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vision correction, growth strategies 69 Supported by Abbott Medical Optics by Edward Manche, MD The next generation of laser vision correction is now: Highlighting advanced wavefront-guided ablations L aser vision correction (LVC) technology enables sur- geons to deliver excellent visual outcomes, however, laser-induced aberrations may affect visual quality. But with new generation Hartmann-Shack aberrometry, advanced wavefront-guided abla- tion measures data over a 7-mm pupil (vs. 6-mm pupil with previous technology), achieving significantly greater capture. 1–3 Furthermore, it offers approximately five times the resolution of previous technology, increasing accuracy in measuring aberrations over a larger diameter. This technology enables us to image eyes that could not be cap- tured with older technology, such as eyes with keratoconus, previously treated eyes, and eyes with irregular astigmatism. 4 Clinical data In a 2-year multicenter clinical study of 344 eyes, 6 months after advanced wavefront-guided LASIK, 98.2% had uncorrected visual acuity (UCVA) of at least 20/40, 82.6% were at least 20/20, and 61.7% were at least 20/16. 5 The study determined that it was safe and predictable in this time period. We performed wavefront-guid- ed LASIK in 78 eyes of 39 con- secutive patients with advanced wavefront-guided LASIK with a customized nomogram. Four months postoperatively, vision was 20/16 or better in 47%, 20/20 or better in 95.5%, and 20/25 or better in 100% of eyes. When Shaheen et al. treated 20 eyes with highly irregular corneas with advanced wavefront-guided LVC, 10% had uncorrected distance vision of 20/20 or better, 40% 20/25 or better, 90% 20/40 or better, and 100% 20/50 or better. 6 No patients lost vision. Shaheen et al. also reported that corrected and uncorrected distance vision improved significantly after advanced wavefront-guided PRK in patients with keratoconus who had collagen crosslinking at least 1 year previously. 7 Optimizing outcomes I use advanced wavefront-guided ablations for nearly all of my LVC patients with naturally occurring myopia and astigmatism. However, this technology has not been ap- proved in the U.S. for PRK or to treat hyperopia, hyperopic astigmatism, or mixed astigmatism or patients who have had previous refractive surgery. I use wavefront-optimized or topography-guided ablation in cases where I am unable to use advanced wavefront-guided treatments. With any LVC procedure, careful patient selection is critical. We also need to exclude eyes at risk of corneal ectasia by examin- ing corneal topographies carefully. Wavefront-guided ablation removes slightly more tissue than other pro- cedures, so we should be mindful of the posterior stromal limit, leaving 250 µm or more tissue. In addition, we need to ensure scans are high quality. To obtain the most accurate re- sults with this technology, surgeons need to develop their own person- alized nomograms based on their outcomes or eyes may be under- or overcorrected. Conclusion Offering greater resolution and greater dynamic range, advanced wavefront-guided ablation represents a significant step forward in treating naturally occurring refractive error and highly aberrated eyes. Not only does it enable us to achieve high quality results in primary eyes, it is a useful tool to help rehabilitate eyes that have had previous surgery or trauma that we could not treat previously. References 1. Schallhorn SC, et al. Wavefront-guided pho- torefractive keratectomy with the use of a new Hartmann-Shack aberrometer in patients with myopia and compound myopic astigmatism. J Ophthalmol. 2015;2015:514837. 2. Schallhorn S, et al. Early clinical outcomes of wavefront-guided myopic LASIK treatments using a new-generation Hartmann-Shack aberrometer. J Refract Surg. 2014;30:14–21. 3. Prakash G, et al. Femtosecond laser-as- sisted wavefront-guided LASIK using a newer generation aberrometer: 1-year results. J Refract Surg. 2015;31:600–606. 4. Neal DR, et al. Combined wavefront aber- rometer and new advanced corneal topogra- pher. ASCRS 2008; MP392. 5. Summary of safety and effectiveness data (SSED). STAR S4 IR Excimer Laser System and iDesign Advanced WaveScan Studio System. www.accessdata.fda.gov/cdrh_docs/pdf/ P930016S044B.pdf 6. Shaheen MS, et al. Wavefront-guided laser treatment using a high-resolution aberrometer to measure irregular corneas: a pilot study. J Refract Surg. 2015;31:411–418. 7. Shaheen MS. Wave front-guided photore- fractive keratectomy using a high-resolution aberrometer after corneal collagen cross-link- ing in keratoconus. Cornea. 2016;35:946–953. Dr. Manche is professor of ophthal- mology and director of the cornea and refractive surgery division, Byers Eye Institute, Stanford School of Medicine, Stanford, California. He can be contact- ed at email@example.com. Edward Manche, MD later. We provide materials covering these items before surgery. However, it is difficult to get patients to read them, so we created documentation for our chart record, which can come in handy later if a patient challenges the surgeon regarding outcomes. Our messages never include prices, but it is important to adver- tise that we offer financing options and specials to make LVC more affordable. We may target individ- ual groups with our specials, such as teachers in the summer, or we may target broader audiences with a Christmas special. Shaping the message To reach LASIK candidates in a shift- ing environment, market segmen- tation is a useful tool, however, sur- geons need to be sure their messages are focused and consistent. References 1. Q1-2016 Refractive quarterly survey report, Market Scope. 2. Stein JD, et al. Gauging interest of the gen- eral public in laser-assisted in situ keratomil- eusis eye surgery. Cornea. 2013;32:1015– 1018. 3. Millennials Outnumber Baby Boomers and Are Far More Diverse, Census Bureau Reports. United States Census, release number CB15- 113, June 25, 2015. 4. Yesilirmak N, et al. The effect of LASIK on timing of cataract surgery. J Refract Surg. 2016;32:306–310. 5. Stulting RD, et al. Results of topography- guided laser in situ keratomileusis custom ablation treatment with a refractive excimer laser. J Cataract Refract Surg. 2016;42:11–18. 6. Price MO, et al. Three-year longitudinal survey comparing visual satisfaction with LASIK and contact lenses. Ophthalmology. 2016;123:1659–1666. Dr. Stonecipher is clinical associate professor of ophthalmology, University of North Carolina, medical director of TLC Greensboro, and medical director of Physicians Protocol, Greensboro, North Carolina. He can be contacted at StoneNC@aol.com. continued from page 68 Click to read and claim CME credit