The advent of minimally invasive glaucoma surgery (MIGS), introduced in 2009, changed the discussion around interventions for this chronic disease. No longer was surgery reserved for late-stage, advanced cases. Low-risk—but, admittedly, low-yield—procedures have flourished in the years since. Now, given all the newer treatment options, baseline features in patients undergoing glaucoma surgery for the first time have changed. Researchers from Italy recently conducted a study to characterize such changes.

According to the researchers’ findings, the percentage of patients in 2021 who received surgery for an early stage of glaucoma was more than double the percentage of patients in 2011 (12.9% vs. 6.1%). Minimally invasive bleb-forming procedures (Xen and Preserflo) have helped fuel this shift, they noted. Photo: Allergan, Glaukos. Click image to enlarge.

A team of ophthalmologists from the University of Pisa analyzed the baseline features of patients who underwent their first glaucoma procedure in either 2011 or 2021. They collected data on patients’ intraocular pressure, visual field parameters, stage of disease and the type of surgery performed. All surgeries were performed by the same two glaucoma specialists.

The availability of MIGS overall and the subset of ab-externo procedures (the Xen gel stent and Preserflo microshunt)—which these authors refer to as minimally invasive bleb surgeries, or MIBS, changed the makeup of glaucoma procedures in a number of ways.

“At our center, with the introduction of new less invasive surgical procedures, especially MIBS, the baseline ophthalmic characteristics of patients undergoing glaucoma surgery have significantly changed over the past decade,” said the researchers in their study. They also noted that the 10-year comparison used “provides a valid timeframe to evaluate the adoption and impact of various surgical techniques in an evolving technological landscape.”

The researchers analyzed data from 455 patients: 230 eyes treated in 2011 and 225 eyes in 2021. One demographic difference noted between the two groups was age. The 2011 group was a bit older than the 2021 patients (72.7 vs. 70.0 years old) and had more advanced visual field mean defect (-16.4dB vs. -13.8dB) and higher IOP (25.9mm Hg vs. 24.9mm Hg). The researchers also noted that severe field loss was more prevalent in the 2011 cases than the ones treated a decade later (74.3% vs. 60.8%).

Procedural trends for glaucoma surgery also changed over the 10-year study period. A total of 211 traditional glaucoma filtering surgeries were performed in 2011, but just 94 were in 2021. Also, MIBS were quite popular among this group, accounting for 58.2% of their glaucoma surgeries in 2021.

This study was limited in its findings due to its retrospective nature. The researchers believe that this introduced the possibility of selection bias and issues related to incomplete data. Since the data collected in this study was solely for the use of comparing surgical techniques as they evolved over a 10-year period, the researchers failed to capture data and evaluate the safety and efficacy of each procedure. This team also did not offer every MIGS procedure commercially available on the market, which led to some discrepancies when comparing surgeries. Furthermore, the surgeons who performed the glaucoma procedures favored standard filtration surgery over most other options, which the researchers noted that this does not reflect the global perception of the technique.

“It seems that the rise in MIBS is changing our approach to surgery, and it will be interesting to determine through future studies whether this trend will continue and have a significant impact on disease management,” concluded the researchers in their study. “This study could be considered a preliminary one for further development of prospective and randomized clinical trials which have the aim to confirm the role and positioning of MIBS in the glaucoma treatment paradigm.”