Clinical trial NCT00841386: Treatment of Keratoconus Using Collagen Cross-Linking
Official title: Treatment of Keratoconus Using Collagen Cross-Linking By Means of Topical Riboflavin and UV Light.
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: PHASE2
PHASE3
Conditions: Keratoconus
Keywords: Cornea
Keratoconus
Ectasia
Riboflavin
Collagen cross-linking
Lead sponsor: University at Buffalo
Sponsor class: OTHER
First posted: 2009-02-11
Enrollment: 150
Sex: ALL
Minimum age (years): 16
Maximum age (years): 35
Standard ages: CHILD
ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The purpose of this study is to determine the effectiveness of collagen cross-linking in the cornea in halting the progression and possibly partially reversing the effects of keratoconus. Keratoconus is a progressive weakening in the cornea that causes irregular astigmatism and thinning of the cornea. The overall effect is reduction of vision, and in more advanced cases, scarring of the cornea that may lead to the need for corneal transplantation. Cross-linking has been shown increase the rigidity of the cornea. The patients would be treated once and then followed over 24 months. .

Detailed description: The goal is for two groups of approximately 66 patients to be included in the study. One eye from the first group will undergo treatment, while the second group of age matched individuals will serve as a control. It will be a prospective, randomized, blinded study. Each patient will be randomized at the beginning of enrollment in the study and will receive a randomization number. The following parameters will be followed: 1. Best corrected spectacle acuity (BCSA) 2. The steepest keratometry measurement (KMax) as measured by computerized corneal topography 3. Apical corneal thickness 4. Corneal mechanical resistance. These measurements will be repeated at 1 month, 3 months, 6 months, 12, 18, and 24 months following treatment.

Eligibility criteria: Inclusion Criteria:

* no prior history of ocular surgery
* treatment eye must have a maximum corneal power of between 47 D and 60 diopters
* corneal thickness must be greater than 400 µ
* absence of corneal scarring
* patients must meet the diagnostic criteria for keratoconus, which include one or more of the following features:

  * high myopia
  * corneal ectasia as viewed by slit-lamp exam or measured by pachometry
  * Vogt's striae
  * topographic findings of superior flattening and inferior steepening of the cornea
  * presence of Fleischer ring

Exclusion Criteria:

* history of prior ocular surgery (history of contact lens use is not an exclusion criterion)
* average corneal power \> 60 D
* presence of corneal scarring
* corneal thickness 400 µ or less
* history of herpes simplex virus keratitis
* history of uveitis
* pre-existing glaucoma

Primary outcomes:
measure: Best corrected visual acuity
timeFrame: 24 months
measure: Spherical equivalent power of the cornea (Best spectacle refraction)
timeFrame: 24 months
measure: KMax: the maximum corneal curvature
timeFrame: 24 months
measure: Average corneal power of the cornea in the central 4 mm.
timeFrame: 24 months
Secondary outcomes:
measure: Corneal resistance factor.
timeFrame: 24 months
measure: Maximal posterior surface elevation of the cornea.
timeFrame: 24 months
measure: Apical corneal thickness.
timeFrame: 24 months
measure: Endothelial count.
timeFrame: 24 months
Other outcomes:
Locations:
city: Amherst
country: United States
facility: Fichte,Endl, & Elmer EyeCare
state: New York
city: Buffalo
country: United States
facility: The Ira G. Ross Eye Institute
state: New York
Study officials:
affiliation: SUNY at Buffalo School of Medicine & Biomedical Sciences
name: James J Reidy, M.D.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Natarajan R, Padmanabhan P, Guruswami S. Hydration behavior of porcine cornea crosslinked with riboflavin and ultraviolet A. J Cataract Refract Surg. 2007 Sep;33(9):1503. doi: 10.1016/j.jcrs.2007.04.047. No abstract available.
citation: Mazzotta C, Balestrazzi A, Traversi C, Baiocchi S, Caporossi T, Tommasi C, Caporossi A. Treatment of progressive keratoconus by riboflavin-UVA-induced cross-linking of corneal collagen: ultrastructural analysis by Heidelberg Retinal Tomograph II in vivo confocal microscopy in humans. Cornea. 2007 May;26(4):390-7. doi: 10.1097/ICO.0b013e318030df5a.
citation: Spoerl E, Mrochen M, Sliney D, Trokel S, Seiler T. Safety of UVA-riboflavin cross-linking of the cornea. Cornea. 2007 May;26(4):385-9. doi: 10.1097/ICO.0b013e3180334f78.
citation: Mazzotta C, Traversi C, Baiocchi S, Sergio P, Caporossi T, Caporossi A. Conservative treatment of keratoconus by riboflavin-uva-induced cross-linking of corneal collagen: qualitative investigation. Eur J Ophthalmol. 2006 Jul-Aug;16(4):530-5. doi: 10.1177/112067210601600405.
citation: Wollensak G. Crosslinking treatment of progressive keratoconus: new hope. Curr Opin Ophthalmol. 2006 Aug;17(4):356-60. doi: 10.1097/01.icu.0000233954.86723.25.
citation: Caporossi A, Baiocchi S, Mazzotta C, Traversi C, Caporossi T. Parasurgical therapy for keratoconus by riboflavin-ultraviolet type A rays induced cross-linking of corneal collagen: preliminary refractive results in an Italian study. J Cataract Refract Surg. 2006 May;32(5):837-45. doi: 10.1016/j.jcrs.2006.01.091.
citation: Kohlhaas M, Spoerl E, Schilde T, Unger G, Wittig C, Pillunat LE. Biomechanical evidence of the distribution of cross-links in corneas treated with riboflavin and ultraviolet A light. J Cataract Refract Surg. 2006 Feb;32(2):279-83. doi: 10.1016/j.jcrs.2005.12.092.
citation: Wollensak G, Spoerl E, Seiler T. Riboflavin/ultraviolet-a-induced collagen crosslinking for the treatment of keratoconus. Am J Ophthalmol. 2003 May;135(5):620-7. doi: 10.1016/s0002-9394(02)02220-1.
citation: Mencucci R, Mazzotta C, Rossi F, Ponchietti C, Pini R, Baiocchi S, Caporossi A, Menchini U. Riboflavin and ultraviolet A collagen crosslinking: in vivo thermographic analysis of the corneal surface. J Cataract Refract Surg. 2007 Jun;33(6):1005-8. doi: 10.1016/j.jcrs.2007.03.021.