Abstract
Abstract: :
Purpose: To investigate the intraocular distribution kinetics of 2.5s nerve growth factor (NGF) after subconjunctival injection. Methods: Fluorescent 2.5s NGF was prepared by conjugation with rhodamine succinimidyl ester. Unconjugated rhodamine was removed by extensive dialysis. Twelve mice were anesthetized and the right eye received a single subconjunctival injection of 1.5 µl solution of 0.25% rhodamine-NGF. After survival times of 0.25, 1, 4, or 12 hours, the distribution of fluorescent labeling in eye sections was examined using fluorescence microscopy. Results: Fluorescence was observed in the sclera, choroid, ciliary body and iris of the injected meridian from the injection site to the posterior pole near the optic nerve at 15 minutes. At 1 hour, the sclera and choroid was labeled up to the posterior pole. Fluorescence was not observed at the ciliary body and iris. At 4 hours, the scleral and choroidal fluorescence was limited to the vicinity of the injection site and the brightness was decreased. At 12 hours, the fluorescence labeling was similar to the label distribution at 4 hours in both the area labeled and the brightness of fluorescence. There was no fluorescence in the retina and optic nerve at any time point. Conclusion: Subconjunctival injection is an efficient method to deliver NGF, and possibly other growth factors, to sclera and choroid. However, it does not appear to be practical for delivery of NGF to the retina and optic nerve. None.
Keywords: 423 growth factors/growth factor receptors • 514 pharmacology • 436 injection