Corneal Ectasia, Keratoconus
Conditions
Keywords
keratoconus, collagen crosslinking, crosslinking, ectasia
Brief summary
The primary objective of this study is to determine the effectiveness and safety of corneal collagen cross-linking at irradiance levels of 9 and 18 mW/cm2.
Interventions
Application of ultraviolet light on the eye to be treated at an irradiance of 9 mW/cm2 for 10 minutes
Instillation of 0.1% riboflavin ophthalmic solution, one drop every 3 minutes for 30 minutes before the procedure and one drop every 3 minutes during the procedure.
Application of ultraviolet light on the eye to be treated at an irradiance of 18 mW/cm2 for 5 minutes.
Sponsors
Study design
Eligibility
Inclusion criteria
General Inclusion Criteria Prospective subjects must meet all of the following criteria to be eligible for participation: * 18 years of age or older * Signed written informed consent * Willingness and ability to comply with schedule for follow-up visits * Contact lens removal prior to evaluation and treatment Inclusion criteria for progressive keratoconus Prospective subjects must meet two of the following criteria: * Having a diagnosis of progressive keratoconus: * An increase of ≥ 1.00 D in the steepest keratometry value * An increase of ≥ 1.00 D in astigmatism manifest refraction * A myopic shift (decrease in the spherical equivalent) of ≥ 0.50 D on subjective manifest refraction * Presence of central or inferior steepening on the Pentacam map. * Axial topography consistent with keratoconus * Steepest keratometry (Kmax) value ≥ 47.00 D Inclusion criteria for ectasia Prospective subjects must meet the following criteria: * History of having undergone a keratorefractive procedure * Meeting two of the following criteria * Steepening by topography, either Pentacam or Humphrey * Thinning of cornea * Shift in the position of thinnest portion of cornea * Change in refraction with increasing myopia * Development of myopic astigmatism * Development of irregular astigmatism * Loss of best spectacle corrected acuity. 6.2
Exclusion criteria
Subjects meeting any of the following criteria will be excluded from this protocol: * Eyes classified as either normal, atypical normal, * Corneal pachymetry ≤ 350 microns at the thinnest point measured by Pentacam in the eye to be treated * A history of chemical injury or delayed epithelial healing in the eye 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 treatment * Inability to cooperate with diagnostic tests. * Patients with a current condition that, in the investigator's opinion, would interfere with or prolong epithelial healing. * Taking Vitamin C (ascorbic acid) supplements within 1 week of the cross-linking treatment. * Patients who are unable to remain supine and tolerate a lid speculum for an extended period of time.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Decrease in maximum corneal curvature | 3 and 6 months post-procedure |
Countries
United States