Transepithelial Corneal Cross-linking Using Iontophoresis
Condition: Progressive Keratoconus
MeSH terms: Keratoconus
Study type: Interventional

Summary: 
      The purpose of the present Randomized Clinical Trial (RCT) is to compare the efficacy and
      safety of transepithelial corneal cross-linking using iontophoresis (T-ionto CL) to treat
      progressive keratoconus in comparison with standard cross-linking (standard CL).
    

Detailed description: 
      Keratoconus is a progressive corneal ectatic disease causing visual impairment by inducing
      irregular astigmatism and corneal opacity. This disorder typically begins during the second
      decade of life and, in severe forms, may need a corneal transplantation. Corneal
      cross-linking with riboflavin and UV-A is a procedure intended to halt keratoconus
      progression. It generates additional chemical bonds between stromal proteins in order to
      stiffen the corneal tissue. Standard CL includes epithelial removal and stroma soaking with
      dextran-enriched 0.1% riboflavin solution for 30 minutes before being exposed to
      ultraviolet-A radiation using a 3mW/cm2 lamp for 30 minutes.

      Epithelial debridement exposes the cornea to a risk of side effects, such as pain for the
      first two post-operative days, temporary loss of visual acuity during the first three months,
      and serious complications, such as infection and stromal opacity due to corneal scarring.

      Iontophoresis is a non invasive technique in which a weak electric current is used to enhance
      the penetration of hypotonic 0.1% riboflavin-5-phosphate solution into the corneal stroma
      through the intact epithelium. After iontophoresis, the corneal tissue is irradiated using a
      10 mW/cm2 for 9 minutes (T-ionto CL). From previous experimental work (Lombardo M. et al.
      JCRS 2014 and JCRS 2015), the investigators provided evidence that T-ionto CL increases the
      stiffness of human corneas with results almost comparable with standard CL. The new procedure
      holds the promise to be as effective as the standard procedure while minimizing all the
      related risks. It is object of the present clinical trial to randomize patients with
      progressive keratoconus to T-ionto CL and standard CL and compare efficacy and safety of
      treatments.
    

Intervention name(s): Cross-linking with iontophoresis; Standard corneal cross-linking
Intervention type(s): Device; Device
Intervention description(s): The procedure involves a constant current source and two electrodes. The active electrode is a bath tube, which includes a stainless steel grid, placed into the cup at a minimal distance from the cornea. The reservoir is filled with dextran-free, hypotonic riboflavin-5-phosphate solution. The generator applies a constant current of 1mA for a preset period of 5 min. After the riboflavin administration by iontophoresis, the cornea is irradiated using a UVA lamp of 10mW/cm2 for 9 minutes.; In the standard CL, the epithelium is mechanically removed. Then, a solution of riboflavin is instilled each minute for 30 minutes. Corneas are irradiated using a UVA lamp of 3mW/cm2 for 30 minutes.
Other intervention name(s): Ricrolin+; Ricrolin
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Consecutive patients were randomized, using block randomization model, in one of the arm
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: corneal cross-linking; transepithelial corneal cross-linking; iontophoresis; progressive keratoconus