Objective: This document describes cyclophotocoagulation procedures for glaucoma and examines the evidence to answer key questions about patient selection, and efficacy of transscleral and endoscopic techniques.
Methods: A literature search conducted for the years 1968 to 2000 retrieved 130 citations. The author reviewed 34 of these articles and selected 19 for the panel methodologist to review and rate according to the strength of evidence. A Level I rating is assigned to properly conducted, well-designed, randomized clinical trials; a Level II rating is assigned to well-designed cohort and case-control studies; and a Level III rating is assigned to case series and poorly designed prospective and retrospective studies, including case-control studies.
Results: The predominant problem with all studies on cyclophotocoagulation is the lack of a uniform definition of success, which makes comparisons difficult. One randomized controlled trial (Level I evidence) compared the efficacy of transscleral cyclophotocoagulation with noncontact Nd:YAG and semiconductor diode laser. It found no significant difference between the two, although a significant problem was the variability allowed with laser parameters. Most of the literature consists of noncomparative case series that provide evidence that is limited and often not convincing.
Conclusion: Cyclophotocoagulation is indicated for patients with refractory glaucoma who have failed trabeculectomy or tube shunt procedures, patients with minimal useful vision and elevated intraocular pressure, and patients who have no visual potential and need pain relief (based on Level III evidence). It may be useful for patients whose general medical condition precludes invasive surgery or who refuse more aggressive surgery (i.e., filter or tube). It is also useful in emergent situations, such as the acute onset of neovascular glaucoma. There is insufficient evidence to definitively compare the relative efficacy of the cyclophotocoagulation procedures for glaucoma. It is the panel's opinion, however, that semiconductor diode systems appear to possess the best combination of effectiveness (based on Level III evidence), portability, expense, and ease of use at this time.