Morphological Studies on the Rabbits Ciliary Epithelium by Apraclonidine

Baek, Tae Min; Lee, Joo Hwa

Abstract

Apraclonidine is a potent alpha-adrenergic agonist that, like clonidine, is relatively selective for alpha-2 receptors. Apraclonidine has been shown to lower intraocular pressure by diminishing aqueous humor formation. The purpose of this study is to know the morphological changes in the ciliary epithelium by apraclonidine against aqueous formation. In group I, two drops of 1% apraclonidine hydrochloride were instilled on the right eye of the pigmented rabbits and the eyes were enucleated on 1,2.6 and 24 hours after instillation to find out the duration of action of the drug and the tissue response. In group II, one drop was instilled twice daily for seven days on the right eye and the eyes were enucleated on 1, 2 and 5 days after cessation of the instillation observing the cumulative effect of the drug and the tissue response. These eyes were studied with electron mIcroscopIc examiation. As a result, widening of cell membranes(basal infoldings) of the non-pigmented epithelium(NPE) were observed. This change was recovered with time, and seems to be the principal morphological changes of apraclonidine against aqueous formation in the ciliary body. In group II, the cellular changes were minimal except for well developed rough endoplasmic reticulum representing resumed secretary function of the cell.