EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/76185
July 2012 EW NEWS & OPINION 19 gery alters the corneal asphericity, thereby changing corneal aberra- tions. Aspheric IOLs assume that the cornea has positive sphericity; how- ever, prior hyperopic LASIK may induce corneal negative asphericity, while myopic LASIK causes a shift toward more positive asphericity. Without taking this into considera- tion, and without employing the correct IOL power calculation for- mula, it is easy to select a less than optimal lens design for this patient population. The best IOL choice, then, is one that neutralizes the cornea's spherical aberration or at least does not add additional aberra- tion. Final considerations 1. In the setting of a post-refractive patient undergoing cataract surgery, it may be useful to use topical anes- thesia in surgery in order to keep pa- tients in the post-op recovery room and check for residual refractive error. If the power is obviously incorrect immediately post-op, returning to the operating room and performing an IOL exchange is an option. 2. Patient education and in- formed consent are of the utmost importance in performing cataract surgery on the post-refractive pa- tient. Expectations regarding post-op accuracy should be outlined and managed pre-op. Patients must un- derstand that spectacle independ- ence after cataract surgery, especially in the setting of previous corneal refractive surgery, cannot be guaranteed. 3. The use of premium IOLs, in- cluding accommodating, multifocal, and astigmatic-correcting lenses, in the post-refractive patient popula- tion can be challenging, as their outcomes are more unpredictable. 4. The utilization of intraopera- tive aberrometry is the ideal scenario; however, it is not readily accessible for most surgeons. 5. If there is a surprise refractive error, IOL exchange, additional corneal refractive surgery, or piggy- backing a sulcus IOL are options. EW References Chang DF. Mastering refractive IOLs: the art and science. Thorofare: SLACK Incorporated, 2008. Print. 1. DuoVisc® OVD Product Insert. © 2011 Novartis 11/11 VIS11628JAD One System. No Compromises. Hill WE, Wang L, Koch DD. American Society of Cataract & Refractive Surgery Post-Keratore- fractive Intraocular Lens Power Calculator. iol.ascrs.org. Accessed: May 2012. Kugler LJ, Wang MW. Lasers in refractive surgery: history, present, and future. Appl Opt. 2010;49(25):F1-9. Krueger RR, Rabinowitz YS, Binder PS. The 25th anniversary of excimer lasers in refractive surgery: historical review. J Refract Surg. 2010;26(10):749-60. continued on page 20 Only One System Delivers the Shield of PROTECTION. DuoVisc® VISCOAT® Viscoelastic System offers both the endothelial protection of chondroitin sulfate in OVD with the proven mechanical protection and space maintenance found in PROVISC® OVD.1