Pentacam Findings After Implantation of Intrastromal Corneal Rings in Keratoconus.

keratoconus is a progressive corneal ectatic disease characterized by paraxial stromal thinning and weakening, resulting in irregular astigmatism, corneal protrusion, and distortion of the anterior corneal surface. It is usually bilateral, although asymmetrical in most cases. Intrastromal corneal rings are polymethylmethacrylate devices successfully used for the management of keratoconus, pellucid marginal degeneration, post-LASIK ectasia and myopia. Intrastromal corneal rings implantation is safe and reversible procedure that does not affect the central corneal area, and hence, avoids interference with visual axis. The goal of intrastromal corneal rings implantation is to improve visual acuity by regulariztion of the anterior corneal surface.