Eyeworld

EW MEETING REPORTER November 2011 57 Monday, September 19 Careful measurements and marking of the axis pre-op to prevent IOL ro- tation is important, especially since mean deviation on patients varies widely, with 4 degrees being the av- erage and 15 degrees on the high end, Roger Steinert, M.D., Irvine, Calif., said during the Combined Symposium of Cataract and Refrac- tive Societies. Therefore, axis orien- tation must be performed with the patient in an upright, not supine, position, he said. "Once a patient is draped, it is very hard to figure out where the corneal plane is. You lose all your landmarks," Dr. Steinert said. "You can be off from not seeing the patient's skull clearly. Cyclotor- sion is the rule, not the exception, in the supine patient." Dr. Steinert listed some new technologies that are making it easier for surgeons to accurately orient lenses, including TrueVision's intelligent 3D visualiza- tion system (TrueVision Systems, Santa Barbara, Calif.), SMI's SG5000 Surgery Guidance (SMI, Teltow, Ger- many), and Zeiss's Callisto, the just- announced modular platform of Callisto Eye, which now integrates its camera system with a pre-op measurement from the IOLMaster (Carl Zeiss Meditec, Dublin, Calif.). Technology for true intraop- erative verification, such as the ORange aberrometer (WaveTec Vision, Aliso Viejo, Calif.), is also available, but more development needs to take place, with considera- tion paid to the overall value of the systems, Dr. Steinert said. Corneal surgical techniques: Treating keratoconus with intracorneal implants Addition Technology's Intacs (Des Plaines, Ill.) and ring segments such as the Ferrara Ring (Ferrara Oph- thalmics, Spain), which is currently not approved for use in the U.S., can be used to stabilize keratoconus and prevent its progression, especially since the addition of femtosecond laser technology can produce the channels very quickly in about 12 to 15 seconds, according to Dr. Colin. Adding crosslinking to the procedure is also helpful, he said. "The synergistic linking of these two technologies is very use- ful; however, remember that crosslinking is not a refractive treat- ment, and patients may be disap- pointed because they lose vision over a few weeks, and after a few weeks they do not gain vision," he said. Several studies reportedly have demonstrated that rings are able to improve the shape and visual acuity of patients with keratoconus and de- crease higher order aberrations. "When we look at the literature, there are at least 150 papers on re- sults of rings for keratoconus, and all the papers report that 70-80% of eyes gain lines," Dr. Colin said. Nomograms for the procedure will guide the surgeon to adjust the depth, width, and location of the implants into the corneal stroma. Combining crosslinking with rings depends on the type of keratoconus, Dr. Colin said. A patient with pro- gressive keratoconus who is contact lens tolerant will require immediate crosslinking, while a progressive pa- tient who is contact lens intolerant will require both implantation and crosslinking at the same time. If the disease is non-progressive and the patient is able to tolerate contact lenses, no procedure is performed, but if the patient can't tolerate con- tact lenses, Dr. Colin said, "no crosslinking, please." "Intacs and topoguided PRK or toric IOLs may help this patient," he said. Your ASCRS membership now lets you take the ASCRS Symposium home. With the new ASCRS MediaCenter all the highlights of ASCRS 2011 are now right on your computer. Films, papers and posters exactly as they were presented in an easy-to-use and fully-searchable format. See what you missed or re-visit what you liked most. Search by topic, presenter or key-word. It's the best of ASCRS without leaving home. Log in at www.ascrs.org and click on ASCRS MediaCenter in the left-hand column for complete access. Make your ASCRS membership work harder! Begin learning today! continued on page 59

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