Optical Coherence Tomography (OCT) System, Image Acquisition, and Analysis

OCT images were taken as described previously.¹² Briefly, images were acquired using the Bioptigen Envisu R2300 (Bioptigen, Inc., Morrisville, NC). Animals were anesthetized and eyes were dilated with phenylephrine (2.5%, Akorn, Inc., Lake Forest, IL) and corneal protection provided by Genteal (Alcon Laboratories, Inc. Fort Worth, TX). Animals were wrapped in warming gauze and placed in the prone position on the Bioptigen mouse imaging cassette. For the anterior chamber, 3.6 × 3.6 mm images (1000 A-lines/B-Scan × 400 B-scans) were captured using a Bioptigen 12-mm telecentric lens (product # 90-BORE-G3-12; Bioptigen, Inc., Wetzlar, Germany). For posterior chamber imaging, 1.6 × 1.6 mm images (1000 A-lines/B-scan × 200 B-scans) were captured using the Bioptigen mouse retina lens (product # 90-BORE-G3-M; Bioptigen, Inc., Wetzlar, Germany). The degree of clinical inflammation was determined by counting the number of inflammatory cells present in the aqueous or vitreous on an OCT B-scan image. Cell counts were performed by a manual grader masked to eye, treatment, and day. An inflammatory cell was defined as a discrete hyper-reflective dot in the aqueous on anterior segment OCT images or in the vitreous on posterior segment OCT images.