Cyclocryotherapy in neovascular glaucoma and non-neovascular glaucoma

Abstract

There are conflicting reports on the value of cyclocryotherapy and it seems that the success rate is depending on glaucoma conditions, the period of follow-up and the technique. This retrospective study was carried out to assess the efficacy and complication rate of cyclocryosurgery for advanced glaucoma with and without neovascularization. We induced 76 eyes of 75 patients with inadequately controlled glaucoma, which underwent cyclocryotherapy during the period of 1993 and 1996 (treatment time 60 seconds with -80 degrees C, 6-12 applications (mean 9.8 +/- 2.3), 180-360 degree (median 270 degree), diameter of the probe tip 2.5 mm, 1-2 mm distance from the limbus). Depending on the etiology we distinguished between neovascular (NVG) and non-neovascular glaucoma (nNVG). Pre- and postoperative data from all patients were studied retrospectively, for follow-up after 12-36 months patients were examined. Intraocular pressure (IOP) decreased in all patients from 44.7 +/- 12.6 mm Hg preoperatively to 15.6 +/- 6.5 mm Hg postoperatively after a follow-up of 12-36 months. In 88.2% IOP was lowered to < or = 25 mm Hg. NVG showed a mean IOP reduction from 49.1 +/- 12.5 mm Hg before cyclocryotherapy to 15.6 +/- 5.0 mm Hg at follow-up. In the nNVG group IOP was 40.5 +/- 11.3 mm Hg and 15.7 +/- 7.6 mm Hg after cyclocryotherapy. Pressure was controlled (< or = 25 mm Hg) for 83.8% of NVG and 92.3% of nNVG. A cyclocryotherapy-induced intense inflammation was seen more frequent in NVG (43.2%) than in nNVG (17.9%). 2 patients with NVG and 3 with nNVG developed phthisis postoperatively (total 6.7%). Cyclocryosurgery is an effective method to reduce IOP in advanced, refractory glaucoma, when other methods have failed. The risk/success rate seems to be acceptable.