Incidence of posterior vitreous detachment after three different types of laser refractive surgery

To compare the incidence of posterior vitreous detachment (PVD) after small incision lenticule extraction (SMILE), femtosecond laser in situ keratomileusis (FS-LASIK), and transepithelial photorefractive keratectomy(T-PRK), and to evaluate its potential risk factors and association with early postoperative visual and refractive outcomes.

Patients who met the eligibility criteria for SMILE, FS-LASIK, or T-PRK after comprehensive preoperative evaluation were enrolled. B-scan ultrasonography was performed by a single operator one day before surgery, and patients with preoperative PVD were excluded. Finally, 24 patients (45 eyes) were included in the SMILE group (Group S), 21 patients (39 eyes) in the FS-LASIK group (Group F), and 22 patients (44 eyes) in the T-PRK group (Group T). All procedures were performed by the same surgeon. B-scan ultrasonography was repeated by the same operator 1 week after surgery to detect newly developed PVD.

The mean age was 21.5 ± 5.56 years, 23.9 ± 5.00 years, and 22.9 ± 4.56 years in Groups S, F, and T, respectively (p = 0.484). The mean axial length was 25.80 ± 0.87 mm, 25.91 ± 0.80 mm, and 25.72 ± 0.94 mm, respectively (p = 0.603), and the mean spherical equivalent was -4.65 ± 1.49 D, -5.33 ± 1.79 D, and -4.70 ± 1.36 D, respectively (p = 0.080). Postoperative PVD was detected in 9 eyes in Group S (20.0%; 95% CI, 9.6%-34.6%), 7 eyes in Group F (17.9%; 95% CI, 7.5%-33.5%), and 5 eyes in Group T (11.4%; 95% CI, 3.8%-24.6%) (p = 0.570).

No statistically significant difference in early postoperative PVD incidence was observed among SMILE, FS-LASIK, and T-PRK within one week after surgery. Further studies with larger sample sizes and longer follow-up are needed to confirm these findings.