Simulated Keratometry Versus Total Corneal Power by Ray Tracing: A Comparison in Prediction Accuracy of Intraocular Lens Power

Purpose: To investigate the relationship between corneal powers measured by simulated keratometry (Sim-K) and ray tracing and understand whether their difference influences intraocular lens (IOL) power calculation. Methods: In a first sample of healthy eyes, corneal curvature was measured using a rotating Scheimpflug camera (Sirius, CSO). Sim-K was obtained from anterior corneal curvature using the 1.3375 keratometric index. Ray tracing was performed through both corneal surfaces to calculate the total corneal power (TCP). The difference between Sim-K and TCP was correlated with various parameters. In a second sample of patients undergoing cataract surgery, IOL power was subsequently calculated using both Sim-K and TCP. Results: In the first sample (114 eyes), Sim-K (43.64 ± 1.44 D) was higher than TCP (43.07 ± 1.41 D, P
Source: Cornea - Category: Opthalmology Tags: Clinical Science Source Type: research