There are numerous FDA-approved minimally invasive glaucoma surgery (MIGS) techniques being used by ophthalmologists throughout the United States that are meant to reduce intraocular pressure (IOP) in patients with glaucoma. Trabeculectomy and glaucoma drainage devices (GDD) are still considered the surgical standard of care for the disease, despite potential known complications including endophthalmitis, choroidal hemorrhage or effusion and post-operative incisional scarring. MIGS may offer patients a safer and less invasive treatment option.

In this study, researchers examined usage patterns of MIGS and standard surgical techniques (trabeculectomy or GDDs) for different glaucoma types. They used data from the American Academy of Ophthalmology IRIS Registry from 2013-2018 to measure the proportion of stand-alone, same-day or subsequent day glaucoma surgical techniques performed in each glaucoma diagnosis type.

Of all 203,146 eyes that received glaucoma surgery, open-angle glaucoma (OAG) was most likely to undergo any type of intervention. The most commonly performed MIGS was the iStent microstent, most often done on eyes with OAG and normal tension glaucoma (NTG). The most common standard procedure performed was GDD, most often in secondary glaucoma or other specified glaucoma.

Additional findings include:

• ECP and iStent were the most common concurrent procedures performed, most often for OAG and NTG.

• The vast majority of eyes (90.3%) underwent recurrent standard interventions following initial trabeculectomy or GDD placement.

• ECP was the most common MIGS performed after initial standard surgery, especially for eyes with primary angle-closure (PACG) or secondary glaucoma.

“We demonstrate that the most common glaucoma diagnosis for those undergoing MIGS was OAG,” the authors of the study wrote. “In addition to previous similar analyses, we further contextualize MIGS usage patterns for individual glaucoma types compared to traditional glaucoma surgery; and show significant differences in the types of procedures performed by diagnosis. Those with OAG were disproportionately more likely to receive the iStent vs. all other glaucoma diagnoses.”

The researchers note the potential advantage of combining MIGS procedures in glaucoma management, explaining that “an additional device may augment IOP reduction in mild-moderate disease, rather than a single MIGS device insertion alone.” More research is needed to validate the safety and effectiveness of various MIGS in comparison to standard interventions for each glaucoma type.

Yang SA, Mitchell WG, Hall N, et al. Usage patterns of minimally invasive glaucoma surgery (migs) differ by glaucoma type: iris registry analysis 2013–2018. Ophthalmic Epidemiology. July 26, 2021. Epub ahead of print.