Iontophoresis-Assisted Rose Bengal and Green Light Corneal Cross-Linking

To evaluate the effects of the application of iontophoresis-assisted rose bengal and green light cross-linking (I-RGX) therapy on enucleated rabbit eyes for corneal biomechanical parameters, dye diffusion rates, and green light levels reaching deep tissues and to compare these parameters with a standard rose bengal and green light cross-linking (RGX) therapy.

Forty-five enucleated rabbit eyes were used in this study. To evaluate biomechanical changes, corneas were divided into the following 4 groups: the control group, the 0.1% rose bengal application group, the RGX group (100 J/cm), and the I-RGX group (100 J/cm). After this, corneal strips were evaluated with a uniaxial extensometer. To assess corneal dye diffusion, postprocedure dye depth was recorded with anterior segment optic coherence tomography. The amount of irradiation passing through the cornea during irradiation with 250 mW/cm irradiation power was measured with a laser power meter at the first, third, and seventh minutes.

In the I-RGX-treated group especially, the mean elastic modulus and corneal stiffness values were about 4.7 times higher when compared with the controls and about 2.2 times higher than those in the RGX group. The rose bengal diffusion depth was 26.63% ± 3.84% of the total corneal thickness in the rose bengal drop group, but this value increased to 42.22% ± 4.77% in the iontophoresis group (<0.001). After iontophoresis, an average of 98% of the 100 J/cm green light was kept in the cornea.

I-RGX is a very useful method for increasing corneal biomechanical strength and is highly effective in increasing the amount of corneal dye diffusion into the cornea while also minimalizing the amount of laser passage reaching deeper tissues.