EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/78719
February 2012 EW CATARACT 43 said William B. Trattler, M.D., director of cornea, Center for Excellence in Eye Care, Miami. "If someone has mild forme fruste keratoconus, a toric IOL can be effective. But if the patient has significant keratoconus, a toric lens won't help. So why not consider cataract surgery with a monofocal IOL, target for –2.00 to –2.50, and then a few months after surgery, consider CXL with the goal of im- proving the corneal shape and BSCVA?" he said. Base the decision of CXL on the patient's age and progression of the cone, said Daniel B. Goldberg, M.D., clinical associate professor of ophthalmology, Drexel College of Medicine, Philadelphia. Patients in their 50s who haven't needed a corneal transplant likely have stable, or at least non-progressing, kerato- conus, he said. "You're going to get very unpre- dictable results with a toric lens un- less the cone meets certain criteria. A minority of cases will fall into that group," Dr. Goldberg said. He will use toric lenses in selected cases where the astigmatism centrally is more orthogonal. Monofocal and CXL? Dr. Trattler said he recommends patients with both cataract and keratoconus undergo the cataract surgery first, as "eliminating the cataract provides improved vision for the patient, and post-operatively we can determine the degree of loss of BSCVA" from keratoconus. "Pa- tients can undergo crosslinking after phaco with the goal of improving corneal shape and improving best spectacle-corrected vision," he said. Patients should be counseled that crosslinking will induce a hyperopic shift, he said, and is likely to im- prove BSCVA. Dr. Safran disagreed with that proposed timing. "If I were to crosslink a cataract patient, I'd do it before cataract surgery because of the potential changes in curvature due to the pro- cedure and effect it could have on the implant chosen," he said. "Then I'd use a toric to clean up the resid- ual astigmatism if the patient were not gas-permeable CL dependent and the axis was still clear and con- sistent." Dr. Trattler—who is an investi- gator for the CXL-USA group—said both corneal shape and refractive changes can continue for more than a year after CXL, so determining the right toric IOL after crosslinking is "like picking a moving target." "You'd have to wait a very long time before you could address the cataract issue, and you wouldn't know the exact degree of BSCVA loss from keratoconus before removing the cataract," he said. Crosslinking is "one more tool to handle our patients with weak continued on page 44