Prospective, randomized, fellow eye comparison of WaveLight® Allegretto Wave® Eye-Q versus VISX CustomVueTM STAR S4 IRTM in photorefractive keratectomy: analysis of visual outcomes and higher-order aberrations

Abstract

BackgroundThe purpose of this study was to compare differences in visual outcomes, higher-order aberrations, contrast sensitivity, and dry eye in patients undergoing photorefractive keratectomy using wavefront-guided VISX CustomVue™ and wavefront-optimized WaveLight® Allegretto platforms.MethodsIn this randomized, prospective, single-masked, fellow-eye study, photorefractive keratectomy was performed on 46 eyes from 23 patients, with one eye randomized to WaveLight Allegretto, and the fellow eye receiving VISX CustomVue. Three-month postoperative outcome measures included uncorrected distance visual acuity, corrected distance visual acuity, refractive error, root mean square of total and grouped higher-order aberrations, contrast sensitivity, and Schirmer’s testing.ResultsMean values for uncorrected distance visual acuity (logMAR) were −0.03 ± 0.07 and −0.06 ± 0.09 in the wavefront-optimized and wavefront-guided groups, respectively (P = 0.121). Uncorrected distance visual acuity of 20/20 or better was achieved in 91% of eyes receiving wavefront-guided photorefractive keratectomy, and 87% of eyes receiving wavefront-optimized photorefractive keratectomy, whereas uncorrected distance visual acuity of 20/15 was achieved in 35% of the wavefront-optimized group and 64% of the wavefront-guided group (P ≥ 0.296). While root mean square of total higher-order aberration, coma, and trefoil tended to increase in the wavefront-optimized group (P = 0.091, P = 0.115, P = 0.459, respectively), only spherical aberration increased significantly (P = 0.014). Similar increases were found in wavefront- guided root mean square of total higher-order aberration (P = 0.113), coma (P = 0.403), trefoil (P = 0.603), and spherical aberration (P = 0.014). There was no significant difference in spherical aberration change when comparing the two platforms. The wavefront-guided group showed an increase in contrast sensitivity at 12 cycles per degree (P = 0.013).ConclusionBoth VISX CustomVue and WaveLight Allegretto platforms performed equally in terms of visual acuity, safety, and predictability in photorefractive keratectomy. The wavefront-guided group showed slightly improved contrast sensitivity. Both lasers induced a comparable degree of statistically significant spherical aberration, and tended to increase other higher-order aberration measures as well.

Retrospective Analysis Comparing the Preoperative and Postoperative “Q” Values for 2 Different Lasers in Refractive Surgery

“…Similarly, in some retrospective studies comparing VISX CustomVue with WaveLight Allegretto platforms in laser in situ keratomileusis 17 and PRK, 16,18 there was no significant difference in visual outcomes or induced HOAs. Although we did not include HOA RMS analysis in this study, our results closely match with other published results obtained by comparing both lasers.…”

“…[13][14][15] It has been suggested that both lasers have a similar effect on the final HOA. 11,16,17 However, on review of the literature, no studies examining the effect of lasers on the Q value for PRK were found.…”

Retrospective Analysis of the Post-Operative Changes in Higher-Order Aberrations: A Comparison of the WaveLight EX500 to the VISX S4 Laser in Refractive Surgery

“…Yet, subjects treated with the VISX CustomVue showed significantly improved contrast sensitivity. 6 Furthermore, the platforms had equal visual acuity outcomes when used for LASIK even though a statistically significant increase in total higher-order aberrations was noted with the WaveLight Allegretto and eyes treated with the VISX CustomVue showed a decreasing trend in higher-order aberrations. 7 Some have argued that the change in higher-order aberrations may be more clinically noted than the absolute change.…”

“…5 Moshirfar et al demonstrated both the VISX CustomVue and WaveLight Allegretto systems perform equally in terms of visual acuity, safety, and predictability in both PRK and LASIK refractive surgery procedures. 6,7 Both platforms induced a comparable degree of higher-order and spherical aberrations during PRK, though no statistically significant difference in terms of the RMS of higher-order optical aberrations was demonstrated. 6 Interestingly, eyes treated with the wavefront-guided VISX CustomVue were shown to have decreased higher-order aberrations following LASIK, whereas eyes treated with the wavefront-optimized Allegretto had an upward trend in higher-order aberration values.…”

“…6,7 Both platforms induced a comparable degree of higher-order and spherical aberrations during PRK, though no statistically significant difference in terms of the RMS of higher-order optical aberrations was demonstrated. 6 Interestingly, eyes treated with the wavefront-guided VISX CustomVue were shown to have decreased higher-order aberrations following LASIK, whereas eyes treated with the wavefront-optimized Allegretto had an upward trend in higher-order aberration values. 7 Molchan et al demonstrated a smaller change in corneal asphericity per diopter of treatment with myopic correction using the Allegretto wavefront-optimized laser when compared to the VISX wavefront-guided laser for refractive surgery.…”