Diagnostic Evaluation of Ocular Toxocariasis Using High-Penetration Optical Coherence Tomography

PURPOSE To study a case with intraretinal Toxocara larvae in a granuloma using high-penetration optical coherence tomography (HP-OCT). METHODS A 50-year-old man, who was referred to our clinic with ocular toxocariasis, initially presented with granuloma formation in the retina. We followed the treatment-associated changes in the toxocariasis lesion by a series of examinations using HP-OCT before and after a systemic corticosteroid and anthelmintic therapy. RESULTS The posterior pole granuloma initially appeared as a yellowish-white intraretinal lesion with an exudative focus and dye leakage seen on angiography. After therapy, the lesion was no longer exudative. During treatment-free periods, an intraretinal lesion was seen protruding from the retinal surface into the vitreous cavity. HP-OCT confirmed the elevated lesion protruding from the retinal surface into the vitreous cavity. With treatment, the protruding focus flattened during the following 8 months, but the lesion recurred after the treatment stopped. CONCLUSIONS The findings and clinical course strongly suggested ocular toxocariasis. The protruding retinal lesion may have been an ocular manifestation of toxocariasis. HP-OCT was useful in the follow-up and diagnosis.