Ocular Toxocariasis Mimicking Persistent Fetal Vasculature in a Child.

Purpose: To report a case of ocular toxocariasis in a child initially suspected to have persistent fetal vasculature (PFV), highlighting the importance of accurate differential diagnosis in cases of retrolental membranes. Methods: A single case was reviewed. Results: A 4-year-old Guatemalan boy presented with a 3-week history of right eye irritation and visual acuity limited to counting fingers. Clinical examination revealed a retrolental membrane extending to the optic nerve, initially suggestive of PFV. Further investigation under anesthesia revealed a visually significant funnel-shaped vitreous cavity devoid of vascularity. Fluorescein angiography showed a peripheral avascular retina with leakage, suggesting a granulomatous lesion. Pars plana vitrectomy and lensectomy revealed a chorioretinal scar in the peripheral inferonasal retina. Serologic testing confirmed the diagnosis of ocular toxocariasis, with the presence of Toxocara immunoglobulin G antibodies and peripheral eosinophilia. Conclusions: Ocular toxocariasis can mimic PFV in pediatric patients presenting with retrolental membranes. Careful clinical evaluation, imaging, surgical exploration, and serologic testing are essential for accurate diagnosis and appropriate management.