The Impact of Image Registration for Ablation Orientation on Clinical Outcomes After Wavefront-Optimized Refractive Surgery in Eyes with Myopia and Astigmatism.

Purpose: To compare the clinical outcomes from laser refractive surgery performed with the same laser with and without incorporating iris registration technology to compensate for ocular cyclotorsion.
Design: Single-site, two-arm, retrospective chart review.
Methods: Clinical outcomes at a single site after wavefront-optimized LASIK using the Wavelight excimer laser with and without the Vario imaging system for iris registration (IR) were evaluated. Eligible subjects were those that received on-label wavefront-optimized treatment of myopia with astigmatism >1.5 D. Measures of interest were the amount of residual refractive cylinder after surgery, the refractive error, and the best-corrected (BCVA) and uncorrected (UCVA) visual acuities, with a target follow-up of around 90 days.
Results: A total of 112 eligible eyes that were treated with IR and 126 similar eyes treated without IR (NO IR) were included. The refractive sphere and spherical equivalent refractions were statistically significantly different between groups (p < 0.05), but the mean differences were <0.1 D in both cases. Refractive cylinder averaged around 0.12 D and was not statistically significantly different between groups. The number of eyes with residual cylinder >0.50 D was higher in the NO IR group vs the IR group (6% vs 1%, respectively, p = 0.04). The mean logMAR UCVA and BCVA were statistically significantly better in the IR group, with a difference of 1.5 letters for UCVA and 1.0 letters for BCVA (p < 0.001 for both). Significantly more eyes in the IR group had a UCVA (p = 0.01) and a BCVA of 20/15 or better (p = 0.003). Overall, 96% of eyes in the IR group and 91% of eyes in the NO IR group had uncorrected visual acuity of 20/20 or better.
Conclusion: Iris registration with the VARIO imaging device demonstrably reduced the overall variability in clinical outcomes.
Competing Interests: Dr Phillip B Brunson reports grants from Alcon, during the conduct of the study; a consultant for Novartis Pharmaceuticals, Eyevance Pharmaceuticals, and Allergan Pharmaceuticals, outside the submitted work. Dr Paul Michael Mann and Dr Paul M Mann II report grants from Alcon, during the conduct of the study. Dr Richard Potvin reports personal fees from Alcon and Carl Zeiss Meditec, outside the submitted work. The authors report no other conflicts of interest in this work.
(© 2020 Brunson et al.)