In order to overcome the contra-indication of crosslinking corneas with a thickness bordering on 400μm, a number of treatment modifications have been proposed for the treatment of very thin corneas. These include the use of hypo-osmolar riboflavin solutions to swell the cornea to reach the optimum tissue thickness for cross-linking ; the use of transepithelial riboflavin solutions  and/or iontophoresis-assisted riboflavin delivery  to avoid the requirement for removal of the epithelium and maximise the thickness of the tissue; the use of higher riboflavin concentrations to protect the corneal endothelium by reducing the amount of UVA radiation reaching the deeper layers of the tissue ; the use of pachymetry-guided epithelial debridement (‘epithelial island technique’) to selectively remove the epithelium from regions of the cornea with a thickness >400 µm ; the use of a shielding riboflavin-soaked contact lens (‘contact lens-assisted cross-linking’) ; and the use of additional corneal tissue (refractive lenticules) spread over the cornea to thicken the thinnest parts of the tissue prior to cross-linking (‘lenticule assisted cross-linking’) .
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 Sachdev, MS. et al Tailored stromal expansion with a refractive lenticule for crosslinking the ultrathin cornea. J Cataract Refract Surg 2015; 41: 918–923.
Last updated: December 2021