Assessment of Intrastromal Corneal Ring Segment Position With Anterior Segment Optical Coherence Tomography

Abstract

To examine the exact position of implanted Keraring (Mediphacos, Belo Horizonte, Brazil) segments by high-resolution anterior segment optical coherence tomography (AS-OCT). This study included 17 eyes of 13 patients with keratoconus who underwent uneventful intracorneal ring segment implantation with the aid of femtosecond laser. Eyes were evaluated by AS-OCT at the third postoperative month. Distance from the apex of the triangular cross-section of the ring segment to the anterior corneal surface and distances from two basal corners to the posterior corneal surface were measured. Distance from apex to anterior corneal surface (263.1 ± 42.9 μm) was significantly smaller than target depth calculated intraoperatively (356.9 ± 35.7 μm, P < .001). Distance between outer basal corner and posterior corneal surface was significantly greater than distance between inner basal corner and posterior corneal surface. High-resolution AS-OCT is a rapid, convenient, and valuable technique in the follow-up of patients with implanted Keraring segments that may be helpful in predicting ring-related complications.