 7 to 10 years-old, to select and forward to complete ophthalmic evaluation. The projects were performed during weekends, at a public school, in the same municipality. Free transportation, food and eyeglasses were offered. A second opportunity of examination was offered to the students who were absent from the first call, with the same facilities. Results: 51,509 schoolchildren had their vision tested, 14,651 (28.4%) were referred for ophthalmic examination. Of these, 8,683 (59.3%) attended the first call, 2,228 (37.3%) attended the recall and 25.5% of parents did not take their children to ophthalmic examination. The need for eyeglasses for children who attended the examination was 23.8% and 32.0% in the first opportunity and recall, respectively. The recall increased the coverage in 15.2% (59.3% to 74.5%). Conclusion: An expressive number of parents (25.5%) did not bring their children to be examined, even at a second opportunity of exam. The facilities offered: access, free examination, transportation and glasses. Children who were absent in the first opportunity and appeared at recall had a greater need for eyeglasses. Recall increased the coverage in 15.2% (59.3% to 74.5%) and it is not recommended when financial resources are limited.

Self-reported hearing loss among elderly individuals in the city of Sao Paulo, Brazil: prevalence and associated factors (SABE Study, 2006)

This article describes the prevalence of self-reported hearing loss in an elderly population in the city of Sao Paulo, Brazil, and associated factors, based on a cross-sectional descriptive and quantitative study. The sample consisted of individuals over 65 years of age selected from census tracts in two stages, with replacement and probability proportional to the population 75 years of age or older. Statistical analysis used Stata 10 with weighted data, Rao-Scott test, and backward stepwise Poisson regression. 1,115 elders were interviewed. Prevalence of self-reported hearing loss was 30.4%, and higher levels were associated with age over 75 years, male gender, self-reported musculoskeletal conditions, dizziness, visual impairment, and difficulty using the telephone. Increased knowledge of factors associated with hearing loss would support public policies on hearing. The high prevalence found in this study underlines the importance of addressing this issue among the elderly.

A study of pent-up demand in ophthalmology: Divinolandia Hospital/Unicamp

Objective: To assess the waiting time for eye care identifying the number of patients with each complaint; to investigate how the waiting time may worsen the patient's condition; to check the screening of urgent cases for effectiveness; and to devise means of increasing the medical-surgical care capacity. Methods: A retrospective descriptive survey was conducted using data obtained on 12 occasions during collaborative team visits to provide eyecare services. These initiatives were designed to decrease the waiting time and to treat urgent cases that occurred on each occasion; eyecare services were provided every Saturday, in the period from June to August 2006, in 16 cities of the region covered by Conderg (Consortium for the Development of the Sao Joao da Boa Vista Administrative Region). Results: Referrals used 1,743 (87.1%) of the 2,000 places available. The most frequent diagnoses were refractive errors, with 683 cases, corresponding to 39.1% of the total, followed by cataracts, with 296 cases, corresponding to 20.9%. Of the 238 surgeries indicated, 54.6% were phakectomies. Thirty-five (2.0%) cases were considered urgent. Conclusion: The most common diagnoses made during the team visits to manage the excess demand for eyecare were refractive errors and cataracts, which, together, accounted for the majority of the cases. The Divinolandia Hospital has the necessary human and material resources to meet the demand left unattended by the local SUS network. Immediate referral of urgent cases by the primary units' screeners proved effective.

Optical aids for low vision: use of the Internet to guide teachers of the visually impaired

PURPOSES: To describe and interpret teachers' opinions about and responsiveness to guidance on optical aids for low vision. METHODS: It was conducted a cross-sectional analytical study. The convenience, non-random sample consisted of 58 teachers from the public school network of the city of Campinas. It was constructed and applied a structured questionnaire, available online at the assessed website. For qualitative data collection it was conducted an exploratory study using the focus group technique. RESULTS: Responses expressed, for the most part, a marked interest in the website, its easiness of access, and the comprehensive nature of the information provided. Most people reported frequent use of the Internet to seek information, and found it easier to access the Internet at home. Among the qualitative aspects of the evaluation, we should mention the perceived importance of the website as a source of information, despite some criticism about the accessibility and reliability of the information found on the Internet. CONCLUSION: Teachers' need for training to deal with visually impaired students and their positive response to advice and information lead to the conclusion that web-based guidelines on the use of optical aids were considered beneficial to ease the understanding of visual impairment and the rehabilitation of the affected subjects.

