The most important limiting factor in glued IOL fixation is the limited amount of haptic externalized in large eyes. Inadequate haptic tuck into the scleral pockets can lead to unstable IOL fixation. Anterior sclerotomy is often performed for large eyes, shifting the IOL plane anteriorly to allow less distance to be traversed by the haptics, thereby facilitating greater haptic length exteriorization. In this endeavor, the iris is often damaged during the procedure of creating an anterior sclerotomy. Performing a peripheral iridectomy at the proposed site of an anterior sclerotomy can prevent this complication because the needle does not tend to hit the base of the iris as during anterior sclerotomy.
The video demonstrates the technique of performing a peripheral iridectomy assisted by the vitrectomy probe. After performing a limited anterior vitrectomy, the cutting rate of the vitrector is brought down to 20 cuts per minute with a moderate amount of vacuum. Peripheral iridectomy is then performed followed by anterior sclerotomy. Performing a peripheral iridectomy ensures smooth passage for the needle and glued IOL forceps that do not tend to damage the base of the iris tissue. Lensectomy with vitrectomy is then performed, followed by the introduction of a three-piece IOL, haptic externalization, haptic tuck and fibrin glue application to seal the flaps.