Delayed Response to Argon Laser Trabeculoplasty in Monkeys: Morphological and Morphometric Analysis

Shlomo Melamed*, Jean Pei, David L. Epstein

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


In eight cynomolgus monkeys we performed argon laser trabeculoplasty and evaluated morphological changes in the trabecular meshwork (TM). Four weeks after laser treatment, the treated spots were detected as regions of flattened and collapsed beams covered by a cellular sheet extending from the corneal endothelium. The inner wall of Schlemm's canal beneath these regions was flat, with no vacuoles despite fixation with intraocular pressure maintained at 15 mm Hg. Adjacent nonlasered spots had wide open intertrabecular spaces with herniations of juxtacanalicular TM and of inner wall endothelium into and across the lumen of Schlemm's canal. The herniations contained chronic inflammatory cells and large vacuoles. Statistical morphometric analysis in three monkeys established that these herniations were significantly wider, more numerous, and contained more vacuoles than did control eyes. Our findings suggest that a biologic process is involved in these reactions to argon laser trabeculoplasty. Scarring is seen to obliterate TM in spots treated by the laser, and this apparently causes the flow of the aqueous humor to be diverted through adjacent nonlasered regions that become structurally altered to compensate for this overload of flow.

Original languageEnglish
Pages (from-to)1078-1083
Number of pages6
JournalArchives of Ophthalmology
Issue number7
StatePublished - Jul 1986
Externally publishedYes


Dive into the research topics of 'Delayed Response to Argon Laser Trabeculoplasty in Monkeys: Morphological and Morphometric Analysis'. Together they form a unique fingerprint.

Cite this