Outcomes of spherocylinder treatments in the comprehensive refractive surgery LASIK study

The CRS LASIK Study is a surgeon-sponsored collaborative project to evaluate LASIK outcomes with the Summit and VISX lasers. The current report includes 3-month outcomes in the first group of patients who underwent spherocylindrical corrections of 1 to 10 diopters of myopia and 1 to 4 diopters of astigmatism with the Summit Apex Plus and VISX Star lasers. Cohort selection criteria were applied to select 911 eyes that underwent surgery between April 1, 1996 and October 1, 1997 in the range of study. Eyes with preoperative best spectacle-corrected visual acuity of worse than 20/40 (0.5) were excluded. Outcomes were stratified according to myopic treatment range. One day uncorrected visual acuity was 20/40 or better in 83% of eyes with both lasers. At 3 months, 20/40 uncorrected acuity was found in 93% of Summit and 90% of VISX eyes in the -1.00 to -4.00 D group, in 88% of Summit and 84% of VISX eyes in the -4.01 to -7.00 D group, and in 67% of Summit and 70% of VISX eyes in the -7.01 to -10 D group. Three-month manifest refractive outcomes in the -1.00 to -4. 00 D group were within +/- 1 D of target in 91% of the Summit eyes, and 89% of the VISX Eyes. In the -4.01 to -7.00 D range, 72% of the Summit eyes and 74% of the VISX eyes fell within +/- 1 D, and in the -7.01 to -10 D range, the rates were 53% for Summit and 56% for VISX. No eyes lost two lines or more acuity with either laser. Three-month visual and refractive outcomes in LASIK are comparable with the Summit Apex Plus and VISX Star lasers. Loss of BSCVA of two lines or more was not seen. CRS LASIK Study protocols are ongoing to provide longer follow-up and to study other refractive indications.