Central retinal vein occlusion in a patient using the antipsychotic drug olanzapine: a case report

We report our findings in a patient who developed central retinal vein occlusion (CRVO) and was a chronic user of olanzapine, an antipsychotic medication.

A 50-year-old Caucasian man, non-smoker, was referred to our clinic with the chief complaint of floater appearance in his left eye for the past 3 days. His past medical history indicated that he had been taking antipsychotic drugs (olanzapine) for about 3 years, with no other systemic disease or risk factors for CRVO.

In the examination, his best-corrected visual acuity (BCVA) was 0.7 in the left eye. The fundus showed signs of nonischemic CRVO with subhyaloid hemorrhage and intraretinal hemorrhage in the posterior pole and superior and inferior retina, without macular edema, confirmed by optical coherence tomography (OCT).

We ruled out other probable differential diagnoses and risk factors which lead to CRVO through a complete physical exam and blood analysis (complete blood count, glucose, urea, creatinine, lipid profile, erythrocyte sedimentation rate, C-reactive protein, prothrombin time, partial thromboplastin time, Bleeding time (BT), fibrinogen level, proteins, antiphospholipid antibodies, homocysteine blood level, antithrombin III, protein C and S, factor V Leiden, prothrombin mutation, angiotensin-converting enzyme level, other autoantibodies, and human leukocyte antigen [HLA]-B51). Finally, we confirmed the probable side effect of olanzapine in CRVO, which has not been previously reported. A possible pro-thrombogenic mechanism of olanzapine at the molecular level is an affinity for 5-HT_2Aserotonin receptors. Blocking these receptors results in increased platelet aggregation and increased blood coagulability.

These results indicate that CRVO can be a complication of chronic use of antipsychotic medications such as olanzapine, as shown for the first time in our case report. Clinicians should question patients who develop a sudden CRVO whether they are using antipsychotic medications such as olanzapine.