Intrastromal corneal ring technology: results and indications.

Intracorneal ring technology has shown rapid development in the past 10 years, and clinical results are confirming outstanding results for the correction of low to moderate refractive myopias. Two of these device designs, the Intrastromal Corneal Ring and the Intrastromal Corneal Ring Segments (both manufactured by KeraVision, Inc., Fremont, CA) are currently undergoing rigorous investigation in US Food and Drug Administration-regulated clinical trials. Results to date indicate the surgical procedure is safe and easily performed, the visual results are excellent (preserving best spectacle-corrected visual acuity), and the procedure provides stable and predictable correction through several years postoperatively. Preliminary results show that enhancements can be easily performed by device exchange, and the device can be removed, reversing the refractive effect.