Sd oct instrument

OCT was used to analyze the structure of the retina in 2% isoflurane (Baxter, Deerfield, IL, USA)-anesthetized mice using a SomnoSuite (Kent Scientific, Torrington, CT, USA). Prior to imaging, pupils were dilated using 1% tropicamide (Alcon Laboratories, Geneva, Switzerland). GenTeal gel (Alcon Laboratories, Alcon, Geneva, Switzerland) was placed on the corneal surface for preservation of corneal integrity. OCT images were obtained using an SD-OCT instrument (Bioptigen, Morrisville, NC, USA). Thickness of the RNFL, RGC, and the inner plexiform layer (IPL) was measured manually using calipers provided by the software. Briefly, thickness was measured between the borders of the RNFL from the inner limiting membrane and the outer borders of the IPL (referred to as the RGC/IPL complex) in the superior, inferior, nasal, and temporal quadrants 400 µM away from the optic nerve head (36 (link); Figure 2). Data from eyes with indistinguishable retinal layer borders were excluded from future analysis.

OCT was used to analyze the structure of the retina in vivo and the measurement of the ganglion cell layer, including the retinal never fiber layer (RNFL) and the inner plexiform layer (GCL/IPL) complex; thickness was measured as described previously [20 (link)]. Briefly, borders of the RNFL and the IPL were determined manually, and thickness was measured at a distance of 400 µm away from the center of the optic nerve head in the superior, inferior, nasal, and temporal quadrants. At week 8, all remaining mice of both cohorts were anesthetized with intraperitoneal injection of ketamine (30 mg/kg, Mylan) with xylazine (5 mg/kg, Akorn Inc.). Pupils were dilated using 1% tropicamide (Alcon). OCT images were obtained using an SD-OCT instrument (Bioptigen, Morrisville, NC, USA) and the average regional GCL/IPL complex thickness was calculated as an indicator of RGC degeneration. Data of mouse eyes from 46 naïve animals, 49 EAE mice, and 28 EAE mice that underwent GA treatment were used for statistics. OCT data were excluded either because of poor images or questionable detection of borders between retinal layers.