Karen Tiuseco, Hamish Dunn, Samantha Bobba, Paul R Healey

Purpose: Although glaucoma filtering surgery (GFS) with the XEN45 stent promises a faster and safer trabeculectomy, the IOP outcome will still be determined by post-operative wound healing response. Mitomycin-C (MMC) has been used “off-label” to regulate the post-trabeculectomy wound healing response, but no clinical trials exploring the appropriate doses or application technique of adjunctive MMC have been pub- lished for the XEN45. We aimed to determine ini- tial and subsequent changes in usage of MMC in XEN45 GFS users in Australia and New Zealand through the administration of a standardised questionnaire.

Methods: An anonymous structured standardised self-administered questionnaire using Survey Mon- key was sent to all ophthalmologists who had used the XEN45 in Australia and New Zealand prior to the launch of the device in March 2018. The survey was used to ascertain their: experience as glaucoma surgeons, usual MMC dosage and delivery for trabe- culectomy, initial usage of MMC in XEN45 GFS, and any changes in usage of MMC as a result of accumulated experience with the XEN45.
Results: Twenty-six ophthalmologists used the XEN45 at least once prior to March 2018. Very pre- liminary data suggests intratenons injection of MMC was more common in XEN45 implantation. MMC concentration tended to be lower than stan- dard trabeculectomy but total MMC dose tended to increase over the total caseload. Data from the com- plete data set will be presented.
Conclusion: Although GFS with XEN45 has many similarities to standard trabeculectomy, MMC use appears to differ in some important respects. The implications for new surgeon training will be discussed.