The Role of Minimally Invasive Glaucoma Surgery Devices in the Management of Glaucoma

Abstract

Noncompliance is a problem affecting glaucoma patients. Approaches to improve adherence include the use of drug-delivery systems and safer forms of surgery. Minimally invasive glaucoma surgery (MIGS) has reduced complications, particularly in combination with cataract surgery, and with its good intraocular pressure (IOP) reduction may reduce or eliminate glaucoma medications.Glaucoma is a progressive disease and a leading cause of irreversible blindness. Elevated IOP is the most important risk factor, but effective medical management is dependent on patient adherence. This review summarizes the adherence problem in glaucoma and the efforts, including MIGS, to provide effective IOP control that is not dependent on patient compliance.The current understanding of patient adherence to pharmacological treatment of glaucoma is discussed including the challenges facing glaucoma patients. Historical approaches to providing IOP control in a sustained and reliable way are presented culminating in a review of the burgeoning use of MIGS devices.It is estimated that, in the United States, 27% of prescriptions written, across all medications, are not filled or are filled but not taken. For ocular hypotensive medications, even when filled, a large percentage (which varies widely by study) are not instilled as prescribed. To address this problem, methods for sustained drug delivery have been and continue to be developed, as well as surgical and laser approaches. Most recently, MIGS devices have gained popularity because of the ease of implantation during cataract surgery, favorable safety profile, and the possibility for effective and long-lasting IOP lowering, as well as the reduction or elimination of need for IOP-lowering medication.Poor adherence to treatment is relatively common among glaucoma patients and is associated with progression of disease. Recommending MIGS implantation during cataract surgery may offer optometrists a valuable treatment option in managing glaucoma patients, particularly where good adherence is in doubt.

FIGURE 1

Innovation in addressing noncompliance with glaucoma treatment. Recognizing that noncompliance with medical glaucoma therapy is a serious problem affecting a large proportion of glaucoma patients, clinicians and pharmaceutical companies have taken multiple approaches in attempts to improve adherence. Shown is a timeline demonstrating approaches to improve adherence from 1970s to 2010s.

FIGURE 2

Minimally invasive glaucoma surgery (MIGS) devices. MIGS devices are devices that use an ab interno, microincisional approach, create minimal trauma to and disruption of normal anatomy and physiology, and show effective intraocular pressure lowering. MIGS devices should be straightforward, rapid, relatively easy, and appropriate for both glaucoma specialists and general ophthalmologists. Clockwise from top left: CyPass Micro-Stent, iStent Trabecular Micro-bypass Stent, iStent Inject, Hydrus Microstent, XEN Gel Stent.