Screening Aid to Identify Corneas That May Have Pathologies or Other Conditions

NCT ID: NCT00396188

Last Updated: 2015-08-17

Study Results

Results pending

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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Recruitment Status

COMPLETED

Total Enrollment

769 participants

Study Classification

OBSERVATIONAL

Study Start Date

2007-02-28

Study Completion Date

2008-02-29

Brief Summary

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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

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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).

Conditions

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Corneal Diseases

Study Design

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Observational Model Type

CASE_CONTROL

Study Time Perspective

CROSS_SECTIONAL

Study Groups

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Normals

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

No interventions assigned to this group

Keratoconus

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

No interventions assigned to this group

Myopic Laser Vision Correction

Patients who have undergone myopic:

1. LASIK
2. PRK
3. LASEK

No interventions assigned to this group

Hyperopic Laser Vision Correction

Patients who have undergone hyperopic:

1. LASIK
2. PRK
3. LASEK

No interventions assigned to this group

Orthokeratology

1\. Patients using specially designed rigid contact lenses to reshape the cornea to temporarily reduce or eliminate refractive error.

No interventions assigned to this group

Others

1\. Corneal conditions (diseases/ pathologies/surgeries) that can potentially affect the corneal surface that are not listed above (e.g. pellucid marginal degeneration; postoperative corneal transplant, intra-corneal ring segments, refractive keratotomy, conductive keratoplasty; peripheral ulcerative keratitis, Terrien's marginal degeneration; etc.).

No interventions assigned to this group

Eligibility Criteria

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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.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Carl Zeiss Meditec, Inc.

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Jon Dishler, M. D.

Role: PRINCIPAL_INVESTIGATOR

Dishler Laser Institute

David J Schanzlin, M. D.

Role: PRINCIPAL_INVESTIGATOR

Shiley Eye Center-University of California San Diego

Dennis Burger, O. D.

Role: PRINCIPAL_INVESTIGATOR

Kaiser Permanente, Oakland

Patrick Caroline, COT

Role: PRINCIPAL_INVESTIGATOR

Pacific University

Tyson Brunstetter, O. D.

Role: PRINCIPAL_INVESTIGATOR

Naval Training Center-Refractive Surgery Clinic

Kevin Reeder, O.D.

Role: PRINCIPAL_INVESTIGATOR

Carmel Mountain Vision Care Center

Locations

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Shiley Eye Center-University of California San Diego

La Jolla, California, United States

Site Status

Carmel Mountain Vision Care Center

San Diego, California, United States

Site Status

Dishler Laser Institute

Greenwood Village, Colorado, United States

Site Status

Pacific University

Forest Grove, Oregon, United States

Site Status

Countries

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United States

References

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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.

Reference Type BACKGROUND
PMID: 9856763 (View on PubMed)

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.

Reference Type BACKGROUND
PMID: 16357645 (View on PubMed)

Other Identifiers

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Atlas II-2006-1-v1

Identifier Type: -

Identifier Source: org_study_id

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