To evaluate the long-term outcomes of photorefractive keratectomy (PRK) in patients with mild to moderate keratoconus.

In this case series patients over 40 years, with bilateral grade I and II keratoconus (Krumeich classification) with no progression in the last two years were recruited. Cases with a predicted post-operative thinnest corneal location less than 450µ were excluded. Mitomycin-C was subsequently applied after PRK. The final endpoint was the last follow up visit (mean: 35 months).

Thirty-eight eyes of 21 patients were enrolled in this study. Twenty (52.6%) eyes were in grade I and eighteen (47.4%) eyes were in grade II of keratoconus. The mean uncorrected visual acuity, spherical equivalent refractive error (SE), cylindrical power and keratometry readings were significantly improved at the final endpoint compared to pre-operation measures (P<0.001). The best corrected visual acuity was lost for 2 lines in 2 eyes (5%) in the final follow up. No case of ectasia occurred during the follow up period.

PRK was proved to be a safe and effective procedure in improving the visual function of patients suffering from grade I and II keratoconus. However, careful patient selection is vital to avoid secondary progression of the disease.