Analyzing the Shortcomings of Trabecular Micro-bypass Stents for Surgical Management of Glaucoma

reduction by trabecular procedures like iStent, iStent inject or hydrus combined with cataract surgery versus cataract surgery alone, it was found that trabecular MIGS procedures led to a decrease in IOP by only 1.6-2.3mm Hg (3.8-8.9%) over cataract surgery which alone provided 21-28% IOP reduction at 2 years postsurgery.7 The decrease in medication attributed to these devices alone was 0.4 at 2 years.This report clearly shows that trabecular stents have very minimal additional benefit in terms of IOP lowering, and the impressive IOP drops being used to convince both patients/surgeons to undergo/adopt these procedures are mainly due to the effect of cataract surgery on the anterior chamber angle and improving the facility of outflow.Even this mild IOP reduction may be exaggerated due to industry sponsorship bias as all trials discussed in the above report were industry-sponsored, and nearly all had first or corresponding authors with a financial interest in the specific companies whose device they were evaluating.In addition, many of these studies wash out the medications and then report outcomes.In patients who are on long-term medications, there may be drug tachyphylaxis, and this may reverse after a drug holiday due to an increase in drug-receptor sensitivity.So, even a single drug may be very effective when introduced after a drug holiday and lead to a significant reduction in IOP.This may lead to the trial showing a reduction in the number of medications, which may not be an accurate depiction of the actual outcomes.