We present a case of ocular ischemic syndrome (OIS) caused by heparin-induced thrombocytopenia with thrombosis (HITT).

HITT is an antibody-mediated response leading to thrombocytopenia and increased risk of thrombosis in 25 to 50% of affected patients. OIS is caused by ocular hypoperfusion associated with severe carotid artery stenosis. Symptoms include visual loss and ocular pain. 

Informed consent obtained from patient.

A 61-year-old man with hypertension and peripheral arterial disease with recent femoral artery stent (FAS) placement presented with sudden-onset left eye pain and vision loss. On exam, left eye with non-reactive mydriasis, ophthalmoplegia, ptosis, and absent light perception without additional cranial nerve deficits, weakness, paresthesia, or incoordination. Initial presentation prompting concern for intra-ocular or orbital etiology rather than neurovascular cause. CTA of brain and neck remarkable for absent filling left ICA cervical to supraclinoid. MRI brain showed embolic ischemic strokes in the left frontal and occipital lobes. The following day, he endorsed left lower extremity pain, which on exam was paretic and numb, cold to touch and pulseless distal to mid-calf. Follow-up imaging revealed thoracic and abdominal aorta thrombi and re-occlusion of the FAS. During his recent hospitalization for this procedure, platelet count was 274, and he received unfractionated and subcutaneous heparin. However, on current presentation, platelet count was 44. He was started on argatroban due to concern for HITT, later confirmed with positive SRA and PFF4 antibodies. On argatroban, TCD EDS revealed fewer microemboli than initially. Patient was additionally treated with IVIG and steroids and transitioned from argatroban to fondaparinux. Ultimately, discharged with little improvement in ocular symptoms.

OIS is a rare complication of HITT, occurring within two weeks of repeat exposure to heparin following initial exposure within three months. Awareness of both conditions is crucial to guide prompt management and optimal care to prevent neurologic sequelae.