This is a compassionate treatment protocol for the use of the UV-X system for corneal collagen cross-linking (CXL) in eyes with progressive keratoconus in patients who have conditions that limit their capacity to comply with the cross-linking treatment procedures required by ongoing clinical trials.

This is a non-randomized study. All eyes that qualify for the study will receive the cross-linking (CXL) procedure. Corneal collagen cross-linking is performed as a single treatment. Depending on the patient's condition, the CXL procedure may be performed under sedation or anesthesia. Subjects are followed for 12 months after the procedure to evaluate the long term effects of corneal collagen cross-linking.

Inclusion Criteria:

• Age 6 to 18 years
• Having a diagnosis of progressive keratoconus
• Signed written informed consent
• Having a condition that limits the patient's capacity to comply with the cross-linking treatment procedures and/or the diagnostic tests and measurements required by the ongoing clinical studies
• Willingness and ability to comply with schedule for follow-up visits

Exclusion Criteria:

• Corneal pachymetry at the screening exam that is <400 microns at the thinnest point
• Previous ocular condition in the eye(s) to be treated that may predispose the eye for future complications, for example (herpes simplex, herpes zoster keratitis, recurrent erosion syndrome, corneal melt, or corneal dystrophy, etc.)
• A history of delayed epithelial healing in the eye(s) to be treated
• Pregnancy or lactation during the course of the study
• A known sensitivity to study medications