Eyeworld

EW CATARACT June 2011 29 Limbal relaxing incisions are contraindicated in patients with ker- atoconus, making toric lenses a "rea- sonable alternative," Dr. Donnenfeld said. "Under no circumstances would I implant a multifocal lens in these patients," Dr. Lane said. Also, patients with keratoconus may end up developing cataracts earlier than normal, Dr. Devgan said. "PSC [posterior subcapsular cataracts] can go from nothing to terrible in the course of a month. In the example Dr. Jaffee presented, I'd aim for plano to –1 D as a good tar- get for the right eye and perhaps use a toric IOL depending on topogra- phy." Toric IOLS are only available at this time to correct about 2 D of regular astigmatism, though. "If someone has astigmatism larger than that, you may not be doing him any favors by implanting a toric lens," Dr. Devgan said. Dr. Donnenfeld supports per- forming manual keratotomy in these eyes, but Dr. Devgan advised using whichever software program is pre- ferred. The downside to using any of the typical IOL calculation formulas is that they make an assumption where in the eye the IOL will sit based on the Ks and axial length, so the formulas will assume that be- cause the K values are extreme, the lengths will also be extreme, Dr. Devgan said. Dr. Donnenfeld, while a con- firmed advocate of toric lenses in keratoconus, "would never place one if the patient is comfortable with gas permeable contact lenses because they presume a lenticular cylinder of zero. As soon as you place cylinder into the eye, the patient will end up with residual cylinder that will not be correctable with a gas permeable lens," he said. By using a toric lens in Dr. Jaffee's example, reducing the cylin- der to under 4 D "will make the pa- tient much more spectacle correctable, assuming the patient doesn't wear gas permeable lenses." Bottom line? "Choose an IOL that will err on the side of leaving the patient myopic," Dr. Lane said. "I'd rather have a patient end up –1.00 D or –1.50 D than +1.00 D or +1.50 D." Dr. Jaffee has not yet operated on the patient, but plans on im- planting an SN20WF lens (Alcon, Fort Worth, Texas) and leaving the patient about –3.00 D, he said. EW Editors' note: Dr. Devgan has financial interests with Abbott Medical Optics (AMO, Santa Ana, Calif.), Alcon, Bausch & Lomb (Rochester, N.Y.), Haag-Streit (Mason, Ohio), and Hoya (Santa Clara, Calif.). Dr. Donnenfeld has financial interests with AMO, Alcon, Bausch & Lomb, and WaveTec. Dr. Lane has financial interests with AMO, Alcon, Bausch & Lomb, and WaveTec. Contact information Devgan: 800-337-1969, devgan@gmail.com Donnenfeld: 516-766-2519, eddoph@aol.com Lane: 651-275-3000, sslane@ associatedeyecare.com Now available eyeworld.org/blevent2011 Crystalens Breakfast Symposium from the 2011 ASCRS•ASOA Symposium and Congress Moderator: John A. Hovanesian, MD Faculty: Harvey Carter, MD Y. Ralph Chu, MD Steven J. Dell, MD Guy M. Kezirian, MD Jay S. Pepose, MD, PhD Robert J. Weinstock, MD

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