OCT AND OCT-A FINDINGS IN GIANT CELL ARTERITIS: PAMM as a Specific Ischemic Marker

To assess the diagnostic value of tomographic signs on OCT and OCT-A, particularly paracentral acute middle maculopathy (PAMM), in predicting temporal artery biopsy (TAB) positivity in suspected giant cell arteritis (GCA), irrespective of ophthalmologic involvement.

This prospective monocentric study included patients referred for TAB between January and October 2023. All underwent bilateral macular and optic nerve OCT and OCT-A using AngioPlex CIRRUS HD-OCT (Carl Zeiss Meditec). TAB-positive patients were considered biopsy-proven GCA. Primary analysis focused on the association between PAMM and TAB positivity. Secondary analysis explored vascular choroidal index (CVI), radial peripapillary capillaries (RPC), and OCT-A abnormalities.

Among 70 patients, 22 (31%) had positive TAB. PAMM was observed exclusively in TAB+ patients (n = 8), with specificity and positive predictive value of 100%. Sensitivity and negative predictive value were 38.1% and 77.6%, respectively. Homolateral anterior ischemic optic neuropathy (AION) was always associated with GCA. CVI and other OCT-A findings did not differ significantly between groups. RPC density was significantly reduced in eyes with ophthalmologic involvement ( P = 0.017).

PAMM is a highly specific OCT sign of TAB positivity in suspected GCA. This noninvasive marker may support early therapeutic decisions in suspected GCA.