Clinical Trials Logo

Clinical Trial Summary

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


Clinical Trial 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 Design

Allocation: Non-Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment


Related Conditions & MeSH terms


NCT number NCT00347230
Study type Interventional
Source Singapore National Eye Centre
Contact Li - Lim, FRCS(Ed)
Phone 65-63228896
Email Lim.Li@snec.com.sg
Status Recruiting
Phase N/A
Start date October 2005

See also
  Status Clinical Trial Phase
Recruiting NCT04570020 - Scleral Lens Fitting Using Wide-Field OCT
Recruiting NCT02921009 - McNeel Eye Center Corneal Crosslinking Study N/A
Terminated NCT02762253 - Study of the Safety and Effectiveness of Photochemically Induced Collagen Cross-Linking in Eyes With Keratoconus. Phase 2
Completed NCT01691651 - Botulinum Toxin A for the Treatment of Keratoconus N/A
Completed NCT01527708 - Accuracy of Curvature and Wavefront Aberrations of Posterior Corneal Surface, in Keratoconic and Post-CXL Corneas N/A
Completed NCT01527721 - Blurring Strength & Aberrometric Changes Following Corneal Cross-linking (CxL) and CxL Combined With Photorefractive Keratectomy (PRK) in Keratoconus N/A
Recruiting NCT00841386 - Treatment of Keratoconus Using Collagen Cross-Linking Phase 2/Phase 3
Completed NCT00347074 - A Clinical Study of Keratoconus in Asian Patients and Assessment of Different Topographic Patterns of Keratoconus in Asian Patients N/A
Completed NCT03187912 - Accelerated Corneal Cross-linking With Different Riboflavin Solutions Phase 3
Completed NCT00584285 - Corneal Topographer Fluorescein Patterns
Completed NCT03511495 - Reliability of Topography Measurements in Keratoconus
Not yet recruiting NCT05395650 - Cyanocobalamin as Photosensitizing Agent
Completed NCT04418999 - Safety and Efficacy of Intracanalicular Dexamethasone Compared to Loteprednol Etabonate in Patients With Keratoconus Early Phase 1
Completed NCT03235856 - Retrospective Digital Computer Analysis of Keratoconus Evolution - REDCAKE
Completed NCT05019768 - Topo-pachimetric Accelerated Epi-On Cross-linking Compared to Dresden Protocol Using Riboflavin With Vitamin E TPGS N/A
Withdrawn NCT01789333 - Higher Irradiance in Keratoconus Ectasia N/A
Completed NCT05114928 - Correlation Between Q-value Changes and Progression of Pediatric Keratoconus.
Completed NCT03647046 - Custom Anterior Surfacing of Scleral Lens for Vision Quality Improvement in Patients With Keratoconus N/A
Recruiting NCT04439552 - fMRI and IVCM Cornea Microscopy of CXL in Keratoconus
Recruiting NCT06100939 - Epithelium-On Corneal Cross-linking in Subjects 8 to 45 Years of Age With Keratoconus Phase 3