Study examines outcomes of LASIK, PRK at 10 years

J Refract Surg. 2010;26(3):168-176.

LASIK and PRK have been shown to be similarly effective in the long-term treatment of more than 10 D of myopia, but PRK is associated with a longer recovery time, a study showed.

However, LASIK is no longer routinely indicated for myopia of 10 D or more, and PRK is no longer performed to treat high myopia because of potential postoperative complications such as haze, the study authors said. PRK is typically indicated for myopia of less than 6 D.

"No study in the literature currently compares the long-term refractive outcomes of LASIK and PRK in the treatment of high myopia," the authors said.

The retrospective study included 51 eyes that underwent PRK and 141 eyes that underwent LASIK for high myopia between 1992 and 1995. All eyes underwent long-term assessment at 10-year follow-up. PRK patients had a mean age of 33.96 years, and LASIK patients had a mean age of 32.44 years.

PRK patients had a mean preoperative spherical equivalent refraction of -12.44 D and best corrected visual acuity of 0.50. LASIK patients had a mean preoperative spherical equivalent of –12.81 D and BCVA of 0.56.

Study data showed that 10 years after surgery, 45.5% of eyes in the LASIK group and 31.3% of eyes in the PRK group had uncorrected visual acuity of 20/40 or better. The mean efficacy indices were 0.87 in the LASIK group and 0.82 in the PRK group; the difference was not statistically significant.

Both groups had statistically similar regression: –1.49 D in the LASIK group and –1.28 D in the PRK group.

Results showed that 60 eyes in the LASIK group and 21 eyes in the PRK group were within 1 D of targeted refraction at 10 years.

Six eyes in the PRK group and seven eyes in the LASIK group lost two or more lines of BCVA, the authors said.

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