CurrentBlue Cross Blue Shield - Rhode IslandPolicy N/A

Aqueous Shunts and Stents for Glaucoma — Medical Coverage Policy

Covers medical necessity and coverage stance for ab externo aqueous shunts and ab interno aqueous stents (MIGS) for treatment of glaucoma for Medicare Advantage and Commercial members of Blue Cross Blue Shield - Rhode Island.

Policy Summary

PayerBlue Cross Blue Shield - Rhode Island

PolicyAqueous Shunts and Stents for Glaucoma — Medical Coverage Policy

Policy CodePolicy N/A

Change TypeNo material changes

Effective DateJan 1, 2020

Next Review DateN/A

Key ActionConsider ab externo shunt or ab interno stent only when medical therapy fails to adequately control intraocular pressure; verify member benefits and covered indications.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

ab externo & ab internodevice approaches discussed

1-2stents permitted with cataract

multipleprocedure codes listed

CyPass withdrawnsafety/regulatory note

Coverage Criteria

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Covered indications

Covered when the following specific conditions are met:

Ab externo aqueous shunts: Insertion of ab externo aqueous shunts approved by the U.S. Food and Drug Administration as a method to reduce intraocular pressure in patients with glaucoma.Medical therapy has failed to adequately control intraocular pressure.

Medicare Advantage: covered when indication met; Commercial: considered medically necessary when medical therapy has failed.

Ab interno aqueous stents (general): Insertion of ab interno aqueous stents approved by the U.S. Food and Drug Administration as a method to reduce intraocular pressure in patients with glaucoma.Medical therapy has failed to adequately control intraocular pressure.

Policy differentiates coverage by plan (Medicare Advantage and Commercial).

Ab interno stents with cataract surgery: Implantation of 1 or 2 FDA‑approved ab interno aqueous stents in conjunction with cataract surgery.Mild-to-moderate open-angle glaucoma while being treated with ocular hypotensive medication; concomitant cataract surgery.

Number of stents specified as 1 or 2 for this indication.

Not covered / Not medically necessary

Ab externo shunts when IOP controlled by meds: Use of an ab externo aqueous shunt for conditions including when intraocular pressure is adequately controlled by medications is not covered for Medicare Advantage Plans and is considered not medically necessary for Commercial Products.Intraocular pressure adequately controlled by medications.

Ab interno stents for other indications: Use of ab interno stents for all other indications (outside those specified above) is not covered for Medicare Advantage Plans and is considered not medically necessary for Commercial Products due to insufficient evidence of benefit.Other indications outside those specified.

Use of aqueous shunts or stents outside the indications explicitly described in this policy is not covered or is considered not medically necessary. Benefits and covered services may vary by contract; providers must refer to the member's Benefit Booklet, Evidence of Coverage, or Subscriber Agreement to confirm whether a proposed use is a covered indication. Examples of non-specified uses include situations where the device would be used for indications other than those listed as medically necessary in this policy.

For Medicare Advantage members, the use of an ab externo aqueous shunt when intraocular pressure is adequately controlled by medications is not covered. For Commercial products the same scenario is considered not medically necessary because available evidence is insufficient to demonstrate benefit for that indication.

Coding

Covered procedure codes when used for a covered indicationCPT | HCPCS | mixedCovered

66183	Insertion of anterior segment aqueous drainage device, without extraocular reservoir; external approach
0253T	Insertion of anterior segment aqueous drainage device, without extraocular reservoir; internal approach, the suprachorodial space into
0191T	Insertion of anterior segment aqueous drainage device, without extraocular reservoir; internal approach, into the trabecular meshwork; initial insertion
0376T	Insertion of anterior segment aqueous drainage device, without extraocular reservoir; internal approach, into the trabecular meshwork; each additional device insertion (List separately in addition to code for primary procedure)
0450T	Insertion of aqueous drainage device, without extraocular reservoir; internal approach, into the subconjunctival space; each additional device (List separately in addition to code for primary procedure)
0449T	Insertion of aqueous drainage device, without extraocular reservoir; internal approach, into the subconjunctival space; initial device
0474T	Insertion of anterior segment aqueous drainage device, with creation of intraocular reservoir; internal approach, into the supraciliary space

Provider Actions and Requirements

Prior Authorization

Not applicable

Note

Medical Therapy Prerequisite

Surgical intervention may be indicated when the target intraocular pressure (IOP) cannot be reached with pharmacologic therapy. Pharmacologic therapy (topical ocular medications) is first-line and may include agents that increase aqueous outflow or decrease aqueous production. Providers should document trials of medical therapy when applicable.

