To compare long-term results of femto-LASIK and photorefractive keratectomy (PRK) as a factor of baseline astigmatism in patients with less than 2.0 diopters (D) of spherical error and more than 2.0D of cylinder error.

In this retrospective study, data was extracted from 100 patient charts. The two study groups were matched by age, gender, and baseline uncorrected distance visual acuity (UDVA) and refractive astigmatism (RA) (all P>0.05). Preoperative astigmatism was categorized as mild: 2.00 to <3.00D, moderate: 3.00 to <4.00D, and severe: ≥4.00D. Results were compared at 1 and 2 years using independent sample t-tests.

Mean RA in the femto-LASIK and PRK groups were respectively -3.15±0.94D (-7.00 to -2.00D) and -3.29±0.95D (-6.25 to -2.00D) at baseline (P=0.284), and -0.61±0.40D and -0.62 ±0.60D at one year after surgery (P=0.674), but significantly lower in the femto-LASIK group (-0.61±0.39 vs. -0.83±0.56D, P=0.021) at 2 years when the rate of residual astigmatism more than 1D was 6.3% in the femtoLASIK and 19.6% in the PRK group (P=0.046). Mean UDVA in the femto-LASIK group (0.02 ±0.05LogMAR) was better than the PRK group (0.06±0.10LogMAR) (P=0.025). The inter-group difference in mean corrected distance visual acuity (CDVA) was not significant (0.01±0.03 vs. 0.01±0.04LogMAR, P=0.714). The three subgroups did not differ significantly in terms of residual astigmatism (all P>0.05).

Our results pointed to better long-term results with femto-LASIK in the treatment of different severity of astigmatism. UDVA improvement was superior with femto-LASIK, but the two methods did not differ in terms of CDVA improvement.