25-gauge vitrectomy scrutinized by task force

Key Points

Richard S. Kaiser, MD, who reported the findings of the Micro-Surgical Safety Task Force at retina subspecialty day at the annual meeting of the American Academy of Ophthalmology (AAO), focused on the increased incidence of endophthalmitis following small-gauge vitrectomy and noted that the 25-gauge procedure has a risk of infection that is 12.4 times greater compared with the 20-gauge procedure.

In light of this substantial increase, the task force, composed of experienced retina surgeons, undertook the task of analyzing the potential complications associated with sutureless vitrectomy and disseminating guidelines to reduce the rate of endophthalmitis associated with 25-gauge vitrectomy.

"There was a very distinct disparity in the incidence of endophthalmitis between the two groups, with a 12.4 times greater risk in the 25-gauge group," said Dr. Kaiser, associate surgeon, retina service, Wills Eye Institute, and assistant clinical professor, Thomas Jefferson University, Philadelphia.

The important clinical question, he said, is that if an increased risk of endophthalmitis is associated with sutureless vitrectomy, what can be done to lower the incidence?

"We are obligated as surgeons to try to perfect our techniques to make the surgeries as safe as possible for our patients," Dr. Kaiser said. "With that goal in mind, we organized the Micro-Surgical Safety Task Force to dissect the procedures and suggest possible ways to improve the surgery."

Possible surgical steps

Regarding the preoperative ocular preparation, the task force members agreed that the use of povidone-iodine is essential to the surgery. The lidocaine gel, however, should be rinsed off the ocular surface to allow direct contact of povidone-iodine with the conjunctiva and maximize its effect, they suggested. Another consideration was that povidone-iodine should be applied to the conjunctiva immediately before the eye is entered, according to Dr. Kaiser.

Intraoperative alterations

Regarding intraoperative alterations to the surgical procedures, all members of the task force agreed on the following:

"In all the cases of endophthalmitis in the Wills series and most of those in the literature, eyes were fluid-filled at the end of the cases," Dr. Kaiser said. "An air-fluid exchange might provide a more uniform IOP postoperatively and will eliminate the influx and efflux of fluid that might occur in a fluid-filled eye."

"Placing a light pipe into the trocar allows vitreous to be mechanically pushed back into the eye," Dr. Kaiser said. "The trocar can be gradually brought up the shaft of the light pipe and the wound can be massaged. This may help the vitreous to retract." An alternative approach, he said, is to slide the trocar up the light pipe and introduce a muscle hook to avoid the vitreous being drawn up by cotton fibers on the cotton tip.