[Experimental glaucoma model in the rat with laser trabecular photocoagulation after intracameral injection of India ink].

ABSTRACT

We tried to create an experimental glaucoma which is simple and highly reproducible in rodents. India ink was injected into the anterior chamber with a 30-gauge needle. The carbon particles were trapped in the chamber angle and formed a black band along the corneal limbus one week later. This area was then photocoagulated anteroposteriorly with an argon laser. Photocoagulation was repeated until the intraocular pressure was elevated to 25 mmHg or more by pneumotonometry performed at a one-week interval. The above procedure was applied to one eye of 7 rats with the fellow eye serving as control. Chronic elevation of intraocular pressure was obtained in all the 7 treated eyes. The eyes were then enucleated and examined by light microscopy. Carbon particles were phagocytosed by macrophages in the intertrabecular spaces. Peripheral anterior synechias were also present. The optic nerve-head showed remarkable decrease in nerve fibers and cavernous degeneration suggestive of glaucomatous optic nerve damage. This experimental model promises to be of value in further studies of glaucomatous optic nerve damage.