Eyeworld

EW CATARACT/IOL 27 Nuclear remnant surfaces 3 years after cataract surgery in corneal transplant patient E ven if phacoemulsification appears uneventful, don't forget that a nuclear frag- ment could have been left behind, especially in cer- tain types of patients. In addition, the retained fragment could go un- noticed for years. These tips come from a study published online in January in the Journal of Cataract & Refractive Sur- gery, which found a retained nuclear fragment 3 years after uneventful cataract surgery. It was discovered in a patient during a Descemet's strip- ping automated endothelial kerato- plasty (DSAEK) procedure to alleviate pseudophakic bullous ker- atopathy. "Various studies have reported corneal edema from retained nuclear fragments," reported lead study au- thor Mark D. Mifflin, M.D., oph- thalmology and visual sciences de- partment, John A. Moran Eye Center, University of Utah, Salt Lake City. "Our case is unique because the patient presented approximately 3 years after phacoemulsification and the lens fragment was not discov- ered until it appeared during DSAEK surgery." What happened When an 82-year-old man presented with persistent corneal edema in the right eye, he was evaluated and found to have had cataract surgery 3 years earlier. "The patient reported a 2- to 3-month history of markedly de- creased vision in the right eye ac- companied by foreign-body sensation and photophobia," Dr. Mifflin noted. "Prior to referral, he had been treated empirically for pre- sumed herpes simplex keratitis by his community ophthalmologist." Best corrected visual acuity was 20/400 in the right eye, with IOP at 15 mm Hg, and pachymetry measur- ing 897 microns. "Slit lamp examination of the right eye revealed central corneal edema with stromal folds and micro- cystic changes," Dr. Mifflin noted. "Dilated fundoscopic examination of the right eye was partially ob- scured due to corneal edema; how- ever, no retinal pathology was noted. A large amount of optic nerve head cupping was noted, with a cup- to-disc ratio of 0.7 in the right eye and 0.8 in the left eye. The patient was scheduled to have DSAEK for pseudophakic bullous keratopathy and was also referred to a glaucoma specialist for evaluation and man- agement." A surgeon noticed the retained fragment during DSAEK. "When the irrigation/aspiration (I/A) handpiece was inserted into the anterior cham- ber to remove the ophthalmic visco- surgical device, it encountered a small dense nuclear lens fragment," Dr. Mifflin noted. "The retained lens fragment was completely removed using the I/A handpiece and a sec- ond instrument through the side port. The DSAEK procedure was then continued, and an 8.5 mm graft was placed and positioned without com- plication." Later, a pathology report indi- cated that the patient did experience severe endothelial cell loss and that Descemet's membrane experienced pseudophakic bullous keratopathy. The patient recovered uncor- rected distance vision to 20/50 at 2 months, improving to 20/40 by the 4-month follow-up. The case should have an impres- sion on surgeons' views about re- tained lens fragments. Already research has suggested that small lens fragments can become "con- cealed in the angle, in iris crypts, or posterior to the iris," Dr. Mifflin noted. They are more likely to occur in myopic patients who have deep anterior chambers and long axial lengths, providing more space for nuclear fragments to get lost and ei- ther remain in the posterior cham- by Matt Young EyeWorld Contributing Editor Physicians must be aware of lurking nuclear fragments Vitrectomy continued from page 26 Our goal is to prevent collateral damage. We don't want to sacrifice endothelium, so any maneuver needs to be with a good viscoelastic sandwich protecting the endothe- lium. We don't want to sacrifice iris integrity or eat up the capsule. The worse thing is to have the break in the posterior capsule and the ante- rior capsule because then we may not be able to have a stable implant without sewing it in or putting an anterior chamber lens. If we can maintain an appropriate anterior capsulorhexis, we have the option of optic capturing. I would only put a lens in a bag if I converted its tear to a true capsulorhexis. Otherwise, I would put a three-piece lens in the sulcus and capture the optic through the intact capsulorhexis. The right incision I advocate that for surgeons who know how, they should do a proper pars plana incision for a vitrectomy where the irrigation is always going to be through the anterior paracen- tesis. The posterior incision is more efficient and more effective when one understands how to make a proper pars plana incision safely. Do not sweep the incision as this causes vitreous traction. If there's already vitreous out of the incision, the surgeon will want to amputate it, which is much easier to do from a pars plana approach. However, if the surgeon is going to do an anterior approach, he or she has to be prepared for vitreous pres- entation since that will leave the lower pressure anteriorly. In this ap- proach, do not use the main cataract incision because it won't be water- tight. It will allow vitreous to flow around the bare vitrector needle, so a new paracentesis that's appropriate for the vitrector, whether that's 20- gauge or 23-gauge, is needed. When making a new incision for the bare vitrector, always go bi- axial, whether the approach is ante- rior or posterior; you still have a machine where the sleeve is on the vitrector. Separate the irrigation from the vitrector sleeve so as to en- courage vitreous posteriorly and not displace the vitreous with fluid, which happens if the coaxial ap- proach is taken. Finally, in order to make a su- tureless incision with a 23-gauge in the pars plana, the surgeon has to know how to go radial to the limbus and then perpendicular to the sclera in order to enter. This should be done when the eye is firm but not with open incisions because of the pressure that it takes to put the 23- gauge in. The main issue is to be sure that the surgeon doesn't leave vitreous anterior to the posterior capsule so that there's no post-op vitreous trac- tion and to be sure that incisions seal properly. Bring the pupil down and make sure it's round, and finish with a bit of Triesence or washed ke- nalog without preservatives so there's no further vitreous present. In addition, the kenalog or Triesence is therapeutic and reduces inflam- mation. Keep in mind that when there's a breach at the anterior hyaloid, there's a higher chance of endoph- thalmitis, so I use intracameral Vigamox (moxifloxacin, Alcon), al- though that's an off-label use in rou- tine cases. When the hyaloid is broken, the surgeon should consider a single prophylactic dose of oral moxifloxacin, which gives a good MIC into the vitreous. Follow these patients very closely to prevent pres- sure spikes. We want to have a good peripheral retina exam within the first couple of weeks after surgery to be sure there are no holes or tears that need attention. Plenty of anti- inflammatory treatment, both steroidal and non-steroidal, is appro- priate since the incidence of CME is much higher, and that should be continued for longer than normal. We can have wonderful results. Disclosure to patients is important because their risk of retinal tears or detachments, CME, or glaucoma may be greater, so they need to be aware of the signs and symptoms so that they can protect themselves in the future. EW Editors' note: Dr. Arbisser has a finan- cial interest with Alcon. Contact information Arbisser: 563-323-2020, drlisa@arbisser.com continued on page 28 May 2011

• Cover