Purpose: Anterior corneal radius is a crucial parameter in the double-K method to calculate intraocular lens power for post-refractive cases. This research aimed to develop a method to estimate anterior corneal radius before corneal laser refractive surgery using the postoperative corneal parameters.
Methods: Corneal parameters of normal eyes were investigated by Pentacam Scheimpflug camera. The correlation between anterior and posterior corneal radii (Ra and Rp) was evaluated by statistical means.
Results: An algorithm using postoperative Rp to calculate Ra before refractive surgery was developed: Ra=0.82*Rp+2.53(r=0.86, P<0.01). The algorithm was used to calculate Ra for patients after corneal laser refractive surgery. The calculated preoperative Ra was well correlated the actual preoperative Ra, r=0.88,P<0.01. No difference was found between the calculated and actual Ra (paired sample t test, p=0.36).
Conclusion:The algorithm of using postoperative Rp to estimate Ra before laser refractive surgery is reliable and can be used in double-K method for intraocular lens power calculation for post-refractive cataract cases.