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Majid Moshirfar,1,2 Tirth J Shah,3 David Franklin Skanchy,4 Steven H Linn,1 Paul Kang,3 Daniel S Durrie5 1HDR Research Center, Hoopes Vision, Salt Lake City, UT, 2Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT, 3University of Arizona College of Medicine – Phoenix, Phoenix, AZ, 4McGovern Medical School, The University of Texas Health Science Center at Houston, TX, 5Durrie Vision, Kansas City, KS, USA Purpose: To compare and analyze the differences in visual outcomes between Visx iDesign Advanced WaveScan Studio™ System, Alcon Wavelight Allegro Topolyzer and Nidek EC-5000 using Final Fit™ Custom Ablation Treatment Software from the submitted summary of safety and effectiveness of the US Food and Drug Administration (FDA) data.Methods: In this retrospective comparative study, 334 eyes from Visx iDesign, 212 eyes from Alcon Contour, and 135 eyes from Nidek CATz platforms were analyzed for primary and secondary visual outcomes. These outcomes were compared via side-by-side graphical and tabular representation of the FDA data. Statistical significance was calculated when appropriate to assess differences. A P-value

Aim The aim of the present study was to compare the differences in visual outcomes, higher-order aberrations and corneal asphericity, as measured by Q values, in patients undergoing laser in-situ keratomileusis using wavefront-guided variable-spot size VISX CustomVue and wavefront-optimized small-spot size WaveLight Allegretto platforms. Type of study This study was designed as a randomized, prospective, single-blinded, double-armed, fellow-eye comparative study. Patients and methods A total of 100 eyes of 50 patients undergoing customized laser in-situ keratomileusis for compound myopic astigmatism were enrolled and randomly divided into two groups. Each patient underwent full ophthalmological examination; aberrometry was performed on either eye by using VISX CustomVue aberrometer and Allegretto WaveLight aberrometer. Each patient had one eye examined using the Allegretto Wave eye Q system (small-spot scanning), and the fellow eye by using VISX Star CustomVue S4 system (variable-spot scanning). All patients were given postoperative steroids, antibiotic drops and artificial tears. First day postoperative visit was scheduled to check for flap stability, and to exclude complications. Clinical examination and best corrected visual acuity, corneal imaging and aberrometry were scheduled at 1 month and 1 year later. Results Final best corrected visual acuity showed insignificant difference between the two groups (P = 0.712). The final differences between the groups were insignificant in all other parameters. Conclusion The two ablation profiles are highly comparable in treating compound myopic astigmatism.

Purpose: The aim of the study was to determine and compare the relationship between change in simulated keratometry (K) and degree of refractive correction in wavefront-guided (WFG) and wavefront-optimized (WFO) myopic laser-assisted in situ keratomileusis (LASIK). Methods: A total of 51 patients were prospectively randomized to WFG LASIK in one eye and WFO LASIK in the contralateral eye at the Byers Eye Institute, Stanford University. Changes in simulated K and refractive error were determined at 1 year post-operatively. Linear regression was employed to calculate the slope of change in simulated K (ΔK) for change in refractive error (ΔSE). The mean ratio (ΔK/ΔSE) was also calculated. Results: The ratio of ΔK to ΔSE was larger for WFG LASIK compared to WFO LASIK when comparing the slope (ΔK/ΔSE) as determined by linear regression (0.85 vs 0.83, p = 0.04). Upon comparing the mean ratio (ΔK/ΔSE), subgroup analysis revealed that ΔK/ΔSE was larger for WFG LASIK for refractive corrections of >3.00 D and >4.00 D (0.89 vs 0.83; p = 0.0323 and 0.88 vs 0.83; p = 0.0466, respectively). Both linear regression and direct comparison of the mean ratio (ΔK/ΔSE) for refractive corrections <4.00 D and >4.00 D revealed no difference in ΔK/ΔSE between smaller and larger refractive corrections. Conclusion: WFO LASIK requires a smaller amount of corneal flattening compared to WFG LASIK for a given degree of refractive correction. For both, there was no significant difference in change in corneal curvature for a given degree of refractive error between smaller and larger corrections. [ABSTRACT FROM AUTHOR]

