Experimental Ocular Hypertension Research Articles

A chemically induced experimental ocular hypertension for evaluating drug effects in albino rabbits.

A test model is described for production of experimental ocular hypertension in albino rabbits. The procedure employs applanation tonometry for intraocular pressure (IOP) measurement; is simple in design and requires little time to perform. Eight pharmacologic classes of drugs were evaluated using this procedure. Good correlation is described between drugs topically effective in clinical treatment of glaucoma and those lowering IOP in this test system. The described method was most sensitive for the adrenergic stimulants of both α and β variety. Physostigmine (cholinesterase inhibitor) effectively lowered IOP as did the direct-acting cholinergic stimulant carbachol. A concentration-response relationship with pilocarpine, however, was not observed. Ganglionic blocking agents effectively lowered IOP and confirm the involvement of a neuroreflex mechanism involved in production of “irritation-induced” hypertension. Adrenergic blocking agents, muscarinic cholinergic blocking agents, and local anesthetics were ineffective ocular hypotensive agents in this test model.

The effect of citral on intraocular dynamics in monkeys.

<h3>Introduction</h3> Experimental ocular hypertension can be induced by production of a permanent condition of vascular stasis and congestion (ligating the vortex or ciliary veins), or by blockage of the circulation of the intraocular fluid after injecting nondiffusible oils, or by exciting inflammatory and proliferative reactions in the anterior chamber (Duke-Elder, 1940).¹More recently the discovery of sanguinarine poisoning as the cause of epidemic dropsy and its accompanying raised intraocular tension gave rise to new possibilities for studying glaucoma in the laboratory. Hakim²(1954), and Leach and Lloyd^3,4(1955 and 1956), produced a raised intraocular pressure by administering argemone oil, which consists of sanguinarine and other allied alkaloids. While Leach and Lloyd were working on sanguinarine poisoning, they found that the control monkeys, which were getting an orange twice a week along with a stock diet, showed histopathological changes in the trabecular meshwork similar to that of the