Comparative analysis of outcomes following topography-guided laser in situ keratomileusis using manifest refraction versus a new topographic analysis algorithm

PURPOSE: To compare the visual outcomes following topography-guided laser in situ keratomileusis (LASIK) treatment using manifest refraction versus a new topography analysis software. METHODS: A prospective, randomized, observer-masked contralateral study was conducted in the refractive services of a tertiary eye care hospital in South India. Analysis of visual outcomes, corneal higher-order aberrations, and contrast sensitivity were performed at 3 months postoperative visit following uneventful topography-guided LASIK using the Wavelight EX500. One eye was treated with the Contoura platform using manifest refraction (Contoura), while the contralateral eye was treated using an ablation profile planned by the Phorcides Analytic Engine (Phorcides). RESULTS: Sixty eyes of 30 patients were included in the study. At 3 months postoperative visit, the uncorrected distance visual acuity (UDVA) in the Contoura and Phorcides groups was logarithm of the minimal angle of resolution (logMAR) 0.04 ± 0.07 and logMAR 0.06 ± 0.1, respectively (P = 0.483). Postoperative manifest refractive spherical error (MRSE) was 0.12 ± 0.22 and − 0.06 ± 0.20 D in the Contoura and Phorcides groups, respectively (P = 0.338). Although higher number of eyes demonstrated a gain in one or more lines of corrected distance visual acuity (CDVA) in the Contoura group (16.6% vs. 6.6%), the difference was not statistically significant (P = 0.361). Vector analysis (Alpins criteria) for postoperative cylinder, contrast sensitivity measurement, and corneal higher-order aberration profile showed no significant difference between the two groups at 3 months postoperative visit (P = 0.213, 0.514, and 0.332, respectively). CONCLUSION: Quantitative and qualitative visual outcomes with the Phorcides Analytic Software were similar to the Contoura treatment using manifest refraction.