Abstract
Purpose :
The objective of this study is to establish a rabbit model of posterior penetrating eye injury as a platform to test potential therapeutics. Retinal wound healing can lead to intraocular fibrosis and may cause vision loss. Although there have been many advances in surgical management to repair the retina, the continuous scarring in the eye after surgery eventually leads to severe vision loss or blindness. Effective therapeutics are not available to treat this blinding disorder.
Methods :
To study ocular fibrosis in animal models, a detailed classification system has been developed. Intraocular fibrosis in animals is graded according to the Fastenberg scale of classification: stage 0, no disease; stage 1, epiretinal membrane formation; stage 2, vitreoretinal traction without retinal detachment; stage 3, localized retinal detachment; stage 4, extensive retinal detachment ; stage 5, complete retinal detachment. 10 male Dutch Belted rabbits were divided into groups as listed in Table 1. While under anesthesia, posterior penetrating eye injury was induced in the right eye with the left eye acting as the uninjured control. Injured and control eyes were examined by intraocular pressure measurement, indirect ophthalmoscope, fundus photography, and electroretinography on post –injury days as indicated in Table 1. Group A was euthanized on Day 14 to determine fibrosis at an early phase of disease progression. Group B was euthanized on Day 28 to examine fibrosis at a late phase of disease progression. The eyes were processed for histology and immunofluorescence labeling of fibrotic proteins alpha-smooth muscle actin and collagen I.
Results :
Rabbits were examined at both 14 and 28 days post injury. Early fibrosis was detected by day 14, as indicated by indirect ophthalmoscopy and fundus imaging. Fibrotic membranes were visible at the site of original injury. Immunofluorescence analysis detected alpha-smooth muscle actin and collagen I within the fibrotic membranes.
Conclusions :
These data have shown that ocular fibrosis can be detected within 14 days after the initial injury, with more severe fibrosis detected at 28 days post-injury. The detection of intraocular fibrosis at any stage from 1 to 5, at any time point, was considered successful development of this model. The results of this study will be used to determine the optimal time points for later studies designed to test treatment strategies.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.