T-Cat Laser & Cross-linking for Keratoconus

NCT00777322 | Completed DMC

• 1 other identifier: REC Ref: 07/H0721/94
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to determine whether excimer laser corneal surface ablation (T-Cat) can be safely combined with simultaneous corneal collagen cross-linking treatment to produce an improved and stable corneal profile in the treatment of keratoconus.

Conditions

Keratoconus; Pellucid Marginal Degeneration

Keywords

keratoconus; pellucid marginal degeneration; corneal ectasia; collagen cross-linking; riboflavin; UV light; excimer laser; Topography-Computer Assisted Treatment (T-Cat); Wavelight Allegretto laser

Outcome Measures

Primary Outcomes (1)

• The difference in the pre- and post-operative unaided visual acuity, best corrected visual acuity, and refraction.

  At six months

Secondary Outcomes (1)

• Corneal topographic profile.

  At six months

Study Arms (1)

Interventional study

EXPERIMENTAL

Patients with known keratoconus or pellucid marginal degeneration will be invited to join the study. The study is partly a continuation in the management of patients who have had previous keratophakia, who will have near-normal or supra-physiological levels of corneal thickness. It is also intended for patients with relatively mild keratoconus who have sufficient corneal thickness to allow a limited laser ablation whilst still leaving a residual stromal bed of at least 350μ.

Procedure: Excimer laser ablation, and collagen cross-linking

Interventions

Excimer laser ablation, and collagen cross-linking PROCEDURE

Surgery is performed with topical anaesthesia. The central corneal epithelium is removed. Excimer laser ablation is applied (typically 15-30 seconds). Residual bed thickness is checked with an ultrasonic pachymeter. Topical application of riboflavin 0.1% in dextran is commenced at 5 minute intervals. When an adequate saturation of the anterior chamber with riboflavin has been achieved, cross-linking treatment will proceed. Output from the UV light generating equipment is measured with a UV light meter and set at 3mW/cm². Thirty minutes of treatment is given, interrupted at five minute intervals by the application of more topical riboflavin drops. Finally the eye has a bandage soft contact lens placed, with preservative free topical antibiotic, steroid, and cycloplegic drop application.

Also known as: Ricrolin (riboflavin 0.1% in dextran), Pecshke UV-X illumination system

Interventional study

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Patients with known keratoconus or pellucid marginal degeneration.

You may not qualify if:

• Age \< 18 years \> 50 years.
• Minimal corneal pachymetry in eye to be treated of \< 400μ.
• Evidence of other corneal disease in the eye to be treated (e.g. Herpes simplex keratitis).
• Women who are pregnant or nursing at the time of the initial treatment.
• Presence of significant central corneal opacity.
• Patients unwilling to not wear rigid contact lenses in the eye to be operated on for at least one month before baseline examination, and for the first six months post-operatively.

Sponsors & Collaborators

• Moorfields Eye Hospital NHS Foundation Trust: lead
• Accuvision Laser Eye Clinics: collaborator
• Carleton Optical Equipment Ltd.: collaborator
• Bon Optics: collaborator
• Sooft Italia: collaborator

Study Sites (1)

Moorfields Eye Department at St George's Hospital

London, London, SW17 0QT, United Kingdom

Location

MeSH Terms

Conditions

Keratoconus

Interventions

Riboflavin; Dextrans

Condition Hierarchy (Ancestors)

Corneal Diseases; Eye Diseases

Intervention Hierarchy (Ancestors)

Flavins; Pteridines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds; Heterocyclic Compounds, 3-Ring; Coenzymes; Enzymes and Coenzymes; Pigments, Biological; Biological Factors; Glucans; Biopolymers; Polymers; Macromolecular Substances; Polysaccharides; Carbohydrates

Study Officials

• Chad K Rostron, MB BS

  Moorfields Eye Hospital NHS Foundation Trust

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER

Study Record Dates

• First Submitted: October 21, 2008
• First Posted: October 22, 2008
• Study Start: October 1, 2008
• Primary Completion: October 1, 2010
• Study Completion: October 1, 2010
• Last Updated: July 21, 2011

Record last verified: 2009-04

Locations

GB (1)