Cataract surgery in keratoconus: current challenges and future directions

Cataract surgery in keratoconus remains one of the most challenging settings in anterior segment surgery. This review summarizes recent evidence (2020-2025) on intraocular lens (IOL) power calculation, surgical strategies, and adjunctive treatments, highlighting current limitations and future perspectives.

Advances in keratoconus-specific formulas such as Barrett True-K and Kane-KC, particularly when posterior corneal curvature is measured, have improved refractive accuracy compared with conventional formulas, though prediction errors remain higher than in normal eyes. Toric IOLs are effective in carefully selected mild-to-moderate cases, with multimeasurement calculators improving astigmatic prediction and a 2025 systematic review confirming safety and stability. Small-aperture optics (IC-8) may increase depth of focus, but keratoconus-specific evidence is limited. Staged approaches, including intracorneal ring segments, cross-linking, and DALK in advanced disease, improve safety and predictability. Emerging technologies such as artificial intelligence-based calculators and premium IOLs show promise but require further validation.

Despite significant progress, outcomes in keratoconus remain less predictable than in normal eyes. Careful patient selection, keratoconus-adjusted formulas, and staged surgical strategies are essential. Future priorities include prospective validation of formulas, integration of artificial intelligence tools, and evaluation of adjustable optics.