EyeWorld Asia-Pacific June 2011 Issue

June 2011 10 EW FEATURE of a clear crystalline lens, a cataract lens, a posterior chamber IOL, an anterior chamber IOL, or even aphakia. In each setting the surgeon can be faced with a dilemma. When patients present with Fuchs’ dystrophy or bullous keratopathy and a posterior chamber IOL is in place, Dr. Terry advised surgeons to “go ahead with the DSAEK; there’s no therapeutic dilemma.” If the patient is phakic, however, and the cataract is visually disturbing, then he would proceed with a combined DSEK/phaco procedure. “Our published results with the new triple procedure in 225 consecutive eyes yielded a low 1.8% dislocation rate and 0% primary graft failure rate, so doing this combined procedure is safe,” he said. “Conversely, if the patient only has mild Fuchs’ and the visual loss is almost entirely from the cataract, there may be no need to perform a transplant at all, and a careful phaco/IOL should be done.” Sometimes, patients present with endothelial dystrophy “and the corneal disease is accounting for a more significant decrease in visual acuity than the cataract”, Dr. Lane said. Patients with Fuchs’ and frank corneal edema are destined for a corneal transplant, but age should determine if it becomes a combined procedure with phaco, he said. Forty-year-olds will not have as visually significant a cataract as 60-year-olds. “But if the surgery itself is likely to cause a cataract to develop, you have to weigh if it’s worthwhile to remove the lens at the same time as the corneal procedure,” he said. In general, his rule of thumb is when the endothelial disease is worse than the cataract, combining procedures makes sense, but when the cataract is worse and there is no frank corneal edema on clinical exam and no history of morning edema, “see if the corneal endothelium can withstand the trauma of the surgery,” he said. Certainly a thorough discussion of the potential for a second procedure must be had before sequential surgery is entertained. He also recommended staggered surgery, waiting until the worst eye has vision equal to the better eye before operating on the better eye. “If there is more cataract than endothelial disease, I’ll operate sequentially, but if there’s more corneal disease than cataract, I’ll operate concurrently. The reasoning is that after endothelial keratoplasty, I don’t want to have to go back into the eye later and potentially traumatize the graft. I don’t want to risk damaging the graft,” he said. Because diagnostic tools have been unable to help clinicians determine what percentage of the visual disability is from corneal disease versus cataract, coupled with retinal disease pathologies in some patients, “it’s very difficult to determine what’s at the heart of the visual problem,” Dr. Yoo said. “To some degree, we’re relying upon our own acumen to make the correct diagnosis. There’s a need for better diagnostics to sort it out.” Having a complete patient history can help, she said, adding she personally has a lower threshold for putting in an implant than when the patient does not have concurrent corneal disease. Corneal transplant patients will require long-term steroid use, which hastens the progression of cataract, so removing even early cataracts makes sense, Dr. Yoo said. “You know you’re going to lose endothelial cells, and that usually sways me toward removing the cataract at the time of corneal transplant,” she said. “The opposite is a trickier algorithm. When you’ve got visually significant cataract and corneal guttata without edema, it’s more difficult to think about taking out the cataract alone.” If a patient has a lower cell count (under 1,000 mm 2 ) and a pachymetry level higher than 680 microns, “I lean toward a combined procedure,” she said. When pachymetry is between 640 and 680 microns, “I counsel them about their risk of corneal decompensation being higher than the average person, but I’m more willing to perform cataract surgery alone.” She added that surgical techniques can alter outcomes as well—soft shell techniques help preserve more cells, and newer phaco technology that reduces the amount of energy and time also helps preserve more cells. Dr. Terry said he looks at the patient’s age—if the patient has a minimal cataract but significant Fuchs’ and is younger than 50 years old, “leave the lens in place and consider just performing DSAEK,” he said. “Under the age of 50 the patient still has some accommodation left in the lens, and the data shows that these younger lenses are less likely to develop cataract changes post-op.” Dr Terry was quick to add that “phakic DSAEK surgery is more difficult to perform and the 50-year mark is not set in stone, but is a general threshold.” Eyes with corneal edema and an anterior chamber IOL in place can present the greatest surgical dilemma. “Replacing the anterior chamber IOL with a sewn-in posterior chamber IOL allows the DSAEK surgery to be much easier, but can be a very extended surgery,” Dr. Terry said. “On the other hand, leaving the anterior chamber IOL in place can make DSAEK very difficult due to the crowded chamber and the unicameral eye,” he said. “We decide what course to take based on the stability of the AC IOL. If the IOL has been in place for many years and the edema only occurred recently, we will leave the lens in place and just do the DSAEK. If the anterior chamber IOL was recently placed and followed quickly by persistent edema, it usually means it is unstable and needs to be replaced. Of course, stability of the lens is always mechanically verified at the time of surgery.” Another co-morbidity combination that’s not discussed often is cataracts in the presence of anterior basement membrane corneal dystrophy, Dr. Lane said. “In these patients, the irregular surface means you’ll get an error in your IOL calculations,” he said. “You need to perform a sequential procedure, corneal scraping and letting the cornea heal smoothly, then the measurements and cataract surgery. Scraping first will ensure you’re getting a pure, pristine surface for accurate IOL measurements.” Future trends As diagnostics improve and treatment options for concomitant diseases are expanded, more surgeons are likely to incorporate surgical treatments earlier in the course of a disease. For instance, Dr. Terry noted the improved optics and large decrease in recovery time has moved him to perform DSEK earlier in the disease and in younger patients, compared to full- thickness transplants. “For PK, the average age and vision of someone undergoing surgery in my practice 20 years ago when they had Fuchs’ was 78 years old and 20/100 [6/30] vision. With DSAEK, it is now similar to simple cataract surgery cases at 65 years old with 20/60 [6/18] vision,” he said. EW Editors’ note: Dr. Donnenfeld has financial interests with Alcon (Fort Worth, Texas, USA) and Glaukos. The other physicians interviewed have no financial interests related to their comments. Contact information Devgan: 800-337-1969, devgan@gmail.com Donnenfeld: 16-766-2519, eddoph@aol.com Lane: 651-275-3000, sslane@associatedeyecare.com Terry: 503-413-6223, MTerry@DeversEye.org Yoo: 305-326-6322, syoo@med.miami.edu Co-morbidities continued from page 8