Safety and Effectiveness of the PXL-Platinum 330 System for Cornea Crosslinking in Eyes With Cornea Thinning

Inclusion Criteria

• healthy subjects with no other medical or ocular conditions

Subjects who have one or both eyes that meet criteria 1 and 1 or more of the following criteria will be considered candidates for this study:

• 18 years of age or older
• Presence of central or inferior steepening (on Pentacam topograph)
• Axial topography consistent with keratoconus, post-surgical ectasia, or pellucid marginal degeneration (See keratoconus grading section 7.0 for details)
• Presence of one or more findings associated with keratoconus or pellucid marginal degeneration on slit lamp exam such as:

• Fleischer ring
• Vogt's striae
• Decentered corneal apex
• Munson's sign
• Rizzutti's sign
• Apical Corneal scarring consistent with Bowman's breaks
• Scissoring of the retinoscopic reflex
• Crab-claw appearance on topography
• Steepest keratometry (Kmax) value ≥ 47.20 D on simK or Pentacam
• I-S keratometry difference > 1.5 D on the Pentacam/Galilei/Orbscan/Cassini map or topography map
• Posterior corneal elevation >16 microns (µm on Pentacam tomography)
• Thinnest corneal point \<485 microns (ultrasound pachymetry or Pentacam tomography)
• Predicted Post LASIK/PRK stromal ablation depth \<350 microns or expected keratometry >47.2 D, or patients undergoing PRK/SMILE in keratoconus suspect eyes
• Bacterial or fungal corneal keratitis persistent and not responding despite > 2 weeks of standard antimicrobial therapy or with rapid progression of corneal thinning, with loss of >25% corneal thickness
• Contact Lens Wearers Only:

• Removal of contact lenses for the required period of time prior to the screening refraction:

Contact Lens Type Minimum Discontinuation Time Soft 1 Week Soft Extended Wear 2 Weeks Soft Toric 3 Weeks Rigid gas permeable 2 Weeks per decade of wear

• Signed written informed consent
• Willingness and ability to comply with schedule for follow-up visits

Exclusion Criteria

• active infections, collagen vascular disease, allergic to product

All subjects meeting any of the following criteria will be excluded from this study:

• Eyes classified as either normal or atypical normal on the severity grading scheme.
• Corneal pachymetry at the screening exam that is \<300 microns at the thinnest point 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 or active corneal disease (e.g., herpes simplex, herpes zoster keratitis, recurrent erosion syndrome, acanthomeoeba, etc.)
• Clinically significant corneal scarring in the CXL treatment zone that is not related to keratoconus or, in the investigator's opinion, will interfere with the cross-linking procedure.
• Pregnancy (including plan to become pregnant) or lactation during the course of the study
• A known sensitivity to study medications
• Patients with cognitive or ambulatory conditions that would prevent eye drop compliance with 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 physician's opinion, would interfere with or prolong epithelial healing.