Despite limited evidence of the long-term safety and effectiveness of minimally invasive glaucoma surgery (MIGS) techniques, the procedures have been a hit with surgeons. New research presented at the ARVO 2021 virtual meeting reports a substantial increase in the performance of MIGS and a decrease in traditional glaucoma surgeries in the United States over the past six years.

The investigative team from Harvard University and Massachusetts Eye and Ear used data from the American Academy of Ophthalmology IRIS registry between the years 2013 and 2018 to calculate the annual number of MIGS and standard glaucoma surgical techniques—either trabeculectomy or glaucoma drainage device (GDD)—performed in the US and then stratified the results by demographics. The investigation also included a secondary analysis of concurrent surgeries and subsequent surgeries for MIGS and standard surgical techniques.

The research paper included 203,574 eyes and 232,537 unique procedures based on ICD-9 and ICD-10 codes for glaucoma.

Considering the number of surgeries, the researchers noted an increase in annual MIGS procedures from roughly 8,000 in 2013 to about 40,000 in 2018, in addition to a reciprocal decrease in standard glaucoma procedures from approximately 16,000 to 14,000 in the same timeframe.

Of note, the number of iStent (Glaukos) procedures nearly tripled during the study period from 14% to 40%. By 2017, the iStent accounted for about 44% of all glaucoma surgeries in the US.

The authors also reported approximately 22,000 (11%) of all eyes received multiple procedures, including about 7,000 (34%) on the same day and roughly 14,000 (66%) on subsequent days.

Endoscopic cyclophotocoagulation (ECP) and iStent were the most common concurrent procedures at 59%, while trabeculectomy and GDD were most often followed by another standard glaucoma surgery.

Subjects receiving either the iStent or endoscopic cyclophotocoagulation were more likely to be female, while those with GDDs were more likely to be younger and male. Individuals who got either the iStent or Xen (Allergan) stent tended to be white, while those receiving GDD, goniotomy or trabeculectomy generally were Black.

The findings highlight the need for further studies that compare the safety and outcomes of novel MIGS vs. traditional surgical treatments for glaucoma, the researchers suggested.