Cilioretinal artery occlusion in antiphospholipid syndrome and the decision to anticoagulate

A patient in her late 50s with antiphospholipid syndrome presented to general ophthalmology clinic for annual hydroxychloroquine retinopathy screening. She had taken 400 mg hydroxychloroquine daily for over a decade. She denied any visual changes and visual acuity was 20/20. Her examination and fundus photos were normal, but macular optical coherence tomography of the right eye demonstrated inner retinal atrophy and visual field tests revealed a corresponding paracentral scotoma, consistent with a prior cilioretinal artery occlusion. Prior testing from visits with other ophthalmologists revealed that this occlusion had occurred previously, but she had only been informed of not having hydroxychloroquine retinopathy. The possibility of vision loss prompted her to reconsider her prior decision to discontinue anticoagulation. This case demonstrates how anchoring bias may lead clinicians astray, and how the risk of blindness is a strong motivator for patients regarding anticoagulation.