1. Myoung Joon Kim, MD / Sara Yoon, MD Tracy Purcell, PhD / David J Schanzlin, MD L aser In Situ Keratomileusis versus Photorefractive Keratectomy for the Treatment of Myopia with CustomVue Platform No author has a financial or proprietary interest in any material or method mentioned.

2.  CustomVue platform provides a wavefront-guided treatment to correct refractive errors. to correct refractive errors.  Literature shows: LASIK Minimal postoperative pain Faster visual recovery Less regression No haze Flap-related complications Interface-related complications Corneal biomechanical instability PRK Safe and effective Postoperative pain Slow visual recovery Corneal haze

3.  Previous studies Few studies have compared LASIK and PRK Few studies have compared LASIK and PRK using CustomVue Platform. § using CustomVue Platform. §PURPOSE  To compare the outcomes of LASIK and PRK in wavefront-guided treatment of low to moderate myopia in wavefront-guided treatment of low to moderate myopia using CustomVue Platfrom using CustomVue Platfrom § Wavefront-guided laser in situ keratomileusis using the WaveScan system for correction of low to moderate myopia with astigmatism: 6-month results in 277 eyes. J Cataract Refract Surg 2005. CustomVue laser in situ keratomileusis for myopia and myopic astigmatism using the Visx S4 excimer laser: Efficacy, predictability, and safety. J Cataract Refract Surg 2006. Wavefront-guided laser in situ keratomileusis in the treatment of high myopia by using the CustomVue wavefront platform. Cornea 2008.

4.  Retrospective control-matched design Duration: Jan. 2006 ~ Dec. 2007 Duration: Jan. 2006 ~ Dec. 2007 Preoperative manifest sphere ≤ -6 D, Cylinder ≤ 2 D Preoperative manifest sphere ≤ -6 D, Cylinder ≤ 2 D Matching criteria: Sphere within ± 1 D, Cylinder within ± 1 D Matching criteria: Sphere within ± 1 D, Cylinder within ± 1 D Age within 10 years Age within 10 years Primary procedure performed in the same year Primary procedure performed in the same year Exclusion criteria: Preoperative BSCVA < 20/25 Exclusion criteria: Preoperative BSCVA < 20/25 Follow-up duration less than 3 months Follow-up duration less than 3 months

5.  Procedure One surgeon (DJS) One surgeon (DJS) LASIK flap creation with IntraLase LASIK flap creation with IntraLase Myopic wavefront-guided treatment targeted at plano Myopic wavefront-guided treatment targeted at plano Mitomycin 0.02% used in PRK Mitomycin 0.02% used in PRK Laser platform: VISX STAR S4 IR (AMO, Santa Ana, CA) Laser platform: VISX STAR S4 IR (AMO, Santa Ana, CA)  Wavefront analysis Between postoperative 1 and 3 months Between postoperative 1 and 3 months WaveScan (AMO, Santa Ana, CA) WaveScan (AMO, Santa Ana, CA) Outcome Analysis Software v4.0 (Outcome Analysis Software, Outcome Analysis Software v4.0 (Outcome Analysis Software, Inc, San Diego, CA) Inc, San Diego, CA)

6. 46 eyes matched (23 eyes per each group) Patients age LASIK group 35.5±9.7 years LASIK group 35.5±9.7 years PRK group 36.2±12.5 years PRK group 36.2±12.5 years P=0.92 P=0.92 Preoperative refractive errors LASIK group SPH -4.10±1.48 D (range -1.75 ~ -6.00) CYL 0.86±0.53 D (range 0 ~ +1.75) PRK group SPH -3.97±1.45 D (range -1.00 ~ -6.00) CYL 0.82±0.51 D (range 0 ~ +1.75) P=0.55 for SPH, 0.77 for CYL

7.  Mean UCVA at 1 month, LogMAR LASIK LASIK 0.03±0.17 0.03±0.17 (LogMAR 0.03 = 20/21.3) (LogMAR 0.03 = 20/21.3)  Mean UCVA at 3 months, LogMAR LASIK LASIK 0.00±0.15 0.00±0.15 (LogMAR 0.00 = 20/20.0) (LogMAR 0.00 = 20/20.0)  Mean UCVA at last follow-up, LogMAR LASIK mean 11.3 months LASIK mean 11.3 months -0.08±0.07 -0.08±0.07 (LogMAR -0.08 = 20/16.7) (LogMAR -0.08 = 20/16.7) PRK0.04±0.08 (LogMAR 0.04 = 20/22.0) P=0.75 PRK0.03±0.15 (LogMAR 0.03 = 20/21.3) P=0.61 PRK mean 11.6 months -0.07±0.10 (LogMAR 0.03 = 20/17.2 ) P=0.57

8.  Cumulative UCVA (Snellen) LASIK PRK % %

9. Among higher-order aberrations, only rms of total higher-order aberration showed statistically significant change (P=0.025). Coma and spherical aberration showed tendency to be increased (P=0.054, 0.055). LASIK

10. PRK Among higher-order aberrations, none of them showed statistically significant change after PRK (P>0.05).

11. Both femtosecond laser LASIK and PRK showed similar good visual outcomes in wavefront-guided treatment of myopia using CustomVue Platform. In LASIK, higher-order aberrations increased significantly postoperatively. Out of components of higher-order aberration, coma and spherical aberration showed tendency to be increased. Radially symmerical component (spherical aberration) may be induced by laser ablation pattern and radially asymmetric component (coma) may be related with flap of LASIK (hinge itself, opaque bubble layer around hinge at the time of flap creation by femtosecond laser).