The Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study
NCT ID: NCT00000155
Last Updated: 2005-06-24
Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
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UNKNOWN
OBSERVATIONAL
1995-06-30
Brief Summary
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To identify risk factors and protective factors that influence the severity and progression of keratoconus.
Detailed Description
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Previous large-scale studies of keratoconus have focused on incidence and prevalence, etiologies, or the clinical management of keratoconus. Few have characterized the course of the disease and risk factors for its progression in large samples of keratoconus patients. The incidence of vision-threatening corneal scarring in keratoconus is unknown. Patient's most frequent questions--how rapidly their keratoconus will progress, how bad their vision will become, whether they will need corneal surgery, how successful their contact lenses will be--cannot be answered on the basis of the current body of knowledge.
The need for a prospective, observational study of keratoconus patients is great. Results from this study will address keratoconus patient's unanswered questions and will enable eye care practitioners to manage this complex ocular disease better.
The Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study is a multicenter, observational study of 1,209 keratoconus patients followed for 3 years.
Patients are examined annually. Study measures include visual acuity, patient-reported quality of life, manifest refraction, keratometry, photodocumentation of the cornea to identify central corneal scarring, photodocumentation of the flattest contact lens that just clears the cornea, slit lamp biomicroscopy, and corneal topography. In rigid contact lens wearers, the fluorescein pattern of the patient's habitual contact lenses is photodocumented.
Patients are examined at 15 clinical centers. The clinical centers enrolled 1,209 patients in 12 months.
Conditions
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Study Design
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PROSPECTIVE
Eligibility Criteria
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Inclusion Criteria
Exclusion Criteria
12 Years
ALL
No
Sponsors
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National Eye Institute (NEI)
NIH
Locations
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University of California, Berkeley, School of Optometry
Berkeley, California, United States
Southern California College of Optometry
Fullerton, California, United States
Jules Stein Eye Institute, University of California at Los Angeles
Los Angeles, California, United States
Nova Southeastern University, Health Professions Division, College of Optometry
Fort Lauderdale, Florida, United States
University of Illinois at Chicago, Department of Ophthalmology and Visual Sciences
Chicago, Illinois, United States
Indiana University, School of Optometry
Bloomington, Indiana, United States
University of Missouri-St. Louis, School of Optometry
St Louis, Missouri, United States
SUNY State College of Optometry
New York, New York, United States
University Hospitals of Cleveland, Department of Ophthalmology
Cleveland, Ohio, United States
The Ohio State University, College of Optometry
Columbus, Ohio, United States
Pennsylvania College of Optometry, The Eye Institute
Philadelphia, Pennsylvania, United States
Northeastern Eye Institute
Scranton, Pennsylvania, United States
University of Utah, John Moran Eye Center
Salt Lake City, Utah, United States
Gundersen Lutheran
La Crosse, Wisconsin, United States
Countries
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References
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Barr JT, Gordon MO, Zadnik K, Pellican K, Edrington TB. Photodocumentation of corneal scarring. Collaborative Longitudinal Evaluation of Keratoconus Study Group. J Refract Surg. 1996 May-Jun;12(4):492-500. doi: 10.3928/1081-597X-19960501-13.
Edrington TB, Barr JT, Zadnik K, Davis LJ, Gundel RE, Libassi DP, McMahon TT, Gordon MO. Standardized rigid contact lens fitting protocol for keratoconus. Optom Vis Sci. 1996 Jun;73(6):369-75. doi: 10.1097/00006324-199606000-00003.
Gundel RE, Libassi DP, Zadnik K, Barr JT, Davis L, McMahon TT, Edrington TB, Gordon MO. Feasibility of fitting contact lenses with apical clearance in keratoconus. Optom Vis Sci. 1996 Dec;73(12):729-32. doi: 10.1097/00006324-199612000-00002.
Zadnik K, Barr JT, Gordon MO, Edrington TB. Biomicroscopic signs and disease severity in keratoconus. Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study Group. Cornea. 1996 Mar;15(2):139-46. doi: 10.1097/00003226-199603000-00006.
Other Identifiers
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NEI-57
Identifier Type: -
Identifier Source: org_study_id