Eyeworld

EW MEETING REPORTER 138 October 2015 Reporting from the XXXIII Congress of the ESCRS, September 5–9, Barcelona Reporting from the XXXIII T he first symposium of the EuCornea meeting prior to the start of the Europe- an Society of Cataract & Refractive Surgeons (ESCRS) Congress highlighted crosslink- ing in 2015. David O'Brart, MD, London, compared epi-on vs. epi-off crosslinking procedures. Since the inception of crosslinking, there have been several published case series that have shown the stabilization of a vast majority of cases with few complications, he said. With epi-off crosslinking, there is the poten- tial for severe postoperative pain, blurred vision, and sight-threatening complications. Meanwhile, epi-on crosslinking has less pain with faster visual recovery; less risk of infection; and some reduced risk of stromal scarring, haze, and other complications. However, epi-on crosslinking also runs the risk of being less effective because of poorer lipid solubility. The epithe- lial removal facilitates riboflavin absorption, Dr. O'Brart said. In order for results from epi-on to be com- parable, surgeons need to modify the epithelial permeability. This can be done mechanically, chemically, or electrically. Modification of the riboflavin solution and modification of the application can also help improve the epi-on techniques. Dr. O'Brart referenced a number of studies looking at both epi-off and epi-on crosslinking. Looking at the studies overall, in a literature review of 44 epi-off and 5 epi-on studies, while the visual parameters were roughly the same, in terms of corneal flattening, there were worse effects with epi-on. He thinks that current methods can be improved. There is interesting work being done with epi-on and iontophoresis. All the current iontophoresis proto- cols are 0.1% riboflavin and 1 mA for 5–10 minutes. Epi-on efficacy is limited by stromal riboflavin absorption and epithelial riboflavin masking UV absorption. There are potential chemical enhancers that can be used, but these are often asso- ciated with epithelial damage and limited stroma riboflavin uptake. Modified iontophoretic protocols have increased stromal absorption. The optimization of epi-on protocols requires accurate methodology to assess crosslinking efficacy, optimal riboflavin stroma concentration, and optimum stromal UVA dosage.

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