Seven RCTs were included (n=604 eyes, 302 patients). Methodological quality varied between studies: four studies were double-blind (n=336 eyes); two were single-blind (n=214 eyes); and one was open-label (n=214 eyes). Only two studies reported patient withdrawals or dropouts. Analyses were by intention-to-treat in all studies. Study durations ranged from three to 24 months.
Efficacy measures: At one month post-treatment, there was no statistically significant difference between LASEK and PRK groups in proportion of eyes with UCVA ≥20/20 (OR 0.93, 95% CI 0.45 to 1.93, p=0.85; four RCTs, 280 eyes). At 12 months post-treatment, there was no statistically significant difference between LASEK and PRK groups in proportion of eyes with UCVA ≥20/20 (OR 1.29, 95% CI 0.73 to 2.28, p=0.38; two RCTs, 240 eyes).
Accuracy measures: At one month post-treatment, there was no statistically significant difference between the two groups in proportion of eyes within ±0.50 dioptres of the target refraction (OR 1.23, 95% CI 0.81 to 1.89, p=0.33; four RCTs, 414 eyes). At 12 months post-treatment, there was no statistically significant difference between the two groups in proportion of eyes within ±0.50 dioptres of the target refraction (OR 1.59, 95% CI 0.88 to 2.88, p=0.12; two RCTs, 334 eyes).
Safety measures: No patient lost ≥2 lines of BSCVA at ≥6 months post-treatment (n=4 RCTs, 432 eyes).
Side-effects: There was no statistically significant difference between the two groups in mean pain scores (WMD -0.42, 95% CI -0.85 to 0.02, p=0.06; nine RCTs, 414 eyes). At six months post-treatment, there was no statistically significant difference between the two groups in mean corneal haze scores (WMD -0.17, 95% CI -0.36 to 0.02, p=0.07; four RCTs, 406 eyes). At 12 months post-treatment, there was no statistically significant difference between the two groups in mean corneal haze scores (WMD -0.06, 95% CI -0.17 to 0.06, p=0.33; three RCTs, 340 eyes).