Cyclocryotherapy (CCT) is a procedure that employs temperatures as low as -112°F (-80°C) to destroy the ciliary body, an organ in the anterior chamber of the eye behind the iris, which produces aqueous fluid. A certain amount of fluid is required to maintain the integrity of the eye, but an increase in intraocular fluid leads to an elevation in intraocular pressure (IOP); elevated IOP is a major cause of glaucoma. Ablation, or destruction, of part of the ciliary body lowers the IOP by decreasing the fluid or aqueous humor within the eye and thus helping to control glaucoma. The main purpose of CCT is to treat uncontrolled or refractory glaucoma. It is also used to reduce ocular pain in some patients with end-stage glaucoma.

From http://www.enotes.com/surgery-encyclopedia/cyclocryotherapy