Refractive Surgery Feature Story

JUNE 2010 CATARACT & REFRACTIVE SURGERY TODAY EUROPE 23 A s we reported in the Journal of Cataract and Refractive Surgery,1 use of a thick intrastromal corneal ring segment (ICRS) may enhance the surgical effect in patients with keratoconus. Although commercially available ICRSs are limited in thickness, one can achieve the effect of thicker segments by stacking two within a single intrastromal tunnel. The case study presented below suggests that considerably thicker segments may be a beneficial treatment for keratoconus and that a double-stacked configuration of two thin segments may be better tolerated than a single, thick segment. In October 2008, a 45-year-old man with keratoconus presented to our clinic complaining of poor BCVA and contact lens intolerance. His BCVA at that time was 20/200 in the right eye and 20/20 in the left. Slit-lamp examination of the right eye revealed central thinning, Vogt striae, and inferior corneal steepening without scarring, consistent with a diagnosis of asymmetric keratoconus. Topography, pachymetry, and posterior elevation maps of the right eye (Pentacam; Oculus Optikgeräte GmbH, Wetzlar, Germany) revealed an inferotemporally displaced cone with central keratometry (K) readings greater than 65.00 D (Figure 1).