Glaucoma is a group of eye diseases that can lead to irreversible vision loss if not managed effectively. It is often associated with elevated pressure inside the eye, known as intraocular pressure (IOP). This increased pressure can gradually damage the optic nerve, which transmits visual information to the brain. Minimally Invasive Glaucoma Surgery (MIGS) is a newer, less invasive surgical option for managing eye pressure compared to traditional procedures.
Understanding Glaucoma and Eye Pressure
Glaucoma is characterized by progressive optic nerve damage, often linked to elevated intraocular pressure (IOP). The eye produces aqueous humor, a fluid that nourishes eye structures. This fluid normally drains through the trabecular meshwork, located where the iris and cornea meet.
If this drainage system becomes inefficient or blocked, aqueous humor accumulates, causing eye pressure to rise. This increased pressure can damage the optic nerve, leading to blind spots and, if untreated, permanent vision loss. While elevated IOP is a risk factor, some glaucoma forms occur with normal eye pressure. Managing IOP is a primary strategy to slow optic nerve damage and preserve vision.
What is MIGS?
MIGS, or Minimally Invasive Glaucoma Surgery, refers to procedures designed to reduce intraocular pressure with less tissue disruption than conventional operations. These procedures use microscopic equipment and tiny incisions. The goal of MIGS is to create new pathways for fluid drainage or enhance existing ones, lowering eye pressure.
MIGS procedures are characterized by small incision size, minimal alteration to eye anatomy, and faster recovery. They improve the natural outflow of fluid from the eye rather than creating a new external drainage system. This approach often leads to a more favorable safety profile compared to traditional incisional glaucoma surgeries.
How MIGS Works: Common Approaches
MIGS procedures primarily target the eye’s natural fluid drainage system to improve outflow and reduce intraocular pressure. One strategy enhances flow through the trabecular meshwork, the eye’s primary drain. Devices like micro-stents are placed within this meshwork or Schlemm’s canal to bypass resistance, allowing aqueous humor to drain into natural collector channels. Other approaches, like goniotomy, involve removing a portion of the trabecular meshwork to open the drainage pathway.
Another mechanism creates new drainage routes for aqueous humor. This can involve diverting fluid into the suprachoroidal space (between the choroid and sclera) or into the subconjunctival space (beneath the conjunctiva). Micro-stents for these pathways provide an alternative fluid exit route. These procedures aim for a moderate reduction in eye pressure.
Some MIGS techniques also reduce aqueous humor production by targeting the ciliary body, the structure responsible for fluid generation. Many MIGS procedures are performed with cataract surgery, leveraging the same small incision used for lens removal, though some are standalone. The choice of procedure depends on the glaucoma type, severity, and patient’s eye anatomy.
Who is a Candidate for MIGS?
MIGS procedures are for individuals with mild to moderate open-angle glaucoma. These patients require a modest reduction in intraocular pressure (IOP) that medications alone cannot control or cause side effects. MIGS is often considered for those already scheduled for cataract surgery, allowing both conditions to be addressed in a single operation.
The decision for MIGS is individualized and determined by an ophthalmologist. While MIGS offers a less invasive option, it is not recommended for patients with advanced glaucoma who need a significant and rapid IOP reduction. For such cases, more traditional glaucoma surgeries are appropriate.
Recovery and Expectations After MIGS
Recovery after MIGS is faster and less complex than traditional glaucoma surgeries, due to smaller incisions and minimal tissue disruption. Patients experience a quicker return to normal daily routines, with visual recovery often aligning with that of cataract surgery when performed together. Patients usually receive antibiotic and anti-inflammatory eye drops for several weeks or months to aid healing and prevent complications.
Temporary blurry vision is common but generally resolves within a few days to a week. A benefit of MIGS is the potential for reduced reliance on glaucoma eye drops. Many patients can decrease their medications, and some may stop them entirely, which can improve quality of life and reduce treatment burden.
However, pressure reduction varies, and not all patients become drop-free. Ongoing follow-up appointments with the ophthalmologist are essential to monitor eye pressure and ensure long-term success.