<prompt> All of the following are required for IOL power calculation before surgery except -BiometryKeratometrySRK FormulaCorneal topography  <response>: Intraocular lens power calculation :- Which requires Keratometry K, Axial length of eyebal or Biometry L and aconstant A. It is calculated by SRK formula:- Power of IOL A-25L-09K Ref: Fedorov SN, Kolinko AI. Estimaion of optical power of the intraocular lens. Vestn Oftalmol 1967; 80:27-31 