EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/115557
124 EW RESIDENTS March 2013 rePlay Cataract M&M rounds online content Nucleofractis almost done F or this column we present another interesting case where we had a complication during surgery. The resident was having some trouble maintaining the anterior chamber during the case, especially when using both hands. At the very end of nucleofractis the phaco needle struck the posterior capsule and a round hole was made. Unfortunately a significant piece of nuclear material remained (about 1/8) but little cortical material remained (Figure 1). We are fortunate to have three master cataract teachers outline how they would move forward from this point in the case and how they would try to prevent phaco strikes of the capsule from occurring. Our experts are Andrew Thliveris, M.D., Ph.D., John Hart Jr., M.D., and Evan (Jake) Waxman, M.D. You can view the video of the case at www.eyeworld.org/replay.php. Thomas Oetting, M.D., Cataract M&M rounds editor Andrew Thliveris, M.D., Ph.D. Chief of ophthalmology, Madison VA, associate professor of ophthalmology, University of Wisconsin, Madison Maintaining chamber In our experience, the most frequent cause of striking the posterior capsule is post-occlusion surge. There are a number of techniques we use to avoid this. First, we make a point of having lens fragments in the bag as long as possible in order to protect the posterior capsule from the tip. Second, we are not proponents of having a second instrument in the eye to hold the capsule back when doing phacoemulsification of the last quadrant. It has been our experience that the capsule can easily track around the instrument and find the phaco tip. This was first suggested to me by Art Weinstein, M.D., Eye Associates of New Mexico, who stressed avoiding the second instrument with inexperienced surgeons or with chamber instability when removing the last quadrant because moving an instrument through a paracentesis port only destabilizes the chamber. Third, we stress working in the anterior center of the eye with the phaco tip while minimizing the movement of the phaco handpiece. This maneuver minimizes the chance of impeding irrigation through the phaco sleeve and maximizes stability by limiting movement of the phaco tip. Last, and key, is the settings of the phaco machine. It is very important to change the settings of the phaco machine for the last quadrant extraction. High vacuum is most useful to secure and remove the first quadrant. Manipulating the last quadrant does not require high vacuum settings (we use 250 mm Hg). What is often overlooked is the aspiration rate. The aspiration rate controls how fast fragments are brought to the phaco tip. Another way of visualizing this, if you build vacuum when securing the last quadrant, is that when you break that vacuum (inducing post-occasional surge), the rate at which the vacuum falls to zero is a function of the aspiration rate. We strongly advocate using a low aspiration rate (20-23) while removing the last quadrant. Removing nuclear fragments with posterior capsular rupture Our approach is to keep the vitreous back and stabilize any fragments to keep them anteriorly. In this case, we would use a non-cohesive OVD and dispense through the posterior capsule hole. Using a cohesive OVD will track forward with any destabilization of the anterior chamber. When I was a resident, Greg Ogawa, M.D. (currently practicing at Eye Associates of New Mexico), used a technique that physically expresses the fragment out of the wound. In the presented case, the nuclear fragment is small, we would surround the fragment with non-cohesive OVD, then secure the fragment with the Simcoe cannula through a paracentesis port without irrigation. The fragment would be deposited at the wound and drawn out of the wound using a spatula. If the quadrant is large, the same procedure would be followed to secure the fragment, using the Simcoe cannula, and once the fragment is brought anteriorly, a spatula through another paracentesis would be used to chop the fragment in half. Again, this is all done under a non-cohesive OVD. Although it is tempting, we try and avoid the use of the phaco tip to secure and emulsify the fragment. Watch this video on your smartphone or iPad using your QR code reader. (Scanner available for free at your app store.) John Hart Jr., M.D. Co-chief, anterior segment surgery, William Beaumont Hospital, and professor of ophthalmology, Oakland University and William Beaumont School of Medicine, Rochester, Mich. Figure 1: A piece of nuclear material remained but little cortical material remained after a phaco needle struck the posterior capsule. Source: Thomas Oetting, M.D.