[Incidence of vitreoretinal pathologic conditions in myopic eyes after laser in situ keratomileusis].

OBJECTIVE: To determine the incidence of vitreoretinal pathologic conditions in myopic eyes after laser in situ keratomileusis.

METHODS: Vitreoretinal pathologic conditions of 1981 consecutive eyes (995 patients) having undergone laser-assisted in situ keratomileusis for the correction of myopia were studied. Preoperative and postoperative basic examinations included visual acuity, manifest and cycloplegic refraction, slit-lamp microscope examination, applanation tonometry and a fundus examination after pupil dilatation by indirect ophthalmoscopy and biomicroscopy with spherical lens of + 90 diopters. Before laser in situ keratomileusis, preventive treatment was carried out for predisposing lesion of retinal detachment in 8 eyes: 6 eyes for lattice degeneration and 2 eyes for atrophic holes. Postoperative examinations were conducted at 1, 3 and 12 months and once a year thereafter. All eyes were followed up for >/= 12 months.

RESULTS: Eyes were followed for a mean of (18.40 +/- 4.50) months (range 12 - 28) after the surgery. Sixteen eyes of 13 patients (0.81%) developed vitreoretinopathy after LASIK, including 6 eyes with lattice degeneration (0.30%) in which one of them had previous laser treatment, 2 with posterior vitreous detachment (0.10%), 2 with macular hemorrhage (0.10%), 4 with rhegmatogenous retinal detachment (0.20%), and 2 with retinal tear without retinal detachment (0.10%) in which one of them had previous laser treatment for lattice degeneration. Five patients were males (5 eyes involved). Others were females. Mean age of the group with vitreoretinal pathologic conditions was 31.80 +/- 5.85 years (range 22 to 43). The interval between refractive surgery and development of vitreoretinal complication was (10.38 +/- 6.20) months (range 1 to 24). The eyes that developed vitreoretinopathy had myopia -4.75 to -15.00 diopters (mean -9.45 +/- 2.61 D) before LASIK. The comparison of incidences of vitreoretinopathy after LASIK between the group of >/= -6.00 D and < -6.00 D before surgery showed significant difference (P < 0.01, chi(2) = 60.78). The comparison of incidences of vitreoretinopathy after LASIK had also significant difference (P < 0.01, chi(2) = 138.64) between the eyes with pre-LASIK lattice degeneration and dry hole and eyes without such lesions. The cases of lattice degeneration and retinal tear were treated with laser retinopexy. All cases of rhegmatogenous retinal detachment were managed with cryoretinopexy and scleral buckling. Retinal reattachment was attained in all eyes and good visual acuities were recovered.

CONCLUSION: No direct cause-effect relationship between LASIK and vitreoretinopathy can be proven from this study. Although the incidence of vitreoretinal pathologic conditions in myopic eyes after laser in situ keratomileusis is low, it is necessary to strictly filter candidates. Preoperatively and postoperatively, pay attention to the lattice degeneration and other retina lesions, and long-term follow-up is important.