Clinical trial NCT02095730: Corneal Cross-Linking Comparing Variables
Official title: Study of Safety and Efficacy of Photochemically Induced Collagen Cross-Linking at an Irradiance of 18 mW/cm2 as Constant or Pulsed Treatment in Eyes With Unstable Corneas Due to Keratoconus, Ectasia, or Post-Incisional Refractive Surgery
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: PHASE3
Conditions: Unstable Corneas
Keywords: crosslinking
cornea
keratoconus
ectasia
irradiance
riboflavin
Lead sponsor: Crowd Health Research, LTD
Sponsor class: OTHER
First posted: 2014-03-26
Enrollment: 500
Sex: ALL
Minimum age (years): 12
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The purpose of this study is to evaluate the Safety and Efficacy of Corneal Cross Linking in a Continuous Beam versus Pulsed Treatments across epithelium on and epithelium off surfaces.


Eligibility criteria: Inclusion Criteria Keratoconus:

* 12 years of age or older
* Having a clinical diagnosis of progressive keratoconus consistent with:

  1. An increase of ≥ 1.00 D in the steepest keratometry value
  2. An increase of ≥ 1.00 D in astigmatism manifest refraction
  3. A myopic shift (decrease in the spherical equivalent) of ≥ 0.50 D on subjective manifest refraction
* Presence of central or inferior steepening on the topography map.
* Axial topography consistent with keratoconus
* Steepest keratometry (Kmax) value ≥ 47.00 D
* 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 Post-Surgical Ectasia:

* History of having undergone a keratorefractive procedure and:

  1. Steepening by topography
  2. Thinning of cornea
  3. Shift in the position of thinnest portion of cornea
  4. Change in refraction with increasing myopia
  5. Development of myopic astigmatism
  6. Development of irregular astigmatism
  7. Loss of Best Spectacle Corrected Visual Acuity
* At least two of the above criteria must be present.

Inclusion Criteria Intacts:

* Should the patient have undergone prior Intacs or other intra-corneal ring segment surgery for keratoconus or post-surgical ectasia at least 6 months prior, and is also experiencing at least two of the above ectasia symptoms, they can be included in the study.

  1. These patients would have the choice of ring explant before Cross-Linking.
  2. Cross-Linking may still be performed if the patient wishes to retain the rings.
* Should a patient's situation due to factors such as significantly high myopia or astigmatism should warrant simultaneous placement of Intacs and cross-linking in the investigators opinion, then this option can be offered to the patient. Such interventions would be tracked as a different arm of the study.

Inclusion Criteria RK/AK Fluctuation:

* History of having undergone radial keratotomy (RK) and or astigmatic keratotomy (AK) surgery.
* Expressing complaints about difficulties due to vision changing during the same day.
* A difference in their Manifest Refraction (MRx) of greater than 0.75 D measured on the same day, at least 6 hours apart.
* Intacs surgery will not be considered in patients with RK/AK.

Exclusion Criteria:

* Eyes classified as either normal, atypical normal,
* Corneal pachymetry ≤ 350 microns at the thinnest point measured by Orbscan, Pentacam, or ultrasound in the eye to be treated
* A history of chemical injury or delayed epithelial healing in the eye to be treated.
* A known sensitivity to study medications
* Patients with significant 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 comfortable and stable, and tolerate a lid speculum for the appointed period of time for the procedure.

Primary outcomes:
measure: Visual Acuity
timeFrame: 2 years
Secondary outcomes:
Other outcomes:
Locations:
city: Santa Rosa
country: United States
facility: LaserVue Eye
state: California
city: Denver
country: United States
facility: Icon Lasik
state: Colorado
city: Jacksonville
country: United States
facility: Gulani Vision Institute
state: Florida
city: Atlanta
country: United States
facility: Eye Consultants of Atlanta
state: Georgia
city: Des Plaines
country: United States
facility: Midwest Center for Sight
state: Illinois
city: Pekin
country: United States
facility: Bond Eye Associates
state: Illinois
city: Leawood
country: United States
facility: Discover Vision Center
state: Kansas
city: Hattiesburg
country: United States
facility: Southern Eye Center
state: Mississippi
city: Springfield
country: United States
facility: Mercy Clinic Eye Specialists
state: Missouri
city: Las Vegas
country: United States
facility: LASIK of Nevada
state: Nevada
city: Elkins Park
country: United States
facility: James Lewis MD PC
state: Pennsylvania
city: Harrisburg
country: United States
facility: Memorial Eye Institute
state: Pennsylvania
city: Mt. Pleasant
country: United States
facility: Carolina Eye Care
state: South Carolina
city: Goodlettsville
country: United States
facility: Loden Vision Centers
state: Tennessee
city: San Antonio
country: United States
facility: Parkhurst NuVision
state: Texas
city: Vienna
country: United States
facility: Liberty Laser Eye Center
state: Virginia
Study officials:
affiliation: Liberty Laser Eye Center
name: Nancy A Tanchel, MD
role: PRINCIPAL_INVESTIGATOR
References: