Changes in the total corneal refractive power after insertion of intrastromal rings in patients with keratoconus in short, medium and long term

ABSTRACT Objective To analyze the short, medium and long-term efficacy and stability in 46 eyes with keratoconus, operated with Ferrara intrastromal corneal ring segments. Methods The primary endpoint was the mean keratometry of total corneal refractive power. We also studied the effects of age, degree of keratoconus and clinical phenotype on the results, as well as the following keratometry variations and aberrometry variations: flattest, most curved, mean, maximum, astigmatism, root mean square of primary coma aberration and root mean square of secondary coma aberration. Results The immediate postoperative reduction in mean keratometry of total corneal refractive power was 3.08±1.51 diopters (D) (p