Diode laser transscleral cyclophotocoagulation as primary surgical treatment for medically uncontrolled chronic angle closure glaucoma: long-term clinical outcomes

Abstract

Purpose: To evaluate the long-term efficacy and safety of diode laser transscleral cyclophotocoagulation as primary surgical treatment of medically uncontrolled chronic angle closure glaucoma.

Patients and methods: Thirteen eyes of 13 Chinese patients with medically uncontrolled chronic angle closure glaucoma were treated with diode laser transscleral cyclophotocoagulation between February 2000 and May 2001, and followed up for over 18 months. Post-treatment anti-glaucoma medications were adjusted according to intraocular pressure. If intraocular pressure remained above 21 mm Hg despite medications for more than 4 weeks after cyclophotocoagulation, the procedure was repeated.

Results: Mean follow-up +/- SD was 26.5 +/- 4.2 months. Two eyes required repeat cyclophotocoagulation at 6 weeks. Rate of relative success, defined as maintaining an intraocular pressure of 21 mm Hg or below with or without medications, was 92.3% (12 of 13 eyes). Rate of absolute success, defined as maintaining an intraocular pressure of 21 mm Hg or below without medications, was 0% (0 of 13 eyes). Mean +/- SD intraocular pressure was reduced from 36.4 +/- 12.6 mm Hg pre-operatively, to 18.7 +/- 12.2 mm Hg at final follow-up (P = 0.003, paired t test). The mean +/- SD number of intraocular pressure-lowering eye drops was reduced from 2.0 +/- 0.8 pre-operatively, to the lowest point of 0.5 +/- 0.8 at 12 months, and then gradually increased to 2.1 +/- 0.9 at final follow-up. The visual acuity improved after treatment in 2 of 13 eyes (15.4%), remained unchanged in 6 of 13 eyes (46.2%) and deteriorated in 5 of 13 eyes (38.5%). No major complications were encountered.

Conclusion: Diode laser cyclophotocoagulation appeared to be an effective and safe primary surgical treatment of medically uncontrolled chronic angle closure glaucoma, with intraocular pressure-lowering effect persisting for up to two years.