Standard Corneal Collagen Crosslinking Versus Transepithelial Corneal Crosslinking by Iontophoresis of Riboflavin

Ufa Eye Research Institute

Status: Completed

Conditions: Keratoconus

Treatments: Drug: Riboflavin 0,1%; Procedure: iontophoresis of riboflavin; Device: UFalink; Procedure: epithelium-off; Procedure: Corneal collagen crosslinking; Drug: Dextralink; Device: galvanizator, Potok-1

Study type: Interventional

Funder types: Other

Identifiers

NCT02456961

TCXL-ionto

Details and patient eligibility

About

The standard CXL technique involves removal of the epithelium to enable riboflavin to penetrate into stromal tissue, to avoid epithelial debridement and increasing the patient's comfort and safety transepithelial corneal crosslinking (CXL) was suggested. Iontophoresis of riboflavin is one of approach for riboflavin impregnation.

In this study, the investigators compared the results of standard corneal crosslinking (CXL) and transepithelial CXL via iontophoresis of riboflavin after 24 months follow up.

Enrollment: 126 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Documented progressive KC (by Pentacam and/or corneal topography imaging).
• A clear central cornea.
• A minimal corneal thickness of ≥ 400 µm at the thinnest corneal location (Pentacam imaging).
• Minimal Snellen corrected distance visual acuity of ≥ 0.4.
• Patient age of ≥ 18 years.

Exclusion criteria

• Corneal scarring.
• History of epithelial healing problems.
• History or presence of ocular infection (such as herpes keratitis)
• Pregnancy and/or breastfeeding.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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126 participants in 2 patient groups

Standard epithelium-off CXL

Active Comparator group

Description:

Removing the central 8-10mm of the epithelium and applying a riboflavin solution (0.1% riboflavin-5-phosphate and 20% dextran T-500) to the corneal surface 30 minutes before irradiation and at 5 minutes intervals during the course of a 30 minute exposure to 370 nm UVA with an irradiance of 3 mWcm-2 (UFalink, Russian Federation)

Treatment:

Drug: Dextralink

Device: UFalink

Procedure: epithelium-off

Procedure: Corneal collagen crosslinking

Transepithelial CXL via iontophoresis of riboflavin

Experimental group

Description:

impregnation of the cornea with a riboflavin 0.1% hypotonic solution is performed by using an iontophoresis device (galvanizator; Potok-1, Russian Federation). The passive electrode (anode) was applied to the inferior part of the cervical vertebrae. The active electrode (cathode), a bath tube (glass or plastic - 10-12 ml) is applied to the open eye,then r the tube is taped to the skin of the orbital margins and filled with riboflavin 0.1%. The current intensity is initially 0.2 mA and then gradually increased to 1.0 mA at 0.2 mA for 1 minute at 10-second intervals increments to determine individual tolerance. The total time that the riboflavin administration is 10 minutes. Standard surface UVA irradiation (370 nm, 3 mW/cm2) using UFalink device, (Russian Federation) is then applied at a 5-cm distance for 30 minutes with continuing hypotonic riboflavin drops every 2 minutes

Treatment:

Drug: Riboflavin 0,1%

Procedure: iontophoresis of riboflavin

Device: UFalink

Device: galvanizator, Potok-1

Procedure: Corneal collagen crosslinking