Perez et al. examined the efficacy of mitomycin-C (MMC) on the challenging hypertensive phase (HP) of drainage implants. The investigators demonstrated that subconjunctival MMC, injected over the FP7 Ahmed plate, 25 micrograms for three doses, decreased the incidence of the HP from 55% to 17.6% (P = 0.04). At the one- and two-month postoperative visits, the IOP was significantly lower in the MMC group, but there was no significant difference at six months. However, the need for greater medication burden persisted in the no MMC group.
The main conclusion of the study was the effect of MMC on the HP, but two other important factors include length of time and height of IOP prior to initiating aqueous suppressants.1,2 For example, it is unclear whether the MMC group had aqueous suppressants started sooner as they were likely seen more frequently when they came in for their MMC injections. It is assumed the eyes had similar types of previous glaucoma surgery, but this is not noted in the paper. Considering the nature of wound healing following drainage implants, especially with percentage differences in the neovascular groups, a one-year follow-up would be more desirable.
Subconjunctival injections of MMC seem to be the current trend that most likely represents a way station on the antimetabolite journey.3 It is unknown whether subconjunctival injections are better than the time-honored sponge to deliver the MMC. Moreover, the increasing trend of using low energy CPC/Diode following elevated IOP after a tube shunt may potentially reduce the risk of attendant MMC with tube shunts.(4) In spite of all these factors, this subject deserves a prospective study for it potentially is a game changer for IOP control following drainage implant surgery in valved devices. The authors have highlighted the need for further investigation of MMC with tube shunts and should be congratulated for studying these difficult clinical questions.
This subject deserves a prospective study