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Multistep photorefractive keratectomy for high myopia.

Nineteen human myopic eyes exceeding -8.00 D underwent multi-step excimer laser photorefractive keratectomy (PRK) with 6-month follow up. We performed two or three step PRK at the same time according to the amount of myopia present. The preoperative refraction ranged from -8.87 D to -16.99 D (mean -12.28 D). The mean attempted correction was 7.83 D. Six months after surgery, the mean refraction was -2.23 D. Keratometry demonstrated stable flattening of the cornea, and pachometry showed central cornea thinning. Seventeen eyes had clear or trace corneal haze. Above results showed multi-step PRK is a safe and relatively efficient procedure for correction of high myopia, but long-term follow up will be necessary to determine the stability of this procedure.