The ultrastructural features of laser trabeculopuncture and cyclodialysis. Problems related to successful treatment of chronic simple glaucoma

Abstract

Microexplosions induced by a Q-switched Nd:glass laser working above optical breakdown power density levels are able to destroy the inner wall of Schlemm's canal and to tear open both the supraciliary and suprachoroidal space. Furthermore, the ciliary muscles bundles may be disrupted, becoming subsequently permeable to the aqueous and thus also acting as a new outflow route. However, whereas breaks of the inner wall of Schlemm's canals are sealed in the monkey by the activity of endothelial cells forming a new Descemet membrane over the impact site, the supraciliary and suprachoroidal spaces remain open over an observation period of up to 480 days. Perfusion experiments with a HgS tracer substance have shown that these newly created, potential outflow routes may be considered as real additional filtration areas.