Ultrasound biomicroscopy in peripheral retinovitreal toxocariasis

PURPOSE: To report ultrasound biomicroscopic features in peripheral retinov itreal Toxocara uveitis, METHODS: Three patients with unilateral vitreitis suspected to be caused by peripheral toxocariasis were referred for ultrasound biomicroscopic examin ation of the peripheral retina, pars plana, and adjacent vitreous. RESULTS: In two of the three patients, characteristic pseudocystic transfor mation of the peripheral vitreous was seen. In both patients, Toxocara sero logy was positive and eosinophilia was present. In the third patient, no ps eudocystic transformation of the peripheral vitreous was seen; however, the re was the dense thickening adjacent to the pars plana usually seen by ultr asound biomicroscopy in pars planitis and corresponding to clinically visib le snowbanks, The third patient had a negative Toxocara set ology and later developed bilateral intermediate uveitis of the pars planitis type. In non e of 48 patients with diverse inflammatory conditions of the retroiridal sp ace that were examined by ultrasound biomicroscopy were the characteristic Toxocara associated pseudocystic images seen. CONCLUSIONS: Pseudocystic transformation of the peripheral vitreous appears to be a rather specific and sensitive ultrasound biomicroscopic sign in pa tients with presumed peripheral toxocariasis that will likely aid diagnosis in difficult cases. (C) 1999 by Elsevier Science Inc. All rights reserved.