Corneal Collagen Crosslinking for Keratoconus and Ectasia Using Riboflavin/Dextran or Riboflavin/Methylcellulose

- 12 years of age or older

- Having a diagnosis of keratoconus or corneal ectasia after corneal refractive surgery

- Presence of central or inferior steepening on the Pentacam map

- Axial topography consistent with keratoconus or post-surgical corneal ectasia

- Contact lens wearers only: removal of contact lens for the required period of 1 week prior to the screening refraction

- Signed written informed consent

- Willingness and ability to comply with schedule for follow-up visits

- Eyes classified as either normal, atypical normal, or keratoconus suspect on the severity grading scheme

- Corneal pachymetry less than or equal to 300 microns at the thinnest point measured by Pentacam in the eye(s) to be treated

- Previous ocular condition (other than refractive error) in the eye(s) to be treated that may predispose the eye for future complications, for example: History of corneal disease (e.g., herpes simplex, herpes zoster keratitis, recurrent erosion syndrome, corneal melt, corneal dystrophy, etc.) Clinically significant corneal scarring in the CXL treatment zone

- A history of chemical injury or delayed epithelial healing in the eye(s) to be treated

- Pregnancy (including plan to become pregnant) or lactation during the course of the study

- A known sensitivity to study medications

- Patients with nystagmus or any other condition that would prevent a steady gaze during the CXL treatment or other diagnostic tests

- Patients with a current condition that, in the investigator's opinion, would interfere with or prolong epithelial healing