Management of Patients With Keratoconus With Intacs

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00384501
Recruitment Status : Terminated
First Posted : October 6, 2006
Last Update Posted : October 6, 2006
Information provided by:
University Hospital of Crete

Brief Summary:

Purpose To evaluate long-term follow up of Intacs microthin prescription inserts (Addition Technology Inc, Fremont, Calif) for the management of keratoconus.

Design A long-term (five years) retrospective, follow-up study

Condition or disease Intervention/treatment Phase
Keratoconus Device: Intacs Not Applicable

Detailed Description:

Subjects and Methods

Ethical committee approval was obtained for the original trial, and patients were asked to sign an informed consent form (in accordance with Institutional guidelines and to the Declaration of Helsinki) before treatment and for further follow-up examinations. The registration information for this clinical trial is available to the public through the National Institute of Health database.

The surgical procedure was done under topical anesthesia. Two Intacs segments of 0.45-mm thickness were inserted so as to embrace the steepest keratoconus meridian, according to the topographic image, aiming at maximal flattening.

The corneal thickness was measured intraoperatively at the incision site and peripherally in the cornea along the ring placement markings with ultrasonic pachymetry (Sonogage, Cleveland, Ohio, USA). Using a diamond knife, set at 70% of the thinnest corneal measurement, a 0.9-mm radial incision was formed, and corneal pockets were created using two Sinskey hooks and a Suarez spreader. Two corneal tunnels were then formed using clockwise and counterclockwise dissectors under suction created by a vacuum-centering guide. The two polymethyl methacrylate (PMMA) segments (0.45-mm thickness) were implanted in the respective corneal tunnels, maintaining a space of approximately 2.0-mm between their ends and 1.5 mm between the opposite edge of each segment and the edge of the incision. The incision site was sutured using a single 10/0 nylon stitch.

Postoperative evaluation Postoperatively, all eyes received antibiotic/steroid combination eye drops 4 times per day for 2 weeks. In addition, all patients were instructed to use preservative-free artificial tears frequently. The sutures were removed 2 weeks after surgery.

Group differences for continuous variables were tested using the paired Student t tests. The change in manifest refraction (spherical equivalent) (MRSE) and topographic k values and topographic astigmatism were plotted over time to determine long-term stability, and the difference as a function of time was analyzed using paired 2-tailed t tests (at time intervals of preoperative to 1 month, 1 to 3 months, 3 to 6 months, 6 to 12 months, and every year of follow up period). Results are presented as means + standard deviation [SD]. A P value less than .05 was regarded as statistically significant.

Study Type : Interventional  (Clinical Trial)
Enrollment : 25 participants
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Intacs for the Treatment of Keratoconus
Study Start Date : January 2000
Study Completion Date : July 2006

Resource links provided by the National Library of Medicine

Primary Outcome Measures :
  1. refractive stability, UCVA, BSCVA, complications

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • All patients had clear central corneas and contact lens intolerance (rigid gas permeable contact lenses intolerance, frequent contact lens displacement, unsatisfactory visual acuity),

Exclusion Criteria:

  • history of herpes keratitis; diagnosed autoimmune disease; and systemic connective tissue disease.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00384501

Sponsors and Collaborators
University Hospital of Crete
Principal Investigator: George D Kymionis, M.D., Ph.D University of Crete

Publications of Results: Identifier: NCT00384501     History of Changes
Other Study ID Numbers: PEPAGNI-6175
First Posted: October 6, 2006    Key Record Dates
Last Update Posted: October 6, 2006
Last Verified: October 2006

Keywords provided by University Hospital of Crete:

Additional relevant MeSH terms:
Corneal Diseases
Eye Diseases