Purpose of review: This article reviews recent studies evaluating the efficacy and safety of ab externo and ab interno suprachoroidal shunts designed to augment uveoscleral outflow in patients with open angle glaucoma.
Recent findings: The Gold Shunt and STARflo are placed into the suprachoroidal space via an ab externo approach, while the CyPass Micro-Stent and iStent Supra are inserted ab interno through a clear corneal incision. A small randomized clinical trial suggested similar efficacy among two different models of the Gold Shunt and the Ahmed glaucoma valve. The pivotal multicenter, randomized COMPASS trial showed that the CyPass Micro-Stent combined with cataract surgery is more effective than cataract surgery alone through 2 years. Study results suggest a favorable safety profile for each suprachoroidal device and intraocular pressure-lowering to the mid-to-high teens with an associated reduction in medication burden. Given the relative novelty of these procedures, it is currently unknown whether fibroblastic proliferation within the suprachoroidal space may limit their long-term success.
Summary: Renewed interest in the suprachoroidal space has led to the development of new biocompatible glaucoma implants. Ab interno devices are easily combined with cataract surgery and preserve conjunctiva for future incisional glaucoma surgery. Additional data regarding the long-term efficacy and late complications of suprachoroidal shunts are needed.