Ultrasound biomicroscopic analysis of the human ciliary body after 1 and 2% pilocarpine instillation

We examined ciliary body thickness (CBT) of 11 human eyes after 1% followed by 2% pilocarpine instillation using ultrasound biomicroscopy, The examina tion revealed that CBT decreased in 2 eyes after 1% pilocarpine treatment b ut increased after 2% pilocarpine. In the eyes with decreased CBT by 1% pil ocarpine, the pretreatment ciliary bodies were thicker and the changing rat e of CBT induced by 2% pilocarpine, although not decreased, was also smalle r than that in CBT-increased eyes. These findings showed that the ciliary b ody was under relatively strong stimulus of endogenous acetylcholine and ha s subsensitivity to both 1 and 2% pilocarpine in CBT-decreased eyes. Config urative changes in CBT-decreased eyes may be explained by the localization of different muscarinic receptor subtypes in different portions of the cili ary muscle. Copyright (C) 2000 S. Karger AG, Basel.