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EW NEWS & OPINION 20 eyes (20.5%)," Dr. Guell reported. "The ICRS was 250 mm thick in 1 eye, 300 mm thick in 7 eyes, 350 mm thick in 4 eyes, 400 mm thick in 15 eyes, and 450 mm thick in 12 eyes." Mean spherical equivalent was –2.89 D +/–0.99 D pre-op, improving to –0.56 +/–0.24 D 4 years post-op. Mean cylinder was reduced from –1.26 +/–1.21 D pre-op to –1.06 +/–0.55 D post-op. There were no significant changes in spherical equivalent or cylinder between 3 months post-op and 4 years post-op, "showing the stability of the refractive correction," Dr. Guell reported. "In terms of refractive pre- dictability, 32 eyes (82.05%) were within +/–1.00 D of emmetropia and 18 eyes (46.15%) were within +/– 0.50 D," Dr. Guell reported. "The ICRS were exchanged for thicker seg- ments in 7 eyes (17.9%) within 1 month after primary surgery because of undercorrection. Four years after exchange surgery, all eyes were within +/–1.00 D of emmetropia and 25 eyes (63.6%) were within +/– 0.50 D of emmetropia." Still, one patient did ask for In- tacs explantation and subsequently received LASIK. "The patient was a professional golfer who sought ex- cellent UDVA [uncorrected distance visual acuity]," Dr. Guell reported. "After ICRS extraction, LASIK was performed successfully in this pa- tient, whose only contraindication to excimer laser surgery was an ab- normal posterior elevation map. Seven years after LASIK, the UDVA was 20/15 in both eyes." Nonetheless, Dr. Guell reported that UDVA improved during the fol- low-up period for patients. "Four years postoperatively, all the eyes had a UDVA of 20/40 or better and 4 eyes, of 20/20 or better," Dr. Guell noted. "In our study of myopic pa- tients with abnormal topography, the UDVA continued to improve up to 6 months even though the refrac- tion was stable from 3 months for- ward. The effect of ICRS implantation on refraction and vi- sual acuity is not completely under- stood. Corneal characteristics, such as central and peripheral pachyme- try, corneal irregularity, or hysteresis, as well as unknown factors may in- fluence the effects of ICRS implanta- tion, especially in eyes with an abnormal cornea." Meanwhile, Audrey R. Talley- Rostov, M.D., Seattle, who uses In- tacs to treat keratoconus patients, said she would not describe Intacs as a myopia-correcting device. "I use Intacs for keratoconus and not low myopia," Dr. Talley-Ros- tov said. "If you're treating someone who is not a good laser vision candi- date with Intacs, what you're doing with the intrastromal corneal ring segment is normalizing the cornea and changing the biomechanical ef- fect." She suggested that myopia cor- rection in such instances is more likely a desirable side effect. "If a pa- tient has abnormal topography, such as forme fruste keratoconus, you're not really treating myopia per se," Dr. Talley-Rostov said. "If someone is a –2 or –3 D myope and has a healthy cornea, then assuming all other things being equal and if he or she is a good candidate for laser vi- sion correction, I would not offer In- tacs." EW Editors' note: Dr. Guell reported no fi- nancial interests related to this study. Dr. Talley-Rostov has financial interests with Addition Technology (Des Plaines, Ill.). Contact information Guell: guell@imo.es Talley-Rostov: ATalleyRostov@nweyes.com February 2011 Using continued from P. 19

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