22 January 2021
Anti-fibrotic agent and eye implant failure in toddlers
Published online 23 October 2009
The Ahmed Glaucoma Valve (AGV) is an ocular implant that, via aqueous flow through its tube, can help control intraocular pressure in glaucoma. Over time, however, scar tissue can accumulate at the implant site, impeding flow and eventually causing the AGV to fail. Some surgeons therefore use an antifibrotic agent – mitomycin-C (MMC) - during the implant operation in the hope of minimising scar tissue build up and extending the life of the valve.
In this retrospective study, researchers from the King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia, examined the medical records of 27 patients (31 eyes), of less than two years of age, who underwent the AGV implant procedure. Of these, 16 eyes had MMC while 15 did not.
Contrary to expectations, use of MMC was found to be correlated with a significant increase in the rate of failure of implant at two years post procedure, as well as shorter average survival time and shorter average time without need for additional medication. The researchers speculate that rather than controlling fibrosis, the MMC-induced tissue death stimulated a stronger reactive fibrosis around the AGV, beyond the region the MMC was focally applied, owing to the young children's robust immune response.