The purpose of this study is to assess safety, efficacy and stability of riboflavin-UV induced cross-linking of corneal collagen in reducing the progression of keratecatasia and in improving visual acuity. This is the first Norwegian study concerning CCL.

The technique of corneal collagen cross-linking consists of photopolymerization of stromal fibers by combined action of a photosensitizing substance, riboflavin and ultraviolet type A rays (UVA) from a solid-state UVA Source. Photopolymerization increases the rigidity of corneal collagen and its resistance to keratectasia. It has been used to stop progression of keratectasia.

Corneal transplantation has been the only available option so far for treatment for keratectasia in its advanced stage in Norway. The method of CCL using riboflavin and UV light is technically simple and much less invasive than corneal transplantation and it treats and prevents the underlying pathophysiological mechanism. It also does not reduce the chances for a successful corneal transplantation, in case that would still be necessary after CCL.

The purpose of this study is to assess safety, efficacy and stability of riboflavin-UV induced cross-linking of corneal collagen in reducing the progression of keratecatasia and in improving visual acuity. This is the first Norwegian study concerning CCL.

Inclusion Criteria:

1. Age from 20 to 45 years
2. Progressive keratectasia (primary or secondary) in an advanced stage
3. Decreased best corrected visual acuity bellow 20/40, which cannot be further improved by use of soft contact lenses
4. Rigid contact lenses are either not tolerated or do not improve visual acuity
5. No previous eye surgery (except for laser refractive surgery)
6. All patients must provide written informed consent to become a study subject
7. Subjects able to return for scheduled follow-up examinations according to this protocol

Exclusion Criteria:

1. Corneal thickness < 400 µm at thinnest position
2. Keratometric - readings above 60 diopters
3. Other active ocular disease than keratectasia
4. Herpes keratitis
5. Previous ocular surgery (other than laser refractive surgery)
6. Patients who were immunocompromised, pregnant or who had atopic syndrome, connective tissue or autoimmune disease
7. Patients with known sensitivity to study medication
8. Subjects with intraocular pressure > 23 mmHg by Goldmann applanation tonometry, a history of glaucoma, or glaucoma suspects
9. Subjects who intent to participate in other ophthalmic clinical trails during this clinical investigation