LASIK & PRK: still looks good ten years on

LASIK for myopia over -10 D is a safe procedure; myopic regression slows down with time and there is a high rate of best spectacle corrected visual acuity (BSCVA) increase in the long-term, according to Jorge Alio, MD and colleagues from the VISSUM Instituto Oftalmológico de Alicante and the Miguel Hernandez University Medical School, Spain.

A total of 196 myopic eyes (118 patients) with a mean preoperative spherical equivalent (SE) of -13.95±2.79 D were included in the study. Myopic LASIK was performed using the VISX 20/20 excimer laser (AMO) with a 6 mm ablation zone. Patients were evaluated at three months, one, two, five and 10 years.

At 10 years follow-up, 82 eyes (42%) were within ±1.00 D and 54 eyes (27.5%) had undergone re-treatments. The mean SE decreased, in eyes that did not receive re-treatments, with a mean rate of -0.25±0.18 D per year that slowed over time. Overall, 124 eyes (63%) demonstrated an increase in BSCVA after 10 years follow-up. Two eyes (1%), with more than 15 D myopic correction, developed corneal ectasia.

…and so does PRK

The same research team also claimed that photorefractive keratectomy (PRK) for myopia over -10 D is a safe procedure with a high rate of BSCVA increase in the long term.

In a further study, 70 eyes (50 patients) with myopia ranging between -10.00 and -17.75 D underwent myopic PRK with the VISX 20/20 excimer laser (AMO) with a 6 mm ablation zone and were followed-up for a ten-year period.

Twenty-eight eyes (40%) were within ±1.00 D at 10 years follow-up and 28 eyes (40%) underwent re-treatments. Mean SE decreased over 10 years at a rate of 0.23±0.30 D per year that slowed down with time. Forty-one eyes (58%) demonstrated an increase in BSCVA after 10 years and only five (7.1%) lost more than two lines of BSCVA. The mean corneal haze score decreased gradually from 0.87±0.83 at three months to 0.16±0.45 at 10 years.

The authors of these two studies suggest that both LASIK and PRK are safe and effective procedures for the correction of high myopia.