Corneal Crosslinking Treatment Study

Progressive Keratoconus Clinical Trial

Official title:

Prospective Randomised Corneal Crosslinking Study

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT04427956
• Other study ID #: DNR2015/373
• Status: Active, not recruiting
• Phase: Phase 4
• Start date: May 23, 2017
• Est. completion date: November 1, 2024

Study information

• Verified date: May 2023
• Source: Region Skane
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Three different protocols for inducing corneal crosslinks in subjets with progressive keratoconus will be evaluated in this randomised clinical study.

Description:

Riboflavin does not penetrate the intact corneal epithelium. Corneal cross linking (CXL) is typically performed using the so-called "Dresden protocol". The Dresden protocol states 30 minutes of UVA-radiation (3mW/cm2) but a 10 minute irradiation protocol (9mW/cm2) is frequently used. Both of the protocols involve mechanical removal of the epithelium over the central 8 mm of the corneal surface. The first days after treatment therefore involves some degree of pain, often intense, and the presence of a healing epithelial defect may be associated with development of infiltrates in the cornea. A number of approaches have been evaluated in order to promote riboflavin penetration through the intact epithelium, of which iontophoresis appears most promising. Keratoconic corneas are thin at the cone location and sometimes it is difficult to maintain the safety margin of 400 microns during corneal crosslinking. Instead of using isotonic standard riboflavin, a swelling effect of the cornea can be obtained by using hypotonic riboflavin. However, the latter has been indicated as less effective in the process of inducing cross links.

Eighty-one of 81 patients of various degrees of keratoconus will be randomised to one of the following groups: 1) CXL (UVA 9mW/cm2) using isotonic riboflavin, or 2) CXL (UVA 9mW/cm2) using hypotonic riboflavin or 3) Iontophoresis with Ricrolin with following CXL (UVA 9mW/cm2).

Hypothesis:

i) CXL with hypotonic riboflavin or CXL with Ricrolin administered by iontophoresis or CXL with isotonic riboflavin is non-inferior compared to standard CXL with isotonic riboflavin.

ii) The morphological structure post-CXL in the three different groups will be similar without any significant differences.

The iontophoresis-assisted treatment arm has been interrupted due to low efficacy in halting disease progression. The results have been published.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 54
• Est. completion date: November 1, 2024
• Est. primary completion date: November 1, 2024
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Progress in keratoconic eye. We define progress as an increase in Kmax of 1.0 diopter in 1 year or 0.5 diopter in 6 months. This increase in Kmax will be accepted as progression if concomitant changes tomographic parameters.

Exclusion Criteria:

• Concurrent ocular infection or corneal disease other than keratoconus.

• Pregnancy.

• Treatment with Isotretinoin.

Related Conditions & MeSH terms

• Keratoconus
• Progressive Keratoconus

Intervention

Procedure:
• Corneal crosslinking: CXL (UVA 9mW/cm2)
CXL treatment with UVA-radiation (9mW/cm2) with a 10 minute irradiation protocol.

Drug:
• Isotonic riboflavin
CXL protocol with isotonic riboflavin
• Hypotonic riboflavin
CXL protocol with hypotonic riboflavin

Procedure:
• Iontophoresis
CXL protocol with iontophoresis and ricrolin

Locations

Country	Name	City	State
Sweden	Skåne University Hospital	Lund	Skåne

Sponsors (1)

Lead Sponsor	Collaborator
Region Skane

Country where clinical trial is conducted

Sweden, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Postoperative change in visual acuity	Uncorrected visual acuity (UCVA) and best spectacle corrected visual acuity (BSCVA)	Patients will be evaluated 1, 6, 12 and 24 months after treatment.
Primary	Postoperative change in Kmax	Maximum corneal steepness	Patients will be evaluated 1, 6, 12 and 24 months after treatment.
Secondary	Postoperative change in astigmatism	Corneal astigmatism	Patients will be evaluated 1, 6, 12 and 24 months after treatment.
Secondary	postoperative change in corneal nerve cell density	Corneal nerve cell density will be evaluated using confocal microscopy	Confocal microscopy will be performed at 6 and 12 months.
Secondary	Postoperative change in Keratocyte cell density	Keratocyte cell density will be evaluated using confocal microscopy	Confocal microscopy will be performed at 6 and 12 months.
Secondary	Postoperative change in endothelial cell count	Endothelial cell count will be evaluated using confocal microscopy	Confocal microscopy will be performed at 6 and 12 months.
Secondary	Postoperative change in demarcation lines	Identification of the demarcation lines with confocal microscopy will help establishing how deep was the effect of the CXL treatment.	Confocal microscopy will be performed at 6 and 12 months.
Secondary	Postoperative change in the corneal thickness during CXL treatment	Corneal pachymetry is the process of measuring the thickness of the cornea	Corneal pachymetry will be evaluated before and then every 5 minutes during 30 minutes under CXL treatment.