EyeWorld India December 2014 Issue

65 EWAP NEWS & OPINION December 2014 selection based on their own personal experience. The aim of the session was to have the chairs, panelists, and attendees all learn together through the discussion, Dr. Barrett said, to distill the best pearls for calculating IOL power. “There’s no more important topic than what we’re going to talk about, which is how to get better outcomes for your patient,” Dr. Barrett said. “All this technology in the world is of no use to you unless you get a perfect outcome.” Drs. Barrett and Hill presented several clinical scenarios of patients with unusual eyes and showed how various power calculation formulas performed in each situation. Drs. Barrett and Hill demonstrated that in a high axial myope, standard formulas yield hyperopic errors. In these cases, when using the SRK/T, Holladay I, HQ or Haigis formulas, be sure to include the axial length adjustment that will reduce the error and make it slightly myopic. Drs. Barrett and Hill and the panelists agreed that the best formula for myopic eyes— eyes longer than 25 mm—is the Barrett II universal. In post-LASIK patients, the biggest take home message is that the history method is not the gold standard, Dr. Barrett said. If you have pre-op k readings, ignore them, he said, but do include the pre-op refraction if it is available. Drs. Barrett and Hill agreed that surgeons should use the modified Masket, mean ASCRS, or Barrett true K formulas in these situations, and if you’re using a standard formula, don’t include the axial length adjustment. Calculating IOL power for toric lenses can be especially challenging. Many formulas end up leaving the patient with against- the-rule astigmatism, Dr. Barrett said, because they don’t factor in the posterior cornea. The best thing to do for toric IOL calculations, Drs. Barrett and Hill said, is to make sure you include the posterior corneal astigmatism. Drs. Barrett and Hill agreed that axial hyperopes, with short axial lengths, flat corneas, and large white-to-white measurements are their worst nightmares when it comes to IOL power prediction. Once you get a white-to-white greater than 13 mm, Dr. Hill said, the formulas begin to breakdown. “If the assumptions of the formulas do not match the anatomy of the eye, you’re guaranteed a refractive surprise,” he said. Drs. Barrett and Hill recommended using advanced formulas rather than standard formulas in these cases. “When you have unusual eyes, be careful with standard formulas,” Dr. Barrett said. “This is a time when advanced formulas can be helpful.” 2014 Cornea Highlights The Asia Cornea Society provided a concise cornea and ocular suface disease update for anterior segment surgeons in a symposium Saturday afternoon. The symposium comprised all the “Cornea Highlights of 2014” relevant to both cataract and refractive surgeons. Chul Young Choi, MD , Seoul, South Korea, discussed new indications for high-frequency radiowave-electrosurgery (HRES). “There’s a new field of conjunctival surgeries,” Dr. Choi said. He said that HRES has long been common in mucosal or dermal surgery, particularly rejuvenation cosmetic surgeries. The use of high-frequency radiowaves in electrosurgery delivered through a needle electrode, he said, has the advantage of minimizing heat dispersion to adjacent tissues, and so increases safety by avoiding colateral damage. While HRES has already been used in the treatment of trichiasis and dry eye, new ophthalmic indications include conjunctivochalasis, lymphangiectasis, superior limbic keratitis, and chronic chemosis. While most studies suggest that deep anterior lamellar keratoplasty (DALK) and endothelial keratoplasty (EK) have major advantages over penetrating keratoplasty (PK), The Australian Cornea Graft Registry recently released data showing that lamellar surgery is not as effective as PK. The Australian data distinguished between efficacy— results of studies conducted under ideal conditions—and effectiveness—results under so- called real world conditions—with the Registry touting that its data reflected the latter. Arundhati Anshu, MD , Singapore, presenting a talk for Dr. Donald Tan, Singapore, offered a rejoinder based on data from their own Singapore Corneal Transplant Study (SCTS). The study has tracked over 3,000 cases since 2000. Dr. Anshu traced the evolution of keratoplasty—and attendant survival rates, in their experience— from the days of open sky PK through the various techniques for Descemet’s-stripping automated endothelial keratoplasty (DSAEK). Over the years they’ve performed DSAEK using the taco-fold technique, using a Sheets glide, and finally using Dr. Tan’s Tan EndoGlide. Each iteration has progressively improved on the postop endothelial cell loss: PK had a 40% loss, DSAEK with the taco 61.4%, DSAEK Sheets glide 29.5%, and DSAEK EndoGlide 14.9%. “DSAEK with the EndoGlide is exceptionally good,” said Dr. Anshu. “Our results with DSAEK using the EndoGlide confirms that DSAEK provided for better visual outcomes and fewer complications.” Five-year results, she added, show continued superiority of DSAEK over PK. continued on page 65