Management of Patients With Keratoconus With Intacs

Not Applicable

Terminated

• Conditions: Keratoconus

• Registration Number: NCT00384501
• Lead Sponsor: 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

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 Timeline

• Study Start: 2000-01
• Study Completion: 2006-07
• Status Verified: 2006-10
• Study First Submitted: 2006-10-05
• Study First Submitted QC: 2006-10-05
• Last Update Submitted: 2006-10-05
• Study First Posted: 2006-10-06
• Last Update Posted: 2006-10-06

Recruitment & Eligibility

• Status: TERMINATED
• Sex: All
• Target Recruitment: 25

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
refractive stability, UCVA, BSCVA, complications