Barrett, Graham D.

Keratoconus is a progressive ectatic corneal disease characterized by corneal thinning, steepening, and irregular astigmatism, presenting unique challenges for intraocular lens (IOL) calculations in cataract surgery. The use of traditional formulas for IOL calculations in eyes with keratoconus frequently leads to significant refractive prediction errors, often resulting in a hyperopic shift, which can lead to suboptimal outcomes and reduced patient satisfaction. This review examines the impact of keratoconus on IOL calculations and highlights recent advancements in formulas specifically designed for eyes with keratoconus, particularly the Barrett True-K and the Kane Keratoconus formulas. We assess the effectiveness of these formulas based on the current literature and provide clinical recommendations aimed at improving surgical outcomes in this complex patient group.