[Comparison of posterior vitreous detachment after femtosecond laser and microkeratome-assisted lase in situ keratomileusis].

OBJECTIVE

To compare the incidence of posterior vitreous detachment (PVD) early after femtosecond laser and microkeratome-assisted LASIK and their changes after follow-up observation.

METHODS

It was a prospective study. According to the choices of the patients, 40 cases (80 eyes) underwent femtosecond laser (INTRALASE FS 60, Abbott Medical Optics, American) LASIK surgery in the femtosecond group and 40 cases (80 eyes) underwent microkeratome-assisted (AMADEUS II, Ziemer, Switzerland) LASIK surgery in the microkeratome group. The occurrence of PVD was observed by B ultrasound and OCT examination pre- and 1 week, 1, 3 and 6 months post-operatively. Data from one eye in each patient were randomly selected for statistical analysis. Independent sample χ(2) test was used to compare postoperative PVD between these two groups. Multiple logistic regression was used to investigate the association of PVD changes with age, gender, eye, axial length, refraction, IOP, corneal thickness and suction time.

RESULTS

In femtosecond group, 18 eyes (45.0%) had partial PVD before surgery. In 11 eyes (27.5%), PVD developed in non-PVD eye or PVD increased in eyes already had PVD preoperatively. In microkeratome group, 21 eyes (52.5%) had partial PVD preoperatively. In 8 eyes (20.0%), PVD developed in non-PVD eyes or PVD increased in eyes already had PVD preoperatively. There was no statistically significant difference between these 2 groups (χ(2) = 2.257, P = 0.133). Logistic regression analysis indicated that the suction time was associated with the postoperative development of PVD in femtosecond group (OR = 1.089, P = 0.027) and long axial length was a significant risk factor for the development of PVD in microkeratome group (OR = 4.712, P = 0.007). No serious posterior segment complications such as retinal breaks or retinal detachment were observed postoperatively.

CONCLUSIONS

INTRALASE FS 60 femtosecond laser does not increase the incidence of PVD compared to AMADEUS II microkeratome-assisted LASIK. PVD is more likely to occur in eyes with long axial length. No serious posterior segment complications were observed during the 6 month follow-up period.