Experience With 340-Degree Intrastromal Ring Segment
To evaluate visual and refractive outcomes in keratoconus patients implanted with a 340-degree intrastromal ring segment (ICRs).
Contact lens-intolerant patients (≥18 years) with advanced central or paracentral zone keratoconus (Grade I, II and III) underwent implantation with the Keraring 340-degree ICRs (Mediphacos Ltda). All patients underwent refractive assessment and corneal topography preoperatively and postoperatively, including measurement of uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), mean keratometry (Kmean), spherical equivalent (SE) and cylindrical refraction.
In this prospective case series, 7 patients (11 eyes) with topographic nipple cone keratoconus were included. The mean age was 22±2.2 years. There were improvements postoperatively vs. preoperatively in mean UCVA (0.4±0.2 vs 0.05±0.01 ), mean BCVA (0.5±0.14 vs. 0.24±0.2 ) mean cylindrical refraction (-2.25±0.2 vs. -4.38±0.8 D), and mean SE (-3.24±0.42 vs -9.26±1.2 D). There was also a reduction in Kmean (45.6 postoperatively vs 53.7 preoperatively).
Implantation of the 340-degree ICRs is an effective and a safe method for the improvement of UCVA and BCVA in central or parcentral cone keratoconic eyes.