Association of the prolonged use of anti-glaucoma medications with the surgical failure of ab interno microhook trabeculotomy

Purpose This study examined the perioperative factors affecting surgical success in ab interno microhook trabeculotomy (mu TLO). Methods A total of 146 consecutive patients who underwent mu TLO were included in this retrospective study. We performed Cox proportional hazard modelling by setting surgical success at 1 year as an objective variable. The explanatory variables included age, sex, glaucoma type, preoperative intraocular pressure (IOP), glaucoma drug score, mean deviation (MD) of the Humphrey visual field test, duration of glaucoma drug use, antithrombotic drug use, combined cataract surgery, incision range and diabetes mellitus. Additionally, we performed 1:1 matching using propensity score analysis and compared the perioperative parameters between durations of glaucoma drug use of <4.5 years and >= 4.5 years (50 patients each). We defined surgical success as satisfaction of all three criteria: IOP 5-21 mmHg, IOP reduction of >= 20% from the preoperative IOP and no additional glaucoma surgery. Results The Cox proportional hazard model revealed that a longer duration of anti-glaucoma medication was significantly associated with surgical failure. Propensity score matching analysis showed that the <4.5-year users of anti-glaucoma drugs had significantly higher success rates than the >= 4.5-year users (72% versus 52%; p = 0.04). Conclusions The prolonged use of multiple glaucoma drugs adversely affected the outcome of mu TLO at least at 1 year postoperatively.