M B Sherwood1, D W Esson, A Neelakantan, D A Samuelson. 1. Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida 32610-0284, USA. Sherwood@eye.ufl.edu
Abstract
PURPOSE: The most common reason for long-term failure of glaucoma filtering surgery (GFS) is scarring of the external filtering "bleb" tissues. The identification of the factors that mediate this process, as well as the development and initial testing of new therapies to limit scarring is enhanced by the use of appropriate animal models. The standard animal model for studying GFS is the rabbit but newer investigative tools that examine changes induced in biologic systems at a genetic level have made development of a rat model desirable. METHODS: Glaucoma filtering surgery was performed on 20 Sprague-Dawley rats by introducing a 30-gauge silicone cannula through a penetrating scleral tunnel, under a limbal-based conjunctival flap and suturing the conjunctiva closed. Identical GFS was performed on 3 additional rats, which underwent histologic evaluation at days 2, 5, and 11, following surgery.Fistulizing surgery was also performed on 6 Sprague-Dawley rats, for comparison, by creating a full-thickness needle sclerostomy under a limbal-based conjunctival flap and suturing the conjunctiva closed. RESULTS: Following the cannula GFS, well-elevated filtering blebs formed and these gradually failed over the course of 8 to 13 days. Needle tract sclerostomy filtering blebs formed at the site of the fistulizing surgery but rapidly failed over the course of 2 to 3 days. CONCLUSION: Cannulated filtering surgery in the rat provides a longer lasting and more predictable model than needle tract sclerostomy for studying wound healing following GFS and may facilitate the study of induced changes at the gene level.
PURPOSE: The most common reason for long-term failure of glaucoma filtering surgery (GFS) is scarring of the external filtering "bleb" tissues. The identification of the factors that mediate this process, as well as the development and initial testing of new therapies to limit scarring is enhanced by the use of appropriate animal models. The standard animal model for studying GFS is the rabbit but newer investigative tools that examine changes induced in biologic systems at a genetic level have made development of a rat model desirable. METHODS:Glaucoma filtering surgery was performed on 20 Sprague-Dawley rats by introducing a 30-gauge silicone cannula through a penetrating scleral tunnel, under a limbal-based conjunctival flap and suturing the conjunctiva closed. Identical GFS was performed on 3 additional rats, which underwent histologic evaluation at days 2, 5, and 11, following surgery.Fistulizing surgery was also performed on 6 Sprague-Dawley rats, for comparison, by creating a full-thickness needle sclerostomy under a limbal-based conjunctival flap and suturing the conjunctiva closed. RESULTS: Following the cannula GFS, well-elevated filtering blebs formed and these gradually failed over the course of 8 to 13 days. Needle tract sclerostomy filtering blebs formed at the site of the fistulizing surgery but rapidly failed over the course of 2 to 3 days. CONCLUSION: Cannulated filtering surgery in the rat provides a longer lasting and more predictable model than needle tract sclerostomy for studying wound healing following GFS and may facilitate the study of induced changes at the gene level.
Authors: Zachary L Lukowski; Jeff Min; Ashley R Beattie; Craig A Meyers; Monica A Levine; Glenn Stoller; Gregory S Schultz; Don A Samuelson; Mark B Sherwood Journal: J Glaucoma Date: 2013-02 Impact factor: 2.503
Authors: Li-Fong Seet; Wing Sum Lee; Roseline Su; Sharon N Finger; Jonathan G Crowston; Tina T Wong Journal: Mol Med Date: 2011-01-11 Impact factor: 6.354
Authors: Xuyang Liu; Carol A Rasmussen; B'ann T Gabelt; Curtis R Brandt; Paul L Kaufman Journal: Surv Ophthalmol Date: 2009 Jul-Aug Impact factor: 6.048
Authors: Jeff Min; Zachary L Lukowski; Monica A Levine; Craig A Meyers; Ashley R Beattie; Gregory S Schultz; Don A Samuelson; Mark B Sherwood Journal: PLoS One Date: 2012-04-30 Impact factor: 3.240