Medical Mystery Cases

Amazing answers, everyone!

The correct diagnosis is central retinal artery occlusion (CRAO) with cilioretinal artery (CLRA) sparing. Unfortunately, this patient suffered severe vision loss that never recovered.

In some cases of CLRA sparing, the macula remains perfused and central vision can be preserved. Unfortunately, the cilioretinal artery in this patient did not provide enough blood flow to maintain useful vision.

CRAO is a devastating condition and is often described as the eye equivalent of a stroke. When a patient presents with a CRAO, it should immediately raise concern for an underlying vascular problem elsewhere in the body. In fact, patients are at dramatically increased risk of developing a true brain stroke shortly after a CRAO event. One study quoted up to a 70 fold increase of stroke in the first week following a CRAO event!

Because of this, CRAO is considered a medical emergency. Whenever I diagnose a CRAO, I immediately contact the patient's primary care physician and arrange urgent stroke evaluation. This workup typically includes carotid ultrasound, echocardiography, and blood testing (including ESR and C-reactive protein).

Looking back at the fundus photograph, Claire and Connor were exactly right! The key abnormality is the diffuse retinal whitening/opacification involving the posterior pole, which represents ischemic injury to the retina. The well-demarcated wedge-shaped area extending from the optic nerve toward the fovea (the papillomacular bundle) is actually the area supplied by the cilioretinal artery and therefore remained perfused.

Interestingly, that wedge-shaped region can sometimes be mistaken for hemorrhage. However, the fluorescein angiogram demonstrates that it is actually the only area of retina showing normal perfusion and early filling.

The OCT is also classic for acute CRAO, showing diffuse hyperreflectivity and thickening of the inner retinal layers, reflecting retinal ischemia.

The underlying cause in this patient was discovered on carotid ultrasound, which revealed significant atherosclerotic plaque involving both the common and internal carotid arteries. The patient was referred to Cardiology and Vascular Surgery, and aggressive risk-factor modification was recommended, including smoking cessation, blood pressure control, and cholesterol management.

Despite treatment and systemic evaluation, the patient's final visual acuity in the affected eye remained hand motion.

Great job working through this case and identifying the key imaging findings!