Micro invasive glaucoma surgery is an emerging glaucoma treatment option for patients who want to decrease their medication burden and avoid conventional glaucoma filtration surgery risks and complications.
Glaucoma is a disease that causes progressive impairment to the fiber (optic nerve), which carries visual impressions from the eye to the brain. It's usually associated with high IOP and often manifests as loss of peripheral vision and can progress to central vision loss and permanent blindness.
MIGS is a term used to refer to a group of surgeries that work by using microscopic-sized equipment and tiny surgical cuts. They share five characteristics:
- Minimally invasive procedure to the target tissue
- Quick recovery with the least effect on the quality of life of the patient
- Inside the eye (ab-interno) approach through a precise cut in the cornea
- High safety profile without severe complications associated with other glaucoma procedures
- Lower the internal eye pressure or intraocular pressure (IOP), by improving the outflow of the aqueous humor, the inner eye fluid
MIGS may enable the eye surgeon to lower the IOP and reduce the burden of eye drop use. However, they don't preclude the possibility of more traditional surgical glaucoma treatments in the future.
Also Known As
- Minimally Invasive Glaucoma Surgeries
Preparation & Expectation Before Surgery
MIGS is a new category of glaucoma treatment and patients must find a surgeon who can help them understand the options and evaluate the benefits and risks. S/he will take a detailed patient medical history, including prescriptions, and conduct a comprehensive eye exam to determine if MIGS is a viable treatment. Many ophthalmologists don't recommend MIGS procedures for patients with advanced glaucoma.
Types, Purpose & Procedure
Typically, MIGS is conducted by using precision lasers and microscopic-sized implants or equipment. The procedures are faster, cause less tissue trauma and result in a more rapid visual recovery than conventional glaucoma surgery. Most of the MIGS procedures are performed along with cataract surgery, in patients with mild to moderate glaucoma and visually significant cataracts, while some can be done as independent operations.
MIGS devices and procedures include:
- Ab-Interno canaloplasty - A method to insert a tiny drainage device to open the eye's natural drainage system.
- Kahook dual blade - A micro-engineered single-use blade that makes parallel cuts to extract a part of the eye's drainage system to improve fluid flow.
- Endocyclophotocoagulation - A surgical technique that uses precision lasers to treat the eye parts that create humor so that they produce less fluid.
- The trabectome - An electrocautery implant that lowers the IOP by taking out a piece of the trabecular meshwork, the eye's drainage tissue. It involves a quick procedure that can be combined with cataract surgery.
- iStent - It's one of the smallest implantable devices approved by the FDA. The implant is about a third of a rice grain in size. It's placed in the eye's drainage system to make a permanent opening that improves the fluid outflow, lowers, and controls the eye pressure.
Many more MIGS procedures and devices are being developed or in clinical trials awaiting FDA approval.
Risks, Side Effects & Complications
Generally, MIGS procedures involve shorter surgical time, which makes them safer than conventional surgeries. The most common risk is some bleeding after the operation.
The side effects may include temporary increased sensitivity to light and blurred vision caused by anesthesia, which should resolve in a day or two.
Scarring over the treated area is the most common complication associated with MIGS. It's essential to note that there are new procedures, and there is limited information about their long-term risks and complications.
After Care, Recovery & Results
Depending on the MIGS procedure, the surgeon may prescribe medication including steroid and antibiotic eye drops, to prevent scarring and inflammation. S/he will advise the patient about their glaucoma medications, and follow-up visits will depend on the condition of the patient.
MIGS procedures are a new, exciting and evolving glaucoma treatment option. It also presents a challenge because new devices and methods are being continuously developed, and they differ in terms of their safety and efficacy profile. It can make it challenging to evaluate the therapeutic options since it takes five to ten years to learn more about the long-term effectiveness of a procedure. Thus, the patient should consult an experienced surgeon for guidance.