Clinical trial NCT00396188: Screening Aid to Identify Corneas That May Have Pathologies or Other Conditions
Official title: Corneal Analysis - Pathology Detection Aid
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Corneal Diseases
Keywords: Keratoconus
LASIK
Orthokeratology
Pellucid Marginal Degeneration
Refractive Surgery
normal cornea
post myopic LASIK
post hyperopic LASIK
corneal pathologies (e.g. pellucid marginal degeneration)
Lead sponsor: Carl Zeiss Meditec, Inc.
Sponsor class: INDUSTRY
First posted: 2006-11-06
Enrollment: 769
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Subjects will consist of patients seeking consult in the Principal Investigator's (PI) clinical practice and volunteers responding to the study's advertisements.

Brief summary: The purpose of this study is to determine the ability of a proprietary software screening tool to discriminate normal corneas (front surface of the eye) from previously diagnosed corneal conditions (diseases/surgeries/pathologies) and to determine the repeatabiltity and reproducibility of the Atlas II corneal topographer in normal human corneas.

Detailed description: 1. To establish reference values for SF, CIM, and TKM in subjects with normal corneas.
2. To establish reference values for SF, CIM, and TKM in subjects who underwent myopic laser vision correction.
3. To establish reference values for SF, CIM, and TKM in subjects who underwent hyperopic laser vision correction.
4. To establish reference values for SF, CIM, and TKM in subjects who were diagnosed to have keratoconus.
5. To establish reference values for SF, CIM, and TKM in subjects with history of orthokeratology.
6. To establish reference values for SF, CIM, and TKM in subjects with previously diagnosed corneal conditions (diseases/pathologies/surgeries) affecting the corneal surface that are not listed above.
7. To determine the repeatabiltity and reproducibility of the Atlas II corneal topographer in normal human corneas using true elevation data and axial curvature.
8. To determine the sensitivity, specificity, and accuracy of the Pathfinder II Corneal Analysis software in discriminating normal corneas from previously diagnosed corneal conditions (diseases/pathologies/surgeries) affecting the corneal surface (Phase II).

Eligibility criteria: Inclusion Criteria:

Normals

* Patients seeking initial laser vision correction that were screened to be good candidates for the procedure.
* No history of refractive or other ocular surgery.
* No corneal pathologies.
* Normal corneal topography.
* Contact lens wearers should discontinue use at least 2 weeks for hard contacts, and 3 days for soft lenses prior to imaging.

Keratoconus

* An irregular cornea determined by distorted keratometry mires, distortion of the retinoscopic, or ophthalmoscopic red reflex (or a combination of these)
* At least one of the following biomicroscopic signs: Vogt's striae, Fleischer's ring of \>2 mm arc, or corneal scarring consistent with keratoconus.
* Contact lens wearers should discontinue use preferably 1 day or at least half an hour prior to imaging.

Myopic Laser Vision Correction

Patients who have undergone myopic:

* LASIK
* PRK
* LASEK

Hyperopic Laser Vision Correction

Patients who have undergone hyperopic:

* LASIK
* PRK
* LASEK

Orthokeratology

* Patients using specially designed rigid contact lenses to reshape the cornea to temporarily reduce or eliminate refractive error.
* Subjects must be 18 years of age or older; able and willing to make the required visit; and able and willing to give consent.

Exclusion Criteria:

* Patients that underwent corneal transplantation or any ocular surgery for the following categories: normal, keratoconus, and orthokeratology)
* Any active infection or inflammation of the cornea.
* PI decides that subject is not suitable due to medical risk.

Primary outcomes:
measure: Reference values of normal and previously diagnosed corneal conditions by Atlas II corneal topographer
timeFrame: 1-2 hours
Secondary outcomes:
measure: Repeatabiltity and reproducibility of the Atlas II corneal topographer in human corneas
timeFrame: 1-2 hours
Other outcomes:
Locations:
city: La Jolla
country: United States
facility: Shiley Eye Center-University of California San Diego
state: California
city: San Diego
country: United States
facility: Carmel Mountain Vision Care Center
state: California
city: Greenwood Village
country: United States
facility: Dishler Laser Institute
state: Colorado
city: Forest Grove
country: United States
facility: Pacific University
state: Oregon
Study officials:
affiliation: Dishler Laser Institute
name: Jon Dishler, M. D.
role: PRINCIPAL_INVESTIGATOR
affiliation: Shiley Eye Center-University of California San Diego
name: David J Schanzlin, M. D.
role: PRINCIPAL_INVESTIGATOR
affiliation: Kaiser Permanente, Oakland
name: Dennis Burger, O. D.
role: PRINCIPAL_INVESTIGATOR
affiliation: Pacific University
name: Patrick Caroline, COT
role: PRINCIPAL_INVESTIGATOR
affiliation: Naval Training Center-Refractive Surgery Clinic
name: Tyson Brunstetter, O. D.
role: PRINCIPAL_INVESTIGATOR
affiliation: Carmel Mountain Vision Care Center
name: Kevin Reeder, O.D.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Zadnik K, Barr JT, Edrington TB, Everett DF, Jameson M, McMahon TT, Shin JA, Sterling JL, Wagner H, Gordon MO. Baseline findings in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study. Invest Ophthalmol Vis Sci. 1998 Dec;39(13):2537-46.
citation: Twa MD, Parthasarathy S, Roberts C, Mahmoud AM, Raasch TW, Bullimore MA. Automated decision tree classification of corneal shape. Optom Vis Sci. 2005 Dec;82(12):1038-46. doi: 10.1097/01.opx.0000192350.01045.6f.