Characteristics associated with anterior ischemic optic neuropathy (AION) in giant cell arteritis (GCA).

Objective: Giant cell arteritis (GCA) is the most common vasculitis and can result in blindness due to anterior ischemic optic neuropathy (AION). Little is known about which patients with GCA are at higher risk of AION.  We did a retrospective chart review to compare demographics, past medical history, labs and imaging of GCA patients with and without AION.

Methods: All patients at the University of Washington who were diagnosed with GCA by a rheumatologist, had a vascular ultrasound and met classification criteria for GCA were included. AION was diagnosed by an ophthalmologist. To compare demographics, symptoms, presentation imaging and lab findings, we used Pearson Chi-square, Fisher's exact test and t-tests to compare GCA patients with and without AION.

Results: 91 patients with GCA without vision loss were compared to 15 patients with GCA and AION. The AION group had significantly more men (p=0.03) and elevated C-reactive protein (CRP) as compared to the non-AION group (p = 0.04). Rates of hypertension, smoking, erythrocyte sedimentation rate (ESR) and classification scores were similar. Vascular ultrasound showed similar rates of small and large vessel vasculitis, but the AION group had higher halo scores, with the AION group having a mean score of 5 and patients with GCA and without AION having a mean score of 3 (p < 0.01).

Conclusions: Older men with GCA and more than three halos on vascular ultrasound imaging of GC may be at higher risk of AION. Key Points • This is the first paper to incorporate the use of vascular ultrasound in comparing patients with anterior ischemic optic neuropathy (AION) to those without giant cell arteritis (GCA). • Male sex is associated with AION despite GCA being more common in women. • Older age and higher CRP are associated with AION. • GCA patients with AION had a higher halo score than GCA patients without AION.