The Concentration of Tra n s forming Growth Factor-beta2 from Rabbit Eye by Laser Retinal Photocogulation

ABSTRACT

Laser photocoagulation is commonly used for the treatment of retinal neo-vascularization in ischemic retinal diseases. Transforming growth factor-beta2 is known to be produced by RPE cells after laser photocoagulation and to be related to both regression of neovascularization and acceleration of preretinal fibrosis. In this study, we investgated the safe extent of laser photocoagulation not promoting the fibrosis by measuring intravitreal TGF-beta2 released following treatment. In gray rabbit eyes, trans pars plana vitrectomies and laser photocoagulations[1/8, 1/4, 1/2 of the fundus]were performed. The each eyeball was enucleated and TGF-beta2 concentration was measured at 12, 24, 72 hours after laser photocoagulation. And fibrotic activity was observed by the subconjunctival injection of fibrocyte and TGF-beta2 [0.1, 1, 10ng/milliliter]. The results were as follows1. When TGF-beta2 was injected subconjunctivally along with fibrocytes, fibrocytic activity was observed found at the concentration of 1 or 10ng/milliliter of TGF-beta2. 2.The intravitreal concentration of TGF-beta2 after laser photocoagulation to the 1/8, 1/4, 1/2 of fundus area were 0.05, 0.1, 0.2ng/milliliter respectively. From the above results, we suggest to treat limit the area of laser photo-coagulation to 1/8 of fundus area in order to prevent the retinal fibrosis.