Comparing the two conventional devices of Allegretto EX500 (WaveLight Allegretto Wave Eye-Q Laser; Alcon Laboratories, Inc., Fort Worth, TX) and Technolas Teneo 317 (Bausch & Lomb, Rochester, NY) in terms of maintaining corneal asphericity and high-order aberrations variations under optimized profile in patients with myopic astigmatism.

: Myopic patients (myopia of 1 to 8 diopters and maximum astigmatism of 2.5 diopters) were selected based on the inclusion and exclusion criteria. They were operated randomly by one of the Allegretto EX500 or Technolas teneo 317 devices. Before surgery and six months later complete eye examination and imaging including Orbscan, Zywave, and Topolyzer were performed

Ninety-seven eyes of 49 patients with mean age of 28 ± 5 years were included. Six months after the operation, best corrected visual acuity was similar between the two groups (P = 0.152). The spherical equivalent was -3.43 ± 1.29 and -2.91 ± 1.29 (P = 0.047) before the operation and -0.14 ± 0.19 and 0.08 ± 0.23 (P = 0.173) six months after the operation in the Allegretto and Teneo groups, respectively. There was no significant difference between the third-order and fourth-order corneal aberrations of two devices before and after the operation (P> 0.05). The ocular high-order aberrations increased from 0.3 ± 0.1 and 0.31 ± 0.12 (P=0.639) to 0.43 ± 0.2 and 0.42 ± 0.18 (P = 0.828), respectively, in the Allegretto and Teneo devices. Corneal asphericity at central 30 ° was -0.3 ± 0.12 and -0.38 ± 0.51 (P = 0.25) before the operation and 0.28 ± 0.26 and 0.28 ± 0.25 (P = 0.858) after the operation in the Allegretto and Teneo groups. This increase was more as much as one spherical equivalent diopter in the Teneo group (P = 0.628).

Under the optimized profile, the results of the treatment of myopic astigmatism patients were similar between the Allegretto and Teneo devices. However, the asphericity variations are less in Allegretto device and Teneo device induces lower high-order aberrations.