Safety and Effectiveness of the PXL Platinum 330 System for Corneal Collagen Cross-Linking in Eyes With Corneal Thinning Position

Inclusion Criteria:Criterion 1,2,3 are required for all participants. Participants must also meet one or more of criteria 4-12. Criteria 13 is only relevant for contact lens wearers.

1. 12 years of age or older

2. Signed written informed consent

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

4. Presence of central or inferior steepening

5. Axial topography consistent with keratoconus, post-surgical ectasia, or pellucidmarginal degeneration

6. Presence of one or more findings associated with keratoconus or pellucid marginaldegeneration, such as

7. Fleisher ring

8. Vogt's striae

9. Decentered corneal apex

10. Munson's sign

11. Rizzutti's sign

12. Apical corneal scarring consistent with Bowman's breaks

13. Scissoring of the retinoscopic reflex

14. Crab-claw appearance on topography

15. Steepest keratometry (Kmax) value greater than or equal to 47.2

16. I-S keratometry difference < 1.5 D on the Pentacam map or topography map

17. Posterior corneal elevation > 16 microns

18. Thinnest corneal point <485 microns

19. Predicted Post LASIK/PRK stromal ablation depth <350 microns or expected keratometry >47.2, or patients undergoing PRK/SMILE in keratoconus suspect eyes

20. Bacterial or fungal keratitis persistent and not responding despite > 2 weeks ofstandard antimicrobial therapy or with rapid progression of corneal thinning, withloss of >25% corneal thickness

21. Contact lens wearers only:

22. Removal of contact lenses for the require period of time prior to the screeningrefraction:

Contact Lens Type Discontinuations Time: Soft, 1 week; Soft Extended Wear, 2 weeks; Soft Toric, 3 weeks; Rigid Gas Permeable, 2 weeks per decade of wear -

Exclusion Criteria:

1. Eyes classified as normal or atypical normal on the severity grading scheme

2. Corneal pachymetry at the screening exam that is <300 microns at the the thinnestpoint in the eye(s) to be treated.

3. Previous ocular condition (other than refractive error) in the eye(s) to be treatedthat may predispose the eye for future complications, for example:

4. History of or active corneal disease (e.g. herpes simplex, herpes zosterkeratitis, recurrent erosion syndrome, acanthamoeba, etc.)

5. Clinically significant corneal scarring the CXL treatment zone that is notrelated to keratoconus or, in the investigator's opinion, will interfere withthe cross-linking procedure.

6. Pregnancy (including plan to become pregnant) or lactation during the course of thestudy

7. A known sensitivity to the study medications

8. Patients with nystagmus or any other condition that would prevent a steady gazeduring the CXL treatment of diagnostic tests.

9. Patients with a current condition that, in the physician's opinion, wold interferewith or prolong epithelial healing.