The Microsurgical Safety Task Force: evolving guidelines for minimizing the risk of endophthalmitis associated with microincisional vitrectomy surgery.

The Microsurgical Safety Task Force: Evolving Guidelines for Minimizing the Risk of Endophthalmitis Associated With Microincisional Vitrectomy Surgery V itrectomy surgery is performed 250,000 times per year in the United States and 500,000 times per year world-wide for a variety of vitreoretinal pathologic conditions. Traditionally, vitrectomy surgery has been performed with 20-gauge (20-G) instrumentation, first by creating conjunctival peritomies and then constructing 3 20-G scleral incisions through the pars plana to allow access to the vitreous cavity. The conjunctival peritomies and three sclerotomy sites are closed with sutures at the conclusion of the surgery. In contrast to 20-G surgery, 25-gauge (25-G) or 23-gauge (23-G) vitrectomy is initiated by placing 3 cannulae through the conjunctiva, sclera, and pars plana. At the conclusion of the procedure, the cannulae are removed, and because of the smaller incision size, the wounds may self-seal without sutures. The development of a 20-G microincisional cannulae system also is now being evaluated. Overall, 25-G and 23-G surgery avoids the need for conjunctival peritomies and their subsequent closure with sutures, avoids the need for sclerotomy sutures, and permits the use of smaller wounds. This, in turn, has the potential to shorten operative times, improve early postoperative visual outcomes, decrease postoperative discomfort, and hasten postoperative recovery. As with most evolutionary routes, the transition to minimally invasive vitrectomy surgery has not been an entirely smooth one. With the new techniques, a collection of new instruments and refinements in the surgical technique have arrived. Today, the popularity of 23-G and 25-G vitrectomy surgery is at its highest level yet and is still rising. During the past 5 years, there has been a rapid adaptation of microincisional vitrectomy and its usage continues to rise.1,2 In 2008, 50% of vitreous surgery incorporated the microincisional technique. According to a survey conducted by the American Society of Retina Specialists, 70% of U.S. surgeons used 25-G technology in 2007.1 In contrast, just 3 years earlier, 70% of surgeons had claimed to have never used the technique.2 The trend of increased usage and expanding indications for small-gauge vitrectomy has been associated with reports of an increased rate of postvitrectomy complications, including early postoperative hypotony, choroidal hemorrhage, and endophthalmitis.3–11 Although all postoperative complications are potentially vision threatening, endophthalmitis is the most dreaded and severe complication of any intraocular procedure and may result in severe vision loss or blindness. Because of several reports of an increased incidence of endophthalmitis with microincisional vitrectomy compared with sutured vitrectomy,7–9 a Microsurgery Safety Task Force was convened; consensus was sought among a panel of vitreoretinal surgeons experienced with both 20-G and small-gauge pars plana vitrectomy (PPV). Objective evidence was sought for all guidelines, but consensus was accepted when evidence remains incomplete. In the absence of either evidence or consensus, this study identifies the outstanding issues in need of further investigation.