Aim: The aim of the present study was to compare the differences in visual outcomes, higherorder aberrations and corneal asphericity, as measured by Q values, in patients undergoing laser in-situ keratomileusis using wavefront-guided variable-spot size VISX CustomVue and wavefront-optimized small-spot size WaveLight Allegretto platforms. Type of study: This study was designed as a randomized, prospective, single-blinded, double-armed, felloweye comparative study. Patients and methods: A total of 100 eyes of 50 patients undergoing customized laser in-situ keratomileusis for compound myopic astigmatism were enrolled and randomly divided into two groups. Each patient underwent full ophthalmological examination; aberrometry was performed on either eye by using VISX CustomVue aberrometer and Allegretto WaveLight aberrometer. Each patient had one eye examined using the Allegretto Wave eye Q system (small-spot scanning), and the fellow eye by using VISX Star CustomVue S4 system (variable-spot scanning). All patients were given postoperative steroids, antibiotic drops and artificial tears. First day postoperative visit was scheduled to check for fl ap stability, and to exclude complications. Clinical examination and best corrected visual acuity, corneal imaging and aberrometry were scheduled at 1 month and 1 year later. Results: Final best corrected visual acuity showed insignificant difference between the two groups (P = 0.712). The fi nal differences between the groups were insignificant in all other parameters. Conclusion: The two ablation profiles are highly comparable in treating compound myopic astigmatism. [ABSTRACT FROM AUTHOR]

The pace of advancement in refractive surgical techniques and evolution of technology in recent years has been remarkably brisk. The increase in technologies and treatment options, however, has left many ophthalmologists uncertain as to which are the optimal choices for their patients and practices. Some of this dilemma undoubtedly arises from the expanding ‘alphabet soup’ of refractive technical terms: radial keratotomy (RK), astigmatic keratotomy (AK), limbal-relaxing incisions (LRI), photorefractive and astigmatic keratectomy (PRK) and (PARK), laser in situ keratomileusis (LASIK), laser subepithelial keratomileusis (LASEK), epithelial laser in situ keratomileusis (Epi-LASIK), IntraLase LASIK (Intra-LASIK), intracorneal ring segments (ICRS), laser thermokeratoplasty (LTK), conductive keratoplasty (CK), phakic intraocular lenses (PIOL), clear lens extractions (CLE), refractive lens exchange (RLE) and scleral expansion (SE), to name just a few. Within the parameters of a single technology, such as laser vision correction (LVC), there are numerous approaches to optimizing visual outcomes. For example, in the last 5 years, the development of wavefront technology has revolutionized the way refractive surgeons view and treat refractive error. The discussion continues, however, as to when or how to best use this technology. To date, there are two wavefront-based approaches to LVC: wavefront guided and wavefront optimized. The purpose of this article is to discuss the use of wavefront analysis and to explore wavefront-guided and wavefront-optimized approaches in LVC. [ABSTRACT FROM AUTHOR]

Purpose: To compare outcomes in visual acuity, refractive error, higher-order aberrations (HOAs), contrast sensitivity, and dry eye in patients undergoing laser in situ keratomileusis (LASIK) using wavefront (WF) guided VISX CustomVue and WF optimized WaveLight Allegretto platforms., Methods: In this randomized, prospective, single-masked, fellow eye study, LASIK was performed on 44 eyes (22 patients), with one eye randomized to WaveLight Allegretto, and the fellow eye receiving VISX CustomVue. Postoperative outcome measures at 3 months included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, root-mean-square (RMS) value of total and grouped HOAs, contrast sensitivity, and Schirmers testing., Results: Mean values for UDVA (logMAR) were -0.067 ± 0.087 and -0.073 ± 0.092 in the WF optimized and WF guided groups, respectively (P = 0.909). UDVA of 20/20 or better was achieved in 91% of eyes undergoing LASIK with both lasers while UDVA of 20/15 or better was achieved in 64% of eyes using the Allegretto platform, and 59% of eyes using VISX CustomVue (P = 1.000). In the WF optimized group, total HOA increased 4% (P = 0.012), coma increased 11% (P = 0.065), and spherical aberration increased 19% (P = 0.214), while trefoil decreased 5% (P = 0.490). In the WF guided group, total HOA RMS decreased 9% (P = 0.126), coma decreased 18% (P = 0.144), spherical aberration decreased 27% (P = 0.713) and trefoil decreased 19% (P = 0.660). One patient lost one line of CDVA secondary to residual irregular astigmatism., Conclusion: Both the WaveLight Allegretto and the VISX CustomVue platforms had equal visual and safety outcomes. Most wavefront optimized HOA values trended upward, with a statistically significant increase in total HOA RMS. Eyes treated with the WF guided platform showed a decreasing trend in HOA values.