The Value Of The Posterior To Anterior Corneal Refractive Ratio And Its Dependence On The Value Of Ablation In Patients After Laser Vision Correction.

The aim of this study is to determine the difference between the values ​​of the ratio of the posterior and anterior surface of the cornea (B/F ratio) and its dependence on the value of ablation in patients before and after laser vision correction. Determining this value helps us in the calculation of intraocular lenses before lens exchange. 

Lexum eye clinic, Brno, Czech Republic, Optegra group 

Masaryk University, Faculty of Medicine, ​Department of Optometry and Orthoptics​, Brno, Czech Republic 

The retrospective study was conducted from April 2024 to February 2025 at the Lexum Eye Clinic in Brno and included a total of 100 eyes. The measurements were done on Pentacam (Oculus Inc) and MS-39 (CSO). Postoperative results are recorded one and three months after the laser vision correction (LVC) procedure. Included LVC procedures are Femto-LASIK, PRK and ReLEx Smile. 

The results show that one month after laser refractive surgery, the correlation between the B/F ratio and ablation was r = 0.91. Comparison between measurements from two different devices and between first- and third-month postoperative values ​​will be further evaluated with additional data. 

The change in the ratio of posterior to anterior corneal refraction before and after surgery is directly proportional to the value of laser ablation. The correlation coefficient is significant. With this finding, we can refine further IOL calculation in patients after LVC.