Glaucoma Surgery: From the Tried and True to the Novel and New.

The surgical options for managing glaucoma have expanded exponentially in recent years. Traditional glaucoma surgery includes trabeculectomy and tube shunt surgery. These procedures drain aqueous into the subconjunctival space, and they are highly effective at lowering intraocular pressure (IOP). Laser suture lysis and releasable sutures allow the surgeon to selectively increase outflow after trabeculectomy, and the ability to titrate IOP postoperatively is an advantage of trabeculectomy over other glaucoma procedures. Mitomycin C and 5-fluorouracil are adjunctive antifibrotic agents that have been shown to improve the success of trabeculectomy, but they also increase the risk of complications such as hypotony maculopathy and bleb-related infections. Tube shunts have been used with increasing frequency as an alternative to trabeculectomy. A silicone tube maintains the patency of the drainage fistula and shunts aqueous humor to an end plate. Devices with larger end plates produce greater IOP reduction, and the presence of a flow restrictor in valved implants serves to reduce the risk of hypotony-related complications. Minimally invasive glaucoma surgery (MIGS) is a newer group of nonbleb-forming procedures performed via an ab interno approach and involves minimal disruption of ocular tissues. Trabecular meshwork/Schlemm's canal MIGS improve aqueous drainage through the conventional outflow system by stenting, dilating, or cutting/stripping the trabecular meshwork and inner wall of Schlemm's canal. Suprachoroidal MIGS create a cyclodialysis and increase uveoscleral flow through a device that connects the anterior chamber and suprachoroidal space. The various MIGS procedures are frequently performed in combination with phacoemulsification in patients with mild to moderate open-angle glaucoma. Minimally invasive glaucoma surgery offers a more favorable safety profile than traditional glaucoma surgery, but MIGS are less effective in lowering IOP. A trade-off exists between safety and efficacy with all currently available glaucoma operations. Surgical innovation in glaucoma has provided surgeons with the opportunity to tailor the selection of a procedure to the individual patient. Multicenter randomized clinical trials have provided valuable information to guide the surgical care of glaucoma patients. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Duke Scholars

Author Leon Walker Herndon Jr. Ophthalmology, Glaucoma