Study Examines Demographics of Minimally Invasive Glaucoma Surgery Patients

A study shows that the IOP-lowering implants may be underused for some patients.

Researchers analyzing the Intelligent Research in Sight (IRIS) Registry data, the largest cohort of patients who have had minimally invasive glaucoma surgery (MIGS) in the United States, have found defining demographic and clinical characteristics of those receiving the procedures, according to a study published in Ophthalmology.

The study found that patients who are African American had higher odds of undergoing MIGS than patients who are White. However, it also shows patients of Hispanic heritage and all other ethnicities had lower odds of undergoing MIGS than patients who are White, despite the fact that individuals of Hispanic heritage, like those who are African American, are at higher risk of glaucoma than individuals who are White.  

“Understanding the demographic and clinical characteristics of patients undergoing MIGS procedures may provide insight into patient selection.” according to the investigators, led by Midwest Glaucoma Center,’s Mildred Olivier, MD.

The cohort gathered information about patients in the United States 40 years and older who were diagnosed with primary open angle glaucoma and who had no history of MIGS or cataract surgery undergoing cataract extraction, with or without MIGS, from 2013 to 2017. Researchers assessed age, sex, race-ethnicity, disease severity, insurance type, census region, comorbidity, and cup-to-disc ratio (CDR).

They found that the odds of having a MIGS procedure were greater in those patients who: were older than 60 years, African American, or a Medicare recipient. It also found greater utilization of MIGS for patients in the Midwest or Northeast than in the South. Other variables associated with increased odds of having MIGS were having moderate, instead of mild, glaucoma and a higher CDR. 

The team also reports that women were less likely to undergo MIGS procedures than men. Additionally, patients taking 5 to 7 glaucoma medications were more likely to receive a MIGS implant than those, using 1 to 2 medications. Typically, MIGS devices are recommended for patients with mild to moderate glaucoma.

“This analysis highlights the importance of capturing race-ethnicity data and other pertinent patient characteristics in electronic health records to provide insight into practice patterns. Such data can be used to assess the long-term performance of MIGS and other procedures in various patient populations,” the study says.

The study’s limitations include that the glaucoma stage was based on ICD-10-CM severity codes instead of visual field tests and evaluation of the retinal 228 nerve fiber layer using optical coherence tomography, so investigators could not confirm the accurate assessment of disease stage. The data only represents the ophthalmologists who have registered with IRIS, and those registered might have changed in the years measured. Finally, data were mainly obtained from private ophthalmic practices, so institutions outside of that scope may not be adequately represented in the IRIS data.

The researchers advocate for clinicians to consider “patients who would be appropriate candidates but historically have been underrepresented in their patient selection for MIGS procedures, e.g., female, Hispanic, Medicaid insurance status, and patients with comorbid conditions of hypertension and diabetes. This change in practice pattern could broaden population access to a group of safer procedures that can address IOP and reduce the cost and adherence issues related to glaucoma medications.”


Olivier MMG, Smith O, Croteau-Chonka CC, et al. Demographic and Clinical Characteristics Associated with Minimally Invasive Glaucoma Surgery Use: An IRIS® Registry Retrospective Cohort Analysis. Ophthalmology. 2021. doi: 10.1016/j.ophtha.2021.02.012