Radial keratotomy for the optical rehabilitation of mild to moderate keratoconus: more than 5 years' experience.

PURPOSE To present the authors' long-term experience of radial keratotomy (RK) for the optical rehabilitation of patients with mild to moderate keratoconus--central corneal thickness of greater than 400 microm and without apical scarring. METHODS In this observational, noncomparative series of cases, all consecutive patients with mild or moderate keratoconus, treated by RK between 1990 and 2002, with at least 1 year follow-up were included. A total of 170 eyes of 96 patients were investigated. Mean follow-up was 42.08 +/- 28.14 months. Visual acuity, refraction, corneal curvature, central corneal thickness, and complications were evaluated. RESULTS In all of the control visits, mean uncorrected and best spectacle corrected visual acuities were better than preoperative values (p<0.0001). Preoperative myopic spherical refraction decreased significantly (p<0.0001), and remained relatively unchanged throughout the follow-up (p=0.43). A small but statistically significant decrease from baseline was ob-served in astigmatism (p=0.038), which almost disappeared 1 year after the surgery (p=0.47). The surgery produced a statistically significant flattening of the corneal curvature (p<0.0001). Central corneal thickness did not change significantly (p>0.05) in either control visit. In 33 eyes (19.4%), re-deepening of the incisions was required. In 3 eyes (1.8%) penetrating keratoplasty was performed, due to disease progression in 2 eyes (1.2%) and acute traumatic hydrops in 1 eye (0.6%). In 4 eyes (2.2%) microperforation, in 2 eyes (1.2%) macroperforation, in 1 eye (0.6%) infectious keratitis, and in 1 eye (0.6%) hyperopic shift occurred. CONCLUSIONS RK surgery was found to be a reasonable option for the rehabilitation of a selected group of keratoconus patients in the early or moderate stages.