Endoscopic and transscleral cyclophotocoagulation for the treatment of refractory glaucoma

Purpose: Cyclophotocoagulation (CPC) is traditionally used in cases of glaucoma that are refractory to medical and surgical therapy. The goal of this review is to provide an update on the methods, efficacy, complications, indications, and histopathology of transscleral and endoscopic CPC. Methods: A literature review was conducted for transscleral and endoscopic CPC. Relevant studies were included for evaluation of the procedures. Results: For transscleral CPC (TCP), there is a wide range of success rates reported in the literature, depending on energy settings, follow-up period, and definitions of success. Repeat TCP is often required. Serious complications have included significant vision loss, hypotony, and phthisis. TCP has mostly been performed in very severe forms of glaucoma, in eyes with limited visual potential, or after filtration surgery has failed, although more recently TCP has been used as a primary surgery in eyes with good visual potential. There are more limited published results on endoscopic CPC (ECP), which have demonstrated overall good success. Complication rates are relatively low with ECP, however, large studies with long-term follow-up are lacking. ECP has also been used in difficult, refractory cases, but often used earlier when combined with cataract surgery. Conclusions: Both TCP and ECP are effective surgeries with potential for serious complications. Recent studies suggest they may be used increasingly as the primary surgery for various stages of glaucoma.