LASIK for high myopia found stable at 11 years in small study

The refractive stability achieved 6 months after LASIK for high myopia appears to be maintained at 11 years follow-up, according to a small study by researchers in Greece.

George D. Kymionis, MD, PhD, and colleagues at the University of Crete reviewed the stability and complications of LASIK at 11 years postop in 11 eyes of seven patients treated for high myopia. All surgeries were performed with a Draeger lamellar rotor keratome (Storz Instruments) and the 193 nm MEL 60 excimer laser (Carl Zeiss Meditec), according to the study.

Patients had a mean preoperative spherical equivalent of –12.96 D. At 11 years follow-up, the mean spherical equivalent error had been significantly reduced to –1.14 D (P < .001), the authors said. Patients achieved refractive topographic stability at 6 months and experienced no significant changes over the course of follow-up. At 6 months, spherical equivalent averaged –0.96 D vs. –1.14 D at 11 years (P = .36), according to the study.

Surgeons attempted a mean spherical correction of –12.59 D, and at 11 years postop six eyes (55%) were within –1 D of intended correction, the authors noted.

The amount of correction achieved also did not significantly change between 6 months and 11 years, averaging 11.52 D at 6 months and 11.36 D at 11 years (P = .38), they added.

The 6-month delay in achieving refractive stability "could be mainly because of the increased amount of attempted corrections in the study," the authors said. "It is known that after high attempted myopic corrections, it takes longer for [the] refraction to stabilize than after smaller corrections."

No patients experienced any long-term complications, although three patients suffered postoperative astigmatism from poorly cut flaps or decentered ablations. Night vision problems, such as halos, were reported in 82% of eyes, the authors noted.

"No late postoperative complications occurred ... and there was no evidence of cataract formation," they said.

Five patients, representing 73% of eyes in study, reported that they were "extremely satisfied" with their visual results at 11 years follow-up. The other two patients were unhappy due to residual refractive errors, loss of visual acuity and subjective visual problems, according to the study.

The study is published in the February issue of the Journal of Cataract & Refractive Surgery.