Toric laser in situ keratomileusis for myopic astigmatism using an ablatable mask

BACKGROUND: To assess the results of toric laser in situ keratomileusis (LA SIK) correction of myopic astigmatism. METHODS: A prospective study was performed over a 20 week period for consec utive patients treated for myopic astigmatism. Spectacle-corrected visual a cuity, uncorrected visual acuity, spectacle refraction, videokeratography, and complications were recorded. Vector analysis was performed by the ASSOR T program. RESULTS: Sixty-five eyes of 42 patients underwent toric LASIK with a Summit Technologies Apex Plus excimer laser. Mean preoperative spherical equivale nt refraction at the spectacle plane was -6.24 +/- 2.42 D (range, -1.63 to -14.63 D) and mean preoperative refractive cylinder magnitude was 1.99 +/- 1.35 D (range, 0.75 to 7.00 D); mean attempted refractive cylinder correcti on was 1.90 +/- 1.00 D. Six months after LASIK (43 eyes followed), mean sph erical equivalent refraction at the spectacle plane was -0.40 +/- 0.55 D an d 31 eyes (72.1%) were within +/-0.50 D of emmetropia. At 6 months, mean re fractive cylinder magnitude was 0.74 +/- 0.70 D, mean surgically induced as tigmatism was 1.46 +/- 0.86 D, mean absolute angle of error was 10.33 degre es, mean astigmatic correction index was 0.93 +/-: 0.36 D, and mean index o f success was 0.46 +/- 0.39. Uncorrected visual acuity was 6/12 or better i n 34 eyes (79.1%) and 6/6 in 15 eyes (35%); spectacle- corrected visual acu ity was 6/9 or better in 41 eyes (95.35%). Six eyes (14.0%) lost 1 line of spectacle-corrected visual acuity at 6 months and one eye (2.3%) lost 2 lin es. Ten eyes (23.3%) gained 1 line at 6 months. CONCLUSION: Toric LASIK with an ablatable mask using the Summit Apex Plus e xcimer laser is a safe and relatively accurate procedure for the correction of myopic astigmatism.