A low-energy femtosecond laser enabled predictable flap creation and a low retreatment rate for hyperopic LASIK with non-custom ablation, according to a study.
The prospective case series study included 800 eyes of 413 patients who underwent hyperopic LASIK where a femtosecond laser used for flap creation. Primary outcome measures were spherical equivalent, logMAR uncorrected and corrected distance visual acuity (UDVA/CDVA), defocus equivalent, intraoperative and postoperative complications, aberrometry and flap thickness. Follow-up visits occurred at 1, 4 and 30 days and 2, 4 and 9 months postoperatively.
The researchers found significant improvements at 9 months postoperatively in spherical equivalent, from +3.41 D preoperatively to –0.06 D, and defocus equivalent, from 4.2 D to 0.68 D. CDVA remained unchanged at 0.07.
The safety index was 1.0, indicating the procedure had a high level of safety, according to the researchers. Three eyes (0.4%) lost two lines of CDVA and 58 eyes (7.3%) lost one line. The efficacy index was 0.8. UDVA was 20/40 or better in 760 eyes (95%).
Mean root-mean-square induced primary spherical aberration was 0.65 µm. Mean induced primary coma was 0.24 μm. The researchers considered the increases in spherical equivalent and coma to be statistically significant.
Mean central flap thickness was 117.3 µm at 9 months.
No cases of flap dislocation or infection were reported. Three eyes had significant folds, six eyes had asymptomatic diffuse lamellar keratitis and six eyes had significant epithelial ingrowth, according to the researchers.
Nine eyes of seven patients underwent retreatment as a result of over- or under-correction.
Disclosure: The author has no relevant financial disclosures.