Corneal Shape Optimization Before Cataract Surgery: Topography-Guided Photorefractive Keratectomy In Eyes With Irregular Astigmatism

Irregular corneas present significant challenges to refractive predictability in cataract surgery. Surface ablation techniques, particularly topography-guided photorefractive keratectomy (PRK), have been shown to reduce corneal irregularity, improve visual acuity, and decrease higher-order aberrations in eyes with keratoconus and other causes of irregular astigmatism. This study evaluated the impact of preoperative corneal shape optimization on refractive accuracy and visual outcomes following cataract surgery.

A single corneal specialist’s refractive practice affiliated with the University of British Columbia, Vancouver, Canada.

This retrospective chart review included patients with irregular corneas who underwent topography-guided photorefractive keratectomy prior to cataract surgery between January 2022 and January 2026, with ≥6 months follow-up. Pre- and post-optimization biometric, refractive, and visual data were collected, including UCVA, BCVA, manifest refraction, keratometry, corneal topography (Pentacam), and wavefront aberrations (iTrace). Primary outcomes were refractive prediction error and corneal biometric stability; secondary outcomes included changes in higher-order aberrations, visual acuity, and visual aid dependence, including transition from contact lenses to spectacle independence.

Thirty-five eyes (26 patients; mean age 68 y) underwent topography-guided PRK 11.7 ± 5.5 months prior to cataract surgery for ectasia (n=24), post-LASIK HOAs (n=6), or corneal scarring (n=5). Postoperatively, RMS higher-order aberrations decreased from 0.63 to 0.49. Steep K improved from 46.9 ± 4.3 D to 44.7 ± 3.9 D and Kmax from 51.9 ± 5.5 D to 48.9 ± 3.4 D, remaining stable over 18.6 ± 8.4 months. IOLs included monofocal (16), toric (9), and EDOF (10). All eyes maintained or improved visual acuity; 86% were within ±0.50 D of target, and 94% of patients reported satisfaction. Rigid lenses were used by 14 patients (40%) preoperatively; postoperatively, none required rigid lenses, and three patients continued soft lens use.

Preoperative topography-guided PRK effectively regularises the corneal surface in eyes with irregular astigmatism, resulting in improved higher-order aberrations, enhanced refractive predictability, and high patient satisfaction following cataract surgery. Crucially, this approach successfully transitions patients out of requiring rigid gas-permeable (RGP) lenses. Corneal normalization prior to lens implantation is a valuable strategy for optimising refractive outcomes and reducing contact lens dependence in this complex patient population.