Topography-guided surface ablation for forme fruste keratoconus

Purpose: To evaluate the efficacy of customized surface ablation in cases of forme fruste keratoconus. Design: Prospective noncomparative case series. Participants: Eleven eyes of 8 contact lens-intolerant patients with forme fruste keratoconus treated at the Institute of Refractive and Ophthalmic Surgery and the University Eye Clinic Zurich. Intervention: Topography-guided customized surface ablation by means of a scanning spot excimer laser. Main Outcome Measures: Visual acuity, refraction, quality of vision (ghosting), corneal topography including the Zernike parameter Z3. Results: Statistically significant reduction of manifest refractive error, corneal irregularity, and ghosting. The spherical equivalent was reduced by -2.8 +/- 0.62 diopters (D) (P = 0.0007), the cylinder by 1.34 +/- 0.18 D (P = 0.015), Z3 was reduced by 41% (P < 0.001), and all patients had less ghosting compared to their preoperative status. No eye lost >= 1 lines in best spectacle-corrected visual acuity; however, 7 of 11 eyes gained >= 1 line. Conclusion: Topography-guided surface ablation is a promising option to rehabilitate vision in contact lens-intolerant patients with forme fruste keratoconus.