Diagnostic evaluation of ocular toxocariasis using high-penetration optical coherence tomography

To study a case with intraretinal Toxocara larvae in a granuloma using high-penetration optical coherence tomography (HP-OCT).

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.

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.

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.