Study of the Safety and Effectiveness of Photochemically Induced Collagen Cross- Linking at Higher Irradiances in Patients With Keratoconus or Ectasia
Overview
- Phase
- Not Applicable
- Intervention
- UVA Light with irradiance exposure of 9 mW/cm2
- Conditions
- Keratoconus
- Sponsor
- Stephen Trokel
- Locations
- 1
- Primary Endpoint
- Change in Total Optical Aberrations of the Cornea following Cross-Linking
- Status
- Withdrawn
- Last Updated
- 3 years ago
Overview
Brief Summary
The purpose of the study is to see if brighter lights will allow for shortening of the treatment time required to stabilize the eyes of patients with keratoconus or a bulging cornea. The investigators will be comparing the therapeutic effects of two different higher brightnesses of ultra violet light on a riboflavin treated eye. One light will be twice as bright as the other and the exposure time of these brighter lights to deliver equivalent energy to the cornea will be reduced from the standard 30 minutes to 10 and 5 minutes. Riboflavin is vitamin B2 and the investigators are trying to determine if an identical clinical effect can be achieved the brighter treatment lights are used for shorter times. The investigators will also monitor the clinical effect and the status of the cornea to see if additional risks are associated with the brighter light.
Investigators
Stephen Trokel
Professor of Clinical Ophthalmology
Columbia University
Eligibility Criteria
Inclusion Criteria
- •Subjects who have one or both eyes that meet two of the following criteria will be considered candidates for this study:
- •16 years of age or older
- •Having a diagnosis of progressive keratoconus or pellucid marginal degeneration.
- •Characteristic pattern of deformity as analyzed by the Pentacam map.
- •Minimal thickness of 350 microns
- •The ability to sign a written informed consent
- •States a willingness and ability to comply with schedule for follow-up visits
- •Subject willing to remove contact lenses prior to evaluation and treatment
- •Inclusion criteria for ectasia
- •History of having undergone a keratorefractive procedure and show:
Exclusion Criteria
- •Subjects meeting any of the following criteria will be excluded from this study:
- •Subjects meeting any of the following criteria will be excluded from this protocol:
- •Eyes classified as either normal or atypical normal,
- •Corneal pachymetry ≤ 350 microns at the thinnest point in treatment zone measured by Pentacam.
- •A history of delayed epithelial healing.
- •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 is severe enough to prevent 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.
Arms & Interventions
9 mw/cm2 at 10 minutes group
30 patients will be treated with UVA light source at 9 mw/cm2 at 10 minutes. Drug: Riboflavin Dose:1 drop every 2 to 3 minutes for 15 to 20 minutes
Intervention: UVA Light with irradiance exposure of 9 mW/cm2
9 mw/cm2 at 10 minutes group
30 patients will be treated with UVA light source at 9 mw/cm2 at 10 minutes. Drug: Riboflavin Dose:1 drop every 2 to 3 minutes for 15 to 20 minutes
Intervention: Riboflavin 0.1% ophthalmic solution
Outcomes
Primary Outcomes
Change in Total Optical Aberrations of the Cornea following Cross-Linking
Time Frame: Baseline to 6 months
Assessment of changes in corneal curvature, as analyzed using a Pentacam Scheimpflug Analyzer will be used in all patients. This allows measurement of corneal thickness, maximum and minimum curvatures and aberration analysis of the cornea as an optical element. The most significant objective measure of change is the total Higher Order Aberrations of the cornea and the Kmax, or steepest curvature of the cornea. Analysis of corneal curvature is directly related to improvement in the corneal shape which is directly related to visual function.