Considerations for Adding Minimally/Microinvasive Glaucoma Surgery (MIGS) to a Planned Cataract Surgery

Glaucoma is a progressive optic neuropathy defined by retinal ganglion cells loss and characteristic visual field loss. It is a leading cause of irreversible blindness and affects over 60 million people worldwide. Its prevalence is estimated to increase to 111.8 million by 2040. Intraocular pressure (IOP) is a major clinically modifiable risk factor for glaucoma. Thus, glaucoma therapy aims to reduce the IOP using medications, lasers (e.g., selective laser trabeculoplasty) or surgery. Historically, surgery has been reserved for advanced glaucoma and in cases with poorly controlled pressure despite medical and laser treatment. For decades, trabeculectomy and tube shunt devices have been the predominant surgical methods for lowering ocular pressure. However, these traditional surgeries are invasive requiring significant manipulation of ocular tissue and have significant post-operative complication rates. Many patients have fallen in the gap of needing more pressure lowering but not enough to justify a higher risk surgery. Fortunately, the landscape of glaucoma surgery has rapidly evolved over the past 20 years with the emergence of minimally/micro- invasive glaucoma surgery (MIGS).  MIGS is often performed as an adjunct to cataract surgery. As such, there is minimal added long-term risk if the procedure is done in the same space as the already planned cataract surgery. This represents a large group of patients, some of whom would not have been considered as glaucoma surgical candidates in the past. The clinician is now faced with the question, “Should I add MIGS to the cataract surgery?” In this paper, we suggest a series of questions to ask about each case in order to help make a patient-centred decision.