Correlation Factors for Posterior Corneal Curvature after Myopic LASIK

Objective: To evaluate the correlation factors for the posterior corneal curvature after myopic LASIK. Methods: The retrospective study of 92 eyes which underwent myopic LASIK was conducted. All LASIK procedures were done using Hansatome® Microkeratome and Tecnolas® 217 excimer laser (B&L, USA). Pre- and post-operative data were collected including refraction, corneal thickness, anterior and posterior corneal curvature measured by Orbscan® Corneal Topography. Statistical analysis was done to evaluate the posterior corneal curvature related to other factors. Results: The posterior corneal curvature after myopic LASIK showed no correlation to anterior corneal curvature (R2 = 0.0036). It also showed low to moderate correlation to amount of myopia treated (R2 = 0.286) and corneal thickness (R2 = 0.37 for measured corneal thickness and R2  0.40 for calculated corneal thickness which is calculated by subtract ablation depth from pre-operative thickness) (all p value < 0.05). Conclusion: The posterior corneal curvature after myopic LASIK can be partially correlated with corneal thickness, anterior corneal curvature and amount of myopia treated.