Intacs for Keratoconus

NCT ID: NCT00347230

Last Updated: 2006-07-07

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

UNKNOWN

Clinical Phase

NA

Total Enrollment

20 participants

Study Classification

INTERVENTIONAL

Study Start Date

2005-10-31

Brief Summary

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To study the effects Intacs intracorneal ring segments(Addition Technology, Inc) insertion in the treatment of keratoconus

Detailed Description

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The purpose of this evaluation is to study the effects of implanting INTACS inserts, identical to those commercially available to correct myopia, into the corneal stroma of patients with keratoconus (mild to moderate) and having a clear cornea. The principle of the procedure is to flatten the cornea deformed by keratoconus. One or two segments of the same or a different thickness will be selected to reduce the asymmetric astigmatism responsible for the patient impaired visual acuity.

The surgical technique is based on locating the INTACS inserts on the flattest axis of the refractive error, making the incision on the steepest axis, using 150 degree arc length inserts with different sizes (0.250, 0.300, 0.350, 0.400 \& 0.450 mm) according to a nomogram designed for this technique using the INTACS Instrumentation (10-Step Prolate System instruments).

The corneal lamellar channel creation may be performed using the INTACS instrumentation or using the Femtosecond laser (Femtec 20/10 laser\[Femtec,Heidelberg Germany\])

Primary Assessment Criteria

* Evaluation of the safety of the device for the treatment of patients with keratoconus (mild to moderate)
* Maintenance of best corrected visual acuity (BCVA)
* Improvement in uncorrected visual acuity (UCVA)
* Reduction in manifest refraction spherical equivalent
* Reduction in asymmetric astigmatism

Secondary Assessment Criteria

* Evaluation of the effect of INTACS inserts placement for treatment of corneal ectasia
* Determination of patient satisfaction following the INTACS inserts procedure Patients meeting the eligibility criteria are required to sign a Patient Informed Consent Form prior to study participation.

A thorough examination is perform to evaluate the following:

* Manifest refraction results - Uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA)
* Cycloplegic refraction results - Uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA)
* Corneal topography
* Pachymetry
* Step axis location
* Location of incision placement
* Subjective feedback about quality of vision (Excellent, Good, Fair and Poor)

Post-operative Assessment(at 1 day, 1 week, 1 month and 3 months postop)

* Uncorrected visual acuity (UCVA) and best corrected visual acuity with manifest refraction(BCVA) at designated time interval
* Cycloplegic refraction results - Uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) at designated time interval
* Corneal topography at designated time interval
* Pachymetry at designated time interval
* Subjective visual outcome ratings over time (Excellent, Good, Fair and Poor)
* Report adverse events

Conditions

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Keratoconus

Keywords

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Intacs ring segments Keratoconus

Study Design

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Allocation Method

NON_RANDOMIZED

Intervention Model

SINGLE_GROUP

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Interventions

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Intacs intracorneal ring insertion for the treatment of keratoconus

Intervention Type DEVICE

Eligibility Criteria

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Inclusion Criteria

* Patients must have keratoconus (mild to moderate).
* Visual acuity with contact lenses must be better than or equal to (20/40).
* Patients must be intolerant of contact lenses, i.e., they must be unable to wear contact lenses for a whole day.
* Patients will have a corneal thickness of 425 microns at the site of ICRS (INTACS inserts) placement (the thinnest region of the cornea).
* In terms of general health, patients must not have any illnesses posing an immediate threat to life.
* Patients must have provided written informed consent at least one week prior to surgery.
* Patients must over 21 years of age.
* Patients' contact lenses must have been removed at least one week prior to surgery for soft lenses and two weeks prior to surgery for hard lenses.

Exclusion Criteria

* Positive pregnancy test.
* Breast-feeding.
* History of previous ophthalmologic surgery on the operative eye.
* Patients with corneal stromal disorders.
* Patients with history of herpetic keratitis.
* Patients with retinal disorders.
* Corneal grafts.
* Patients refusing to remove contact lenses one week before surgery for soft lenses and two weeks before surgery for hard lenses.
* Patients with amblyopia (VA \<1110 for the contralateral eye).
* Patients with corneal thickness \<425 microns.
* Patients with TOP \<10 mmHg or \>21 mmHg.
* Patients taking part in other biomedical research in the 30 days prior to the start of this study.
* Patients with an uncooperative disposition.
Minimum Eligible Age

21 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Singapore National Eye Centre

OTHER_GOV

Sponsor Role lead

Principal Investigators

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Donald TH Tan, FRCS

Role: PRINCIPAL_INVESTIGATOR

Singapore National Eye Centre

Locations

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Singapore National Eye Centre

Singapore, , Singapore

Site Status RECRUITING

Countries

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Singapore

Central Contacts

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Li - Lim, FRCS(Ed)

Role: CONTACT

Phone: 65-63228896

Email: [email protected]

Donald TH Tan, FRCS

Role: CONTACT

Phone: 65-63224500

Email: [email protected]

References

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Colin J, Cochener B, Savary G, Malet F, Holmes-Higgin D. INTACS inserts for treating keratoconus: one-year results. Ophthalmology. 2001 Aug;108(8):1409-14. doi: 10.1016/s0161-6420(01)00646-7.

Reference Type BACKGROUND
PMID: 11470691 (View on PubMed)

Colin J, Cochener B, Savary G, Malet F. Correcting keratoconus with intracorneal rings. J Cataract Refract Surg. 2000 Aug;26(8):1117-22. doi: 10.1016/s0886-3350(00)00451-x.

Reference Type BACKGROUND
PMID: 11008037 (View on PubMed)

Siganos D, Ferrara P, Chatzinikolas K, Bessis N, Papastergiou G. Ferrara intrastromal corneal rings for the correction of keratoconus. J Cataract Refract Surg. 2002 Nov;28(11):1947-51. doi: 10.1016/s0886-3350(02)01495-5.

Reference Type BACKGROUND
PMID: 12457667 (View on PubMed)

Schanzlin DJ, Asbell PA, Burris TE, Durrie DS. The intrastromal corneal ring segments. Phase II results for the correction of myopia. Ophthalmology. 1997 Jul;104(7):1067-78. doi: 10.1016/s0161-6420(97)30183-3.

Reference Type BACKGROUND
PMID: 9224455 (View on PubMed)

Siganos CS, Kymionis GD, Kartakis N, Theodorakis MA, Astyrakakis N, Pallikaris IG. Management of keratoconus with Intacs. Am J Ophthalmol. 2003 Jan;135(1):64-70. doi: 10.1016/s0002-9394(02)01824-x.

Reference Type BACKGROUND
PMID: 12504699 (View on PubMed)

Other Identifiers

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R419/14/2005

Identifier Type: -

Identifier Source: org_study_id