Purpose: To compare various methods of estimating corneal power for IOL calculation for cataract surgery after corneal refractive surgery.
Methods: Review of the medical literature and case reports.
Results: For more accurate IOL power calculations we need pre- (Kpre) and post-treatment keratometry records (Kpost) if using 3rd generation formulae, or Kpost records when using 4th generation formulae.
Conclusions: Prior to performing a keratorefractive procedure it is advisable to have pre-treatment refraction and keratometry (K and method) registered. 3rd generation formulae with Aramberri's double-K correction, or 4th generation formulae are recommended.