IOL Power Calculation in Keratoconus

The changes in the keratoconic cornea affect multiple aspects of IOL power calculation. The challenges with keratoconus are the corneal power measurement issues, the IOL formula calculation errors, and the difficulty in refraction. The different formulas used in keratoconus cases are compared. The Kane keratoconus formula utilises modified anterior corneal radii of the curvature that better represents the true anterior/posterior ratio in keratoconic eyes while also minimising the effect of corneal power on the ELP calculation. The Barrett True K formula for keratoconus incorporates the posterior corneal power and central corneal thickness to improve post-operative prediction. The SRK/T was better than all other conventional formulas.