Micron oct

Fundus photographs were taken 3 to 4 months post injections with a Micron III (Phoenix Research Labs, Pleasanton, CA, USA) system equipped with an excitation filter at 482 nm and an emission filter at 536 nm. In addition, OCT scans and corresponding retinal fundus images were taken using the Phoenix Image-Guided OCT (Phoenix Research Labs) and Micron IV, respectively. Images were captured post injection at indicated time points using Micron OCT and StreamPix 5 commercial software (Phoenix Research Labs). Animals were anesthetized with an intraperitoneal injection of ketamine (85 mg/kg) and xylazine (5 mg/kg) 20 minutes prior to fundus imaging. The distribution of the GFP signals of the central retina was measured utilizing ImageJ (http://rsb.info.nih.gov/ij/ index.html; in the public domain). Briefly, photographs centered on the optic disc were used; the photographs were converted into grayscale 8-bit images, and an intensity threshold was applied to select GFP-positive areas from background signals. The number of GFP-positive pixels was counted and the percentage of positive pixels in the image was calculated. Statistical analyses were performed using Prism 7 (GraphPad Software, La Jolla, CA, USA).