Intacs intracorneal ring insertion for the treatment of keratoconus in Keratoconus - Clinical Trials Registry

Study Overview

Status

Unknown

Conditions

Keratoconus

Intervention / Treatment

Device: Intacs intracorneal ring insertion for the treatment of keratoconus

Detailed Description

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

Study Type

Interventional

Enrollment

20

Phase

Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Singapore
- - Singapore, Singapore, 168751
    - Recruiting
    - Singapore National Eye Centre
    - Sub-Investigator:
      
      Li - Lim, FRCS(Ed)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

21 years and older (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Primary Purpose: TREATMENT
Allocation: NON_RANDOMIZED
Interventional Model: SINGLE_GROUP
Masking: NONE

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Visual acuity
Corneal topography
Refraction

Secondary Outcome Measures

Outcome Measure
Patient satisfaction following procedure

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Singapore National Eye Centre

Investigators

Principal Investigator: Donald TH Tan, FRCS, Singapore National Eye Centre

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

October 1, 2005

Study Registration Dates

First Submitted

June 30, 2006

First Submitted That Met QC Criteria