Electrophysiological evidence for impairment of contrast sensitivity in mercury vapor occupational intoxication

Contrast sensitivity (CS) was evaluated in 41 former workers from a lamp manufacturing plant who were on disability retirement due to exposure to mercury and 14 age-matched controls. The CS was measured monocularly using the sweep visual evoked potential (sVEP) paradigm at 6 spatial frequencies (0.2, 0.8, 2.0, 4.0, 15.0, and 30 cpd). Statistical difference (p < 0.05) was found between the controls and the patient right and left eyes for 2.0 and 4.0 cpd. According the results in those spatial frequencies the eyes were classified in best and worst. Statistical differences were found between the controls and the best eyes for 2.0 and 4.0 cpd and for 0.8, 2.0, and 4.0 cpd for their worst eyes. No correlation was found between CS results and the time of exposure (mean 8.9 yr +/- 4.1), time away from the mercury source (mean = 6.0 yr +/- 3.9), urinary mercury level at the time of work (mean = 40.6 mu g/g +/-36.3) or with the mercury level at the CS measurement time (mean = 1.6 mu g/g +/-1.1). We show the first evidence of a permanent impairment in CS measured objectively with the sVEP. Our data complement the previous psychophysical works reporting a diffuse impairment in the CS function showing a CS reduction in the low to middle spatial frequencies. In conclusion, non-reversible CS impairment was found in occupational exposure to mercury vapor. We suggest that CS measurement should be included in studies of the mercury effects of occupational exposure. (C) 2007 Elsevier Inc. All rights reserved.

Construção e Evidências Psicométricas de uma Escala de Avaliação da Percepção Visual

Este estudo teve como objetivo construir e conhecer os parâmetros psicométricos de um instrumento para análise da percepção visual de adultos. Para a construção da escala participaram 295 adultos saudáveis, sem déficits cognitivos ou perceptivo-visuais. Nesta etapa foi formulada uma escala tetrafatorial constituída por 20 itens que avaliam quatro dimensões referentes à percepção visual: constância da forma, figurafundo, posição e relação espacial. Para obter evidências de validade foi utilizada uma amostra de 183 voluntários com boa saúde física e mental e acuidade visual normal ou corrigida. Os dados obtidos relatam a existência de concordância interjuízes, adequação semântica e significância no teste-reteste do instrumento. Os coeficientes de fidedignidade variaram de 0,84 a 0,93. Os quatro fatores esperados foram encontrados, cada um contendo 5 itens, e juntos explicaram 57,52% da variância do constructo. O instrumento apresentou parâmetros psicométricos adequados, o que pode justificar sua utilidade em pesquisas básicas e na prática clínica.

Long-Term Occupational Exposure to Organic Solvents Affects Color Vision, Contrast Sensitivity and Visual Fields

The purpose of this study was to evaluate the visual outcome of chronic occupational exposure to a mixture of organic solvents by measuring color discrimination, achromatic contrast sensitivity and visual fields in a group of gas station workers. We tested 25 workers (20 males) and 25 controls with no history of chronic exposure to solvents (10 males). All participants had normal ophthalmologic exams. Subjects had worked in gas stations on an average of 9.6 +/- 6.2 years. Color vision was evaluated with the Lanthony D15d and Cambridge Colour Test (CCT). Visual field assessment consisted of white-on-white 24-2 automatic perimetry (Humphrey II-750i). Contrast sensitivity was measured for sinusoidal gratings of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0 and 20.0 cycles per degree (cpd). Results from both groups were compared using the Mann-Whitney U test. The number of errors in the D15d was higher for workers relative to controls (p<0.01). Their CCT color discrimination thresholds were elevated compared to the control group along the protan, deutan and tritan confusion axes (p<0.01), and their ellipse area and ellipticity were higher (p<0.01). Genetic analysis of subjects with very elevated color discrimination thresholds excluded congenital causes for the visual losses. Automated perimetry thresholds showed elevation in the 9 degrees, 15 degrees and 21 degrees of eccentricity (p<0.01) and in MD and PSD indexes (p<0.01). Contrast sensitivity losses were found for all spatial frequencies measured (p<0.01) except for 0.5 cpd. Significant correlation was found between previous working years and deutan axis thresholds (rho = 0.59; p<0.05), indexes of the Lanthony D15d (rho = 0.52; p<0.05), perimetry results in the fovea (rho = -0.51; p<0.05) and at 3, 9 and 15 degrees of eccentricity (rho = -0.46; p<0.05). Extensive and diffuse visual changes were found, suggesting that specific occupational limits should be created.

Language impairment in Huntington's disease

Language alterations in Huntington's disease (HD) are reported, but their nature and correlation with other cognitive impairments are still under investigation. This study aimed to characterize the language disturbances in HD and to correlate them to motor and cognitive aspects of the disease. We studied 23 HD patients and 23 controls, matched for age and schooling, using the Boston Diagnostic Aphasia Examination, Boston Naming Test, the Token Test, Animal fluency, Action fluency, FAS-COWA, the Symbol Digit Modalities Test, the Stroop Test and the Hooper Visual Organization Test (HVOT). HD patients performed poorer in verbal fluency (p<0.0001), oral comprehension (p<0.0001), repetition (p<0.0001), oral agility (p<0.0001), reading comprehension (p=0.034) and narrative writing (p<0.0001). There was a moderate correlation between the Expressive Component and Language Competency Indexes and the HVOT (r=0.519, p=0.011 and r=0.450, p=0.031, respectively). Language alterations in HD seem to reflect a derangement in both frontostriatal and frontotemporal regions.