Unusual eye findings in a patient with atypical hemolytic uremic syndrome: Answers

At first glance, development of ocular findings in a case with aHUS, suggested ischemic retinopathy secondary to aHUS. However, ophthalmology consultation suggested that ocular toxocariasis, persistent fetal vasculature (PFV), familial exudative vitreoretinopathy (FEVR), and retinopathy of prematurity (ROP) were considered in the differential diagnosis because of the tractional retinal detachment (TRD).

ROP and FEVR were excluded since there was no history of prematurity or family history for FEVR. Although there was no history of contact with cat or dog, the diagnosis of ocular toxocariasis could not be excluded because of the unilaterality of the disease and presence of inflammatory findings (2–3( +) inflammatory cells) in fundus examination. Toxocara IgM and IgG blood tests can be measured for toxocariasis. However, negativity of blood tests (toxocara IgM and IgG) does not rule out ocular toxocariasis, but detection of a positive result supports the diagnosis. Also ophthalmic ultrasonography (USG), optical coherence tomography (OCT), and fluorescein angiography (FA) are most useful in the differential diagnosis for TRD and also ocular ischemia.

Since ocular toxocariasis could not be excluded with these findings, oral albendazole 20 mg/kg/day (5 days) and 1 mg/kg/day prednisolone (tapered slowly within 6 weeks) treatments were started, while she received eculizumab therapy, and an elective vitreoretinal surgery was planned. Vision improved to 20/400 and inflammatory cells in the vitreous decreased gradually to disappear totally within a 5-month period. The parents refused the option of vitreoretinal surgery, and she was followed up conservatively afterwards. She could not tolerate patching of the fellow eye for amblyopia treatment. During follow-up, color fundus pictures, OCTs, and FA examinations could be performed, and the findings were stable afterwards (Fig. 1). Her last examination after 5 years of follow-up revealed a visual acuity (VA) of 20/25 in the right eye (RE) and counting fingers from 1 m in the left eye (LE), esotropia of the LE, bilateral mild to moderate posterior subcapsular cataracts, and normal intraocular pressures and normal fundus examination in the RE and stable TRD findings in the LE. She continues to receive eculizumab therapy. Also, supportive treatment is continued for kidney failure as her glomerular filtration rate (GFR) is 60 ml/dk/1.73 m².