Aim: To evaluate the results of LASIK re-treatment for under correction or regression after primary LASIK procedures for myopia and myopic astigmatism.
Methods: A prospective evaluation of 360 consecutive LASIK-treated eyes, for myopia and/or myopic astigmatism, 32 eyes of 34 patients were retreated and followed at 3, 6 and 12 months post retreatment. Re-treatment was performed by lifting the original flap after cutting the epithelium around the flap edge with a fine needle. Standard ablation was performed based on the patient’s residual refraction.
Results: 9.4% of eyes patients required retreatment. Prior to re-treatment the mean manifest spherical equivalent (SE) was –0.99 D ± 1.48 D (range from - 0.75 to -2.63). The mean sphere was - 0.79 D ± 1.20 D (range from –2.50 to -0.50) and the mean cylinder was –0.90 D ± 1.14 D (from –2.75 to 1.25). At 1 year follow up 56% of the eyes were within ± 0.50 D SE and 78% were within ± 1.00 D SE. 78% percent of the eyes examined at one year post re-treatment managed unaided vision of 6/9 or better. Peripheral epithelial ingrowth not requiring treatment, developed in two eyes. Second re-treatment for regression was performed in one eye. A significant correlation was found between the refractive regression and each of the following: preoperative refraction, attempted correction and ablation depth
Conclusion: LASIK re-treatment for residual myopia, by lifting the original flap is an effective option. Refractive results are fairly predictable and refraction stabilizes by 3 months after re-treatment. Lifting the corneal flap after cutting the epithelium on the flap edges, is easy to perform and has a very low incidence of epithelial ingrowth.