LCD L38233: Micro-Invasive Glaucoma Surgery (MIGS)

History/Background and/or General Information

Primary open-angle glaucoma (POAG) is a chronic, progressive optic neuropathy in adults in which there is a characteristic acquired atrophy of the optic nerve and loss of retinal ganglion cells and their axons. A risk factor associated with POAG is increased intraocular pressure (IOP) due to a buildup of aqueous fluid within the eye which can lead to visual field loss and optic nerve damage, usually without any associated pain or discomfort. The increased IOP is secondary to an imbalance between aqueous fluid secretion and fluid outflow despite an open angle. Although many patients with POAG present with increased IOP, nearly 40% of those with otherwise characteristic POAG may not have elevated IOP measurements.

The goal in POAG is to reduce the IOP to slow the development of optic nerve damage. The IOP can be reduced by medical treatment or surgery, alone or in combination. When the maximum tolerated medical therapy fails to control progression of glaucomatous optic neuropathy, surgical care is considered the next treatment option.

Traditional External Filtration Surgery

IOP should be lowered by improving outflow of eye fluid. This is the mechanism used by traditional glaucoma surgeries, such as trabeculectomy, or tube shunt surgeries with aqueous drainage implants. These procedures are performed from outside the eye, or an ab externo approach. Trabeculectomy uses the patient’s own sclera to create a fistula to the subconjunctival space over the sclera superiorly. Aqueous drainage implants use silicone/plastic tubing and large plates to shunt aqueous to the subconjunctival space in the equatorial region of the eyeball.

Micro-Invasive or Minimally Invasive Glaucoma Surgery (MIGS)

The term MIGS refers to a group of newer surgical procedures that are performed by using an ab interno (from inside the eye) approach via gonioscopic guidance and involve minimal trauma to ocular tissues. In contrast to external filtration surgeries such as trabeculectomy and aqueous tube shunt, these procedures are categorized as internal filtration surgeries. Compared with traditional filtration surgery, MIGS holds the promise of faster recovery time and less severe complications.

Covered Indications

Glaucoma surgical aqueous drainage devices will be considered medically reasonable and necessary when approved by the FDA and used within accordance of the FDA-approved/cleared indications.

• A single insertion per eye of an anterior segment aqueous drainage device(s) without extraocular reservoir, via internal approach into the trabecular meshwork or with creation of intraocular reservoir into the supraciliary space is considered medically reasonable and necessary in conjunction with cataract surgery for the treatment of adults with mild or moderate open-angle glaucoma and a cataract when the individual is currently being treated with an ocular hypotensive medication.

• A single insertion per eye of an aqueous drainage device(s) without extraocular reservoir, via internal approach into the subconjunctival space is considered medically reasonable and necessary as a stand- alone treatment for refractory glaucoma, defined as prior failure of filtering/cilioablative procedure and/or uncontrolled IOP (progressive damage and/or mean diurnal medicated IOP greater than or equal to 20 mm Hg) on maximally tolerated medical therapy (i.e., greater than or equal to 4 classes of topical IOP-lowering medications, or fewer in the case of tolerability or efficacy issues).

Limitations

The following are considered not medically reasonable and necessary:

• Glaucoma drainage devices that do not have FDA approval/clearance and/or devices that have been recalled.

• Glaucoma drainage devices used outside of the FDA approval/clearance.

• Insertion of an anterior segment aqueous drainage device without extraocular reservoir, via internal approach into the suprachoroidal space.

• Additional insertions of anterior segment aqueous drainage device(s) without extraocular reservoir, via internal approach into the trabecular meshwork.

• Additional insertions of aqueous drainage device(s) without extraocular reservoir, via internal approach into the subconjunctival.

• A single insertion of an FDA-approved/cleared anterior segment aqueous drainage device(s) without extraocular reservoir, via internal approach into the trabecular meshwork or with creation of intraocular reservoir via internal approach into the supraciliary space not performed in conjunction with cataract surgery.

