RESUMO
PURPOSE: To describe the determinant clinical signs to diagnose diffuse unilateral subacute neuroretinitis (DUSN) and the main features related to identification of the live worm. DESIGN: Retrospective study performed at the Federal University of Rio Grande do Norte, Rio Grande do Norte, Brazil, between 2003 and 2008. METHODS: Patients with early- or late-stage diffuse unilateral subacute neuroretinitis were included. All patients underwent complete ophthalmologic examination and had a minimum of 6 months of follow-up. RESULTS: A total of 121 patients were included. Most patients were younger than 20 years (69.42%). Visual acuity was 20/400 or worse in 86 patients (71.7%). Nine patients (7.43%) presented in the early stage and 112 (92.57%) patients presented in the late stage. Subretinal tracks (91.7%), focal alterations of the retinal pigment epithelium (89.3%), small white spots (80.2%), and optic nerve atrophy (76.9%) were the most frequent clinical features. The subretinal worm was identified in 48 patients (39.66%), and laser treatment to destroy it was performed in all cases. The most common location of the nematode was the posterior pole (21 patients). It was observed that the younger the age, the higher the indices of larvae identification (P=.022). Multifocal yellow-white lesions and vitritis were correlated with identification of the worm (P=.001). Mean logarithm of the minimal angle of resolution visual acuity was 1.466 (20/600) and 1.281 (20/400) before and after laser treatment, respectively (P<.005). CONCLUSIONS: Identification of clinical signs and diagnosis of diffuse unilateral subacute neuroretinitis in its early stage, followed by prompt location and destruction of the worm by photocoagulation, may improve the vision of affected patients.
Assuntos
Infecções Oculares Parasitárias/diagnóstico , Infecções por Nematoides/diagnóstico , Retinite/diagnóstico , Doença Aguda , Adolescente , Adulto , Criança , Pré-Escolar , Infecções Oculares Parasitárias/fisiopatologia , Infecções Oculares Parasitárias/cirurgia , Feminino , Humanos , Fotocoagulação a Laser , Masculino , Infecções por Nematoides/fisiopatologia , Infecções por Nematoides/cirurgia , Retina/parasitologia , Retina/patologia , Retinite/fisiopatologia , Retinite/cirurgia , Estudos Retrospectivos , Acuidade Visual/fisiologia , Adulto JovemRESUMO
OBJECTIVE: To determine the prevalence of systemic and ocular toxoplasmosis among 1024 students in the city of Natal, Northeastern Brazil, and correlate it with demographic, socioeconomic and epidemiological risk factors. METHODS: The study population was randomly selected, asked to fill out a questionnaire, provide a blood sample for IgG and IgM (MEIA) serology and a hemogram, and undergo an eye examination. RESULTS: The seroprevalence for IgG was 46% (95% CI = 42.9-49.2%) and that for IgM was 1.4% (95% CI = 0.8-2.4%). The prevalence of ocular lesions was 1.15% (95% CI = 0.6-2.0%). In the univariate analyses, confirmed by multivariate analysis, the socioeconomic conditions were determinants in the prevalence of systemic and ocular toxoplasmosis (mother's schooling = literacy/OR = 2.9 and p < 0.001). CONCLUSIONS: The prevalence of systemic toxoplasmosis, although high, was lower than that found in studies performed in the South and Southeast of Brazil, and the incidence of ocular lesions was totally different, being lower by a factor varying from 5 to 17. Although important epidemiological variables, such as owning a cat, drinking unfiltered water or having had contact with lakes or rivers, were found to be correlated with toxoplasmosis in the preliminary analysis, they lost their influence when included in the logistic model. However, further studies must be undertaken to identify the reasons for these findings, including the determination of the strains of Toxoplasma gondii encountered in different regions of the country and the sources of the water utilized by these populations.