Keratoconus | Treatment of Keratoconus Using Collagen Cross-Linking
Keratoconus research study
What is the primary objective of this study?
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. .
Who is eligible to participate?
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
Which medical condition, disease, disorder, syndrome, illness, or injury is researched?
Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.
Drug:Riboflavin-5-phosphateRiboflavin 0.1% (10 mg riboflavin-5-phosphate in 10 ml dextran T-500 20% solution, supplied in a sterile, single dose container) will be applied to the cornea every 2-3 minutes for 15 minutes prior to starting UV irradiation. The UV irradiation will be given in six 5 minute intervals. Additional riboflavin will be administered following each 5 minute UV treatment.
Drug:Sham cross-linkingTopical anesthesia (lidocaine jelly 2%) will be used. Differing from the treatment group, no epithelium will be debrided, but instead, this step will be skipped and 2% methylcellulose solution with 1% sodium fluorescein will be applied to the cornea every 5 minutes for 15 minutes, and then every 5 minutes during the sham UV treatment. The patient will be placed under the UV device, and the aiming beam applied.
Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.
Cross-linking treatmentTopical anesthesia (lidocaine jelly 2%) will be used. The central 9 mm of corneal epithelium will be removed cautiously with an Amoils brush. Riboflavin 0.1% solution will be applied (10 mg riboflavin-5-phosphate in 10 ml dextran T-500 20% solution, supplied in a sterile, single dose container) to the cornea every 2-3 minutes for 15 minutes and then every 5 minutes thereafter. The UV source will be from the CBM VEGA X-linker (CSO, Florence, Italy). A wavelength of 370 nm will be used to direct 5.4 J/cm2 to the area of cornea debrided for 30 minutes. The distance from the UV source to the cornea will be 1.5 to 5.4 cm.
Sham treatment groupTopical anesthesia (lidocaine jelly 2%) will be used. Differing from the treatment group, no epithelium will be debrided, but instead, this step will be skipped and a 2% methylcellulose solution combined with 1% fluorescein dye will be applied to the cornea every 5 minutes for 30 minutes. The patient will be placed under the UV device, but instead of the UV light, the LED aiming beam will be applied for 30 minutes.
Start Date: September 2008
Completed Date: December 2011
Phase: Phase 2/Phase 3
Primary Outcome: Best corrected visual acuity
Secondary Outcome: Corneal resistance factor.
Study sponsors, principal investigator, and references
Principal Investigator: James J Reidy, M.D.
Lead Sponsor: University at Buffalo
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