Effect of antiglaucomatous eye drops on corneal endothelium

Abstract

First choice therapy for reducing the intraocular pressure in context of glaucoma remains the applications of eye drops. Longterm exposure to topical therapy can clearly have an impact on the ocular surface, but as the medications penetrate through the cornea and are present in humour aqueous, also on all other layers of cornea, including corneal endothelium. In general, none of the medications from the standard pharmacological groups influences significantly an otherwise healthy corneal endothelium in an eye with glaucoma or ocular hypertension – be it in terms of central corneal thickness, be it in terms of endothelial cell density and morphology, be it for beta blockers, carbonic anhydrase inhibitors, pilocarpine, alpha2 agonists or prostaglandin analogues. The situation changes in diseased corneas, such as in Fuchs endothelial dystrophy, where topically applied carbonic anhydrase inhibitors can lead to increase in corneal thickness. Benzalkonium chloride has been proven toxic for corneal endothelial cells in vitro. However, in the daily practice and under real life circumstances, it is from the specific point of view on the corneal endothelium still not clear whether using non‐preserved topical glaucoma medications is an absolute imperative. One separate topic here is also a group of Rho‐kinase inhibiting topical medications. Apart from new mechanisms of action for reducing the intraocular pressure, this group of medications has also a direct influence on the corneal structures – from cornea verticillata on the epithelium corneal level, to mobilizing peripheral endothelial corneal cells as a possible therapeutic path for Fuchs endothelial dystrophy. One part of the lecture will address also these issues.