Actorial analysis research of the changes of posterior cornea curvature after laser in situ keratomileusis of patients with High myopia

Objective Observe the changes of posterior cornea curvature after laser in situ keratomileusis(LASIK).Study the relationship of posterior cornea curvature change with preoperative intraocular pressure and load factor(Preoperative corneal thickness/Residual bed thickness).Methods Forty patients(80 eyes) were treated by LASIK.Curve of corneal posterior surface was measured with Orbscan II topography system before and 1 month,2 month,3 month,6 month after surgery.The results of measurement in different time points were compared.Patients were divided into four groups according to the preoperative intraocular pressure and load factor.Study the relationship of posterior cornea curvature change with preoperative intraocular pressure and load factor.Results The posterior corneal surface showed a mean forward shift after LASIK of patients with high myopia.1 month after LASIK surgery,radius of posterior cornea curvature were changed 0.135 μm ±0.098 μm,2 month after LASIK surgery,radius of posterior cornea curvature were changed 0.022 μm±0.034μ m.Cconclusion The posterior corneal surface showed a mean forward shift after LASIK with high myopia,2 months after LASIK surgery corneal surface curvature basically stable.The higher the preoperative intraocular pressure,the bigger the load factor,the more obvious the forward shift of the cornea.