Documentation Required

Benefit Verification and Indication Linkage

Benefits and coverage may vary by group or contract. Verify the member's benefit booklet, Evidence of Coverage, or Subscriber Agreement for applicable surgery coverage and any contract-specific limitations. The procedure codes listed in the policy may be subject to contract-level coverage determinations.

Denial Risk

Noncovered / Not Medically Necessary Indications

Noncovered / Not medically necessary indications: Use of an ab externo aqueous shunt for all other conditions, including in patients with glaucoma when intraocular pressure is adequately controlled by medications, is not covered for BlueCHiP for Medicare (Medicare Advantage) and is considered not medically necessary for Commercial Products. Use of ab interno stents for all other indications (beyond the specified FDA-approved indications and conjunctive cataract procedures described in this policy) is not covered for Medicare Advantage Plans and is considered not medically necessary for Commercial Products due to insufficient evidence of clinical benefit. Document clinical indications and prior medical therapy; lack of such documentation may result in denial.

Ab externo aqueous shunts: not covered for Medicare Advantage; not medically necessary for Commercial Products when IOP is controlled by medications or for other non-specified indications.
Ab interno aqueous stents: not covered for Medicare Advantage for indications other than the FDA-approved uses described; not medically necessary for Commercial Products for unproven indications.
Providers should document failure or inadequacy of medical therapy and linkage to covered codes when submitting claims.

Background

Glaucoma is a progressive optic neuropathy in which elevated intraocular pressure (IOP) is a major modifiable risk factor and can lead to visual field loss and blindness if uncontrolled. First-line therapy for most patients is pharmacologic management with topical ocular hypotensive medications aimed at achieving a target IOP. When target IOP cannot be achieved with medications, surgical options — including traditional procedures (e.g., trabeculectomy or ab externo aqueous shunts) and less invasive approaches (ab interno aqueous stents or MIGS) — are considered to further lower IOP and reduce the risk of vision loss.

Definitions

Ab externo aqueous shunt — definition and examples

DefinitionDevice implanted from outside the eye to shunt aqueous humor and lower intraocular pressure, often creating an external reservoir or channel.

Common examplesAhmed, Baerveldt, Molteno, EX-PRESS (mini‑shunt)

Typical indicationPrimary indication is failed medical or surgical therapy for glaucoma; sometimes used as primary intervention for select conditions (congenital glaucoma, trauma, chemical burn, pemphigoid).

Clinical considerationsThese devices differ by plate size/shape, valve presence, and surgical technique; generally lower hypotony risk versus trabeculectomy but may have worse IOP outcomes and similar annual failure rates (~10%).

Common complicationsCorneal endothelial failure, conjunctival erosion; lower postoperative infection risk compared with trabeculectomy.

Ab interno aqueous stent (MIGS) — definition and examples

DefinitionMinimally invasive devices inserted from within the eye (ab interno) intended to improve aqueous outflow through smaller incisions with less conjunctival manipulation.

Common examplesiStent, Hydrus Microstent, XEN gelatin stent, (earlier) CyPass suprachoroidal stent

Typical useMay be used to reduce IOP and medication burden in mild-to-moderate open‑angle glaucoma and can often be implanted concurrently with cataract surgery (1–2 stents when performed with cataract extraction).

Clinical limitationsSome ab interno stents may be unable to reduce IOP below distal outflow pressure (e.g., <15 mm Hg) and are not indicated when very low IOP is required (advanced glaucoma).

Device considerationsMultiple stents can be implanted to achieve target IOP; most devices do not preclude subsequent trabeculectomy if needed.