Eyeworld

80 | EYEWORLD | JULY 2021 ATARACT C by Ellen Stodola Editorial Co-Director About the physicians Uday Devgan, MD Clinical Professor of Ophthalmology Jules Stein Eye Institute UCLA School of Medicine Los Angeles, California Thomas Oetting, MD Clinical Professor of Ophthalmology and Visual Sciences Carver College of Medicine University of Iowa Iowa City, Iowa Ronald Yeoh, MD Medical Director Eye & Retina Surgeons Singapore A ccording to Ronald Yeoh, MD, dropped nuclei are one of the more unpleasant complications that can happen during cataract surgery. While uncommon, the consequences of a dropped nucleus are significant, he said, and may require vitreoretinal intervention to retrieve the nucleus from the retina and for associated retinal complications, like retinal detachment and macular edema. "I have certainly encountered cases where the nucleus was 'dropping,' but early recognition of this state of affairs can lead to retrieval of the nucleus before it has dropped to the retina," he said. "Hence the importance of recognizing the scenarios in which it is most likely to happen so that surgeons can avoid the drop entirely or be prepared such that in the event of an impending drop, the nucleus can be retrieved by using a technique like posterior-assisted levitation." Dr. Yeoh noted that nuclei drop when the anterior chamber is pressurized by a phaco tip in the presence of an unsuspected and unde- tected posterior capsule rupture. "Most times, if the posterior capsule ruptures during the phaco chopping or removal of the nucleus stage, the surgeon is aware of it and takes great care to stop the nucleus falling back by using some form of scaffolding or OVD to trap the nucleus before proceeding," Dr. Yeoh said. "It's when the PCR is undetected that nuclei tend to drop." When you do encounter a dropped lens, Thomas Oetting, MD, said that it's important to try to fight the natural instinct to dive after the piece that's fallen. You have to take a few deep breaths, and rather than focus on the personal disappointment of this complication, make sure everything is safe for the patient moving forward. This problem where lens material falls pos- teriorly can occur at the very beginning of the case or it can occur at the very end, Dr. Oetting said, noting a recent trend of a dropped lens at the beginning of surgery during hydrodissec- tion, particularly in patients who have had a lot of intravitreal injections. "This is an interesting problem, and it's a relatively new problem be- cause so many patients are getting intravitreal injections for a variety of conditions," he said. Uday Devgan, MD, agreed that the hydro- dissection step may be when a dropped nucleus would occur. This is a high risk, he said, because you're pressurizing the capsular bag. Conditions that put patients at risk for a dropped nucleus Dr. Oetting elaborated on how intravitreal injections may put patients at increased risk of a dropped nucleus. The intravitreal injections may be placed a bit too anterior and the posterior cap- sule could get injured. These injuries can be quite subtle, he said, and you might not even see them when you do an exam. At the time of hydrodissec- tion, where you're putting a lot of fluid pressure between the lens and capsule, the fluid wave goes around to free the lens from the capsule and it can extend the tear from the injection. A small tear could extend to the point where the nucleus drops immediately, Dr. Oetting said. The best way to handle this, he said, is to be aware of the possibility of this complication from repeated intravitreal injections. "When consenting patients who've had a lot of injec- tions, I always bring this up and say one of the risks of having injections in the vitreous is the potential risk of making cataract surgery a little trickier," he said. Dr. Oetting added that it's important to look prior to surgery to identify any sign that the posterior capsule is injured. When the lens falls posteriorly, it's a shock, he said, but the thing to do at that point is to let it fall. "Patients with posterior polar cataracts have a high incidence of posterior capsule rent for- mation," Dr. Yeoh said. "If the patient waits too long to have the surgery, the nucleus becomes bigger and harder and the risk of nuclear drop is increased because of greater manipulation of the hard nucleus." For this reason, Dr. Yeoh always advocates early surgery for posterior polar cataracts. Additionally, he said that rupturing the pos- terior capsule during chopping and cracking can Handling a dropped nucleus Dropped lens on the retina Source: EyeRounds.org, University of Iowa

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