Optic Disc Edema Is an Under-Recognized Feature of Birdshot Chorioretinitis.

BACKGROUND: Optic disc edema is a feature of many ophthalmic and neurologic conditions. It remains an underappreciated feature of birdshot chorioretinitis (BSCR), leading to delay in diagnosis and treatment. The purpose of our study was to identify clinical features that are concomitant with optic disc edema and suggest a diagnosis of BSCR. METHODS: Retrospective multicenter case series of 29 patients who were referred to a neuro-ophthalmologist or uveitis specialist for evaluation of disc edema and were ultimately diagnosed with BSCR. RESULTS: Fifty-four eyes of 30 patients, from the practices of 15 uveitis specialists, met the eligibility criteria. In addition to disc edema, concomitant features in all patients included vitritis, chorioretinal lesions, and retinal vasculitis. Visual recovery to 20/40 or better occurred in 26 of 29 patients. Visual acuity remained 20/100 or worse in 2 patients previously diagnosed with idiopathic intracranial hypertension, 1 patient previously diagnosed with optic neuritis, and 1 patient for whom treatment was delayed for years, leading to optic disc atrophy. CONCLUSIONS: Optic disc edema is a presenting feature in some cases of BSCR. A diagnosis of BSCR should be considered when disc edema occurs with vitritis, chorioretinal inflammation, and retinal vasculitis. Patients should be referred to a uveitis specialist for treatment.

Sortase-Modified Cholera Toxoids Show Specific Golgi Localization.

Cholera toxoid is an established tool for use in cellular tracing in neuroscience and cell biology. We use a sortase labeling approach to generate site-specific N-terminally modified variants of both the A2-B5 heterohexamer and B5 pentamer forms of the toxoid. Both forms of the toxoid are endocytosed by GM1-positive mammalian cells, and while the heterohexameric toxoid was principally localized in the ER, the B5 pentamer showed an unexpectedly specific localization in the medial/trans-Golgi. This study suggests a future role for specifically labeled cholera toxoids in live-cell imaging beyond their current applications in neuronal tracing and labeling of lipid rafts in fixed cells.