Multimodal Imaging in Ocular Toxoplasmosis.

Multimodal imaging relies on combination of multiple imaging modalities to precisely delineate pathological changes in the posterior segment of the eye associated with a wide range of conditions. This combined application of fundus photography, optical coherence tomography, fundus reflectance/autofluorescence and fundus angiography (with fluorescein, indocyanine green and/or optical coherence tomography) is of great utility for assessment of patients with ocular toxoplasmosis. Multimodal imaging is helpful to characterize the typical pattern of toxoplasmic retinochoroiditis, with primary focal inflammatory involvement of the neurosensory retina, and secondary changes at the level of underlying choroid, retinal blood vessels, vitreous and even optic disc. It may also be valuable to document and follow local complications, including macular edema, vascular occlusions, and choroidal neovascularization, among others.

OUTCOMES AFTER PARS PLANA VITRECTOMY FOR EPIRETINAL MEMBRANES ASSOCIATED WITH TOXOPLASMOSIS.

PURPOSE: To evaluate outcomes and complications of pars plana vitrectomy in patients with epiretinal membrane secondary to toxoplasmic retinochoroiditis. METHODS: Retrospective evaluation of the records of 14 patients who underwent pars plana vitrectomy for epiretinal membrane secondary to toxoplasmic retinochoroiditis. The best-corrected visual acuity, intraoperative and postoperative complications, and macular optical coherence tomography were analysed. All patients received postoperative prophylactic treatment with trimethoprim/sulfamethoxazole. RESULTS: Fourteen patients, 5 men and 9 women, were included. Mean follow-up period after surgery was 6.07 ± 2.64 months. Preoperative mean best-corrected visual acuity was 20/200, and postoperative mean best-corrected visual acuity was 20/60. There were no intraoperative complications. Three patients developed posterior capsule opacification, and one patient developed cataract. CONCLUSION: Pars plana vitrectomy is a safe and effective procedure in patients with epiretinal membrane secondary to toxoplasmic retinochoroiditis, improving both visual acuity and anatomical result on macular optical coherence tomography. The most frequent postoperative complications were posterior capsule opacification and cataract. No recurrences of the disease were recorded.

[Ultrasonographic findings in ocular toxocariasis]. / Achados ultrassonográficos em toxocaríase ocular.

PURPOSE: To evaluate ophthalmic ultrasound findings in the three presentation forms of ocular toxocariasis (peripheral or posterior pole granulomas and chronic endophthalmitis), in patients with confirmed diagnosis of ocular toxocariasis. METHODS: 11 patients (11 eyes) with clinical and confirmed diagnosis of active ocular toxocariasis, presented positive ELISA test, were analyzed, prospectively, in the study. The patients were submitted to an ocular ultrasound examination (10-MHz transducer, contact technique). RESULTS: In the series of 11 patients, mean age was 7.9 years-old (range from 2 to 17 y), 73% male, referring previous contact with dogs (91%), and with the soil (50%), no referral of appetite perversion. In the analyses of compromised eyes (11 eyes), the ophthalmoscopic examination revealed the following distribution of the 3 forms of ocular toxocariasis: 7 cases (63.6%), posterior pole granuloma; 1 (9.1%), chronic endophthalmitis; 2 (18.2%), peripheral granuloma; and 1 (9.1%), posterior pole granuloma associated with chronic endophthalmitis. Visual acuity impairment: no light perception (3 eyes, 27.3%); hand motion (4 eyes, 36.4%); counting fingers at 10 cm (1 eye, 9.1%); 20/200 (1 eye, 9.1%); 20/70 (1 eye, 9.1%); undefined (1 eye, 9.1%). Serology was positive to Toxocara canis (ELISA test) in 100% of the cases. Ophthalmoscopy was difficult or impossible in 64% of the cases due to the media opacity. Ultrasound findings noted were vitreous membranes with retinal attachment (100%); parietal lesions (granulomas) with high (80%) or medium (20%) reflectivity. CONCLUSION: The most consistent ultrasound finding in the eye with toxocariasis was a high-reflectivity retinal mass, located in posterior pole or periphery, which may be calcified, and which has as main characteristic the adherence of vitreous membranes. In addition to clinical history, systemic evaluation and serology, the ultrasound can help in the diagnosis of ocular toxocariasis, especially in media opacities.

Ultrasound biomicroscopy findings in peripheral vitreoretinal toxocariasis.

PURPOSE: To describe the morphologic alterations in ultrasound biomicroscopy (UBM) present in peripheral vitreoretinal toxocariasis. METHODS: An observational prospective study of case series. Fifteen eyes of 15 patients with clinical and laboratory diagnosis of peripheral vitreoretinal toxocariasis were enrolled. The patients were submitted to UBM examination of the region corresponding to the pars plana of the affected eye. RESULTS: The most common morphologic alterations found by UBM in patients with peripheral vitreoretinal toxocariasis were as follows: vitreal membranes (13 cases), toxocara granuloma (11 cases), and pseudocysts (8 cases). Other less frequent findings were thickening of the ciliary body (6 cases), cystic formation (2 cases), peripheral retinal detachment (2 cases), rectification of the iris root (1 case), and posterior synechiae (1 case). CONCLUSIONS: UBM allows detection of well-defined morphologic alterations associated with peripheral vitreoretinal toxocariasis, being useful to reinforce the clinical diagnosis.

Experimental intravitreous cysticercosis.

BACKGROUND: Cysticercosis is one of the parasitic diseases that most frequently affects the eye. The most common and severe manifestations of ocular infection are secondary to posterior segment involvement, which often leads to blindness and atrophy of the eye. The pathogenesis of ocular injury in this disease is poorly understood. The authors have developed an experimental animal model for intravitreous cysticercosis using New Zealand rabbits and Taenia crassiceps cysticerci. METHODS: Twelve rabbits were divided into two groups. Rabbits in group I were inoculated with one living cysticercus in the vitreous cavity. Rabbits in group II received an intramuscular dose of steroids prior to inoculation of parasites. RESULTS: An intense inflammatory reaction, which lead to a severe ocular injury, was observed in rabbits of group I, while rabbits in group II had minimal inflammatory changes. Histopathological studies showed a severe histiocytic infiltrate with generalized retinal damage in group I, and a mild inflammatory infiltrate, limited to the area of direct contact with the parasite in group II. The ocular lesions found in rabbits which did not receive steroids (group I) resembled those found in human ocular cysticercosis. CONCLUSION: These observations indicate that ocular damage in this parasitic disease might be directly related to inflammatory changes produced by the presence of cysticerci. This model appears to be useful for future investigations.