• Goniotomy procedure performed in conjunction with the insertion of a glaucoma drainage device. Routine performance of goniotomy with insertion of a glaucoma drainage device may be subject to focused medical review.

• Trabeculectomy procedure performed in conjunction with the insertion of a glaucoma drainage device. Routine performance may be subject to focused medical review.

• Insertion of glaucoma drainage device(s) (i.e., one or two microstents) into the trabecular meshwork or into the supraciliary space are limited to one delivery system per eye when performed in conjunction with cataract surgery and when the medically reasonable and necessary criteria as stated above are met.

• Additional delivery system use for device insertions on one eye is considered not medically reasonable and necessary.

• Insertion of glaucoma drainage device(s) into the subconjunctival space are limited to one insertion per eye per day when the medically reasonable and necessary criteria as stated above are met.

• Additional device insertions are considered not medically reasonable and necessary.

As published in the CMS IOM Publication 100-08, Medicare Program Integrity Manual , Chapter 13, Section 13.5.4, an item or service may be covered by a contractor LCD if it is reasonable and necessary under the Social Security Act Section 1862 (a)(1)(A). Contractors shall determine and describe the circumstances under which the item or service is considered reasonable and necessary.

Provider Qualifications

Services will be considered medically reasonable and necessary only if performed by appropriately trained providers. This training and expertise must have been acquired within the frame work of an accredited residency and/or fellowship program in the applicable specialty/subspecialty or must reflect extensive continued medical education activities. If these skills have been acquired by way of continued medical education, the courses must be comprehensive, offered or sponsored or endorsed by an academic institution in the United States and/or by the applicable specialty /subspecialty society in the United States, and designated by the American Medical Association (AMA) as Category I Credit.

• Provider Specialties

• Insertion of glaucoma drainage devices addressed in this LCD must be performed by a qualified physician (MD or DO) who is a board certified ophthalmologist having completed a residency and/or fellowship program and maintains ongoing certification in ophthalmology.

• In addition, insertion of a substitute standalone drainage device into the subconjunctival space without associated cataract extraction must be performed by an ophthalmologist with experience with trabeculectomy and bleb management.

Notice: Services performed for any given diagnosis must meet all of the indications and limitations stated in this LCD, the general requirements for medical necessity as stated in CMS payment policy manuals, any and all existing CMS national coverage determinations, and all Medicare payment rules.

The redetermination process may be utilized for consideration of services performed outside of the reasonable and necessary requirements in this LCD.

Published pivotal trials for FDA Approved/Cleared Glaucoma Drainage Devices:

• iStent® Study Group

A prospective, randomized, open-label, controlled multicenter clinical trial to assess the safety and efficacy of the iStent trabecular micro-bypass stent (Glaukos Corporation, Laguna Hills, CA) in combination with cataract surgery in subjects with mild to moderate open-angle glaucoma was conducted. 1 A total of 240 eyes with mild to moderate open-angle glaucoma with IOP less than or equal to 24 mmHg controlled on 1 to 3 medications were randomized to undergo cataract surgery with iStent implantation (treatment group) or cataract surgery only (control). The study results met the primary outcome, with 72% of treatment eyes versus 50% of control eyes achieving the criterion (P less than 0.001). At 1 year, IOP in both treatment groups was statistically significantly lower from baseline values. Sixty-six percent of treatment eyes versus 48% of control eyes achieved greater than or equal to 20% IOP reduction without medication (P equal to 0.003). The overall incidence of adverse events was similar between groups with no unanticipated adverse device effects. The authors concluded that pressure reduction on fewer medications was clinically and statistically significantly better 1 year after stent plus cataract surgery versus cataract surgery alone, with an overall safety profile similar to that of cataract surgery alone. TRIAL REGISTRATION: ClinicalTrials.gov NCT00323284.

• iStent® Study Group 2 year follow-up