Peripapillary Halo in Inflammatory Papillitis of Birdshot Chorioretinopathy.

Purpose Peripapillary halos (PPH) are peripapillary changes observed surrounding the optic nerve head in normal eyes and eyes with different disorders. Recognizing the microstructure and mechanism of development of these halos will help clinicians understand the different associated retinal and optic nerve head pathologies. We describe the in vivo histological characteristics of PPH in birdshot chorioretinopathy (BSCR). Patients and methods This was a prospective observational case-series in a single tertiary referral center. Six eyes of three patients with PPH associated with BSCR were determined through clinical examination, fundus photography, and fundus autofluorescence (FAF). Patients underwent swept-source optical coherence tomography (SS-OCT) imaging of the optic nerve head and peripapillary region. Results In SS-OCT B-scans across the area of PPH, we observed thinning and interruption of retinal pigment epithelium (RPE)-Bruch's membrane complex. These halos are a circumferential form of alpha zone RPE-associated crescentic peripapillary atrophy (PPA), unlike the PPH observed with myopia and normal aging. Conclusion PPH in BSCR patients may be a sign of prior inflammatory optic neuropathy.