CurrentBlue Cross Blue Shield - Rhode IslandPolicy N/A

Viscocanalostomy and Canaloplasty

This policy governs coverage and medical necessity determinations for viscocanalostomy and canaloplasty procedures to reduce intraocular pressure in individuals with glaucoma for Blue Cross Blue Shield - Rhode Island products (Medicare Advantage and Commercial).

Policy Summary

PayerBlue Cross Blue Shield - Rhode Island

PolicyViscocanalostomy and Canaloplasty

Policy CodePolicy N/A

Change TypeNo material changes

Effective DateAug 19, 2014

Next Review DateN/A

Key ActionVerify that medical therapy has failed and that the patient is not a candidate for other IOP‑lowering procedures prior to considering canaloplasty.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

2procedures addressed

66174/66175codes MNT for canaloplasty

Insufficientevidence for viscocanalostomy

31+references

Coverage Criteria for Viscocanalostomy and Canaloplasty

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Canaloplasty - Medicare Advantage Plans and Commercial Products

Covered when ALL of the following are met:

Medical therapy failure: Medical therapy has failed to adequately control intraocular pressure

Surgical candidacy: The individual is not a candidate for any other intraocular pressure–lowering procedure (e.g., trabeculectomy or glaucoma drainage implant) due to a high risk for complications

Coding: Procedure is reported with CPT code 66174 or 66175

Not Medically Necessary / Not Covered Conditions

Viscocanalostomy is not covered / is considered not medically necessary because the evidence is insufficient to determine effects on health outcomes

Canaloplasty other indications: Canaloplasty is not covered / is considered not medically necessary under other conditions (including angle-closure glaucoma) because the evidence is insufficient to determine effects on health outcomes

Angle-closure glaucoma and other indications where clinical evidence is insufficient are explicitly excluded from coverage. Viscocanalostomy is not covered / not medically necessary because the available evidence does not demonstrate improvement in net health outcomes. Similarly, canaloplasty is not covered / considered not medically necessary for other conditions (including angle-closure glaucoma) when evidence is insufficient to support use.

Providers should verify member-specific benefits and eligibility prior to providing services; benefits may vary between groups and contracts and are determined by the member's subscriber agreement or employer agreement. For member-specific information contact the provider call center. When services are covered, bill per applicable CPT coding and payer requirements; do not seek payment from the member when the service is a covered benefit.

The policy does not cover viscocanalostomy (considered not medically necessary). Use of the canaloplasty CPT codes (e.g., 66174, 66175) to report viscocanalostomy is not covered for Medicare Advantage and is considered not medically necessary for Commercial Products. Canaloplasty itself may be covered only when criteria for medical necessity are met and reported with the specified canaloplasty CPT codes.

If a service is determined to be not medically necessary (or is a medically necessary service that is a non-covered benefit), the provider may not charge the member unless the member has been informed in advance and provided written agreement to accept financial responsibility. Verify applicable provisions in your participation and subscriber agreements.

Coding and Procedure Codes

Medically necessary CPT codes for canaloplastyCPTCovered

66174	Transluminal dilation of aqueous outflow canal (eg, canaloplasty); without retention of device or Stent
66175	Transluminal dilation of aqueous outflow canal (eg, canaloplasty); with retention of device or stent

Use of canaloplasty codes for viscocanalostomymixedNot Covered

66174/66175 when used for viscocanalostomy

Not covered for Medicare Advantage Plans and not medically necessary for Commercial Products when used to report viscocanalostomy

Provider Responsibilities and Prior Authorization

Prior Authorization

Prior Authorization / Medical Necessity

Prior authorization is not applicable for this policy. Canaloplasty may be considered medically necessary only after failure of medical therapy and when the member is not a candidate for other intraocular pressure–lowering procedures (e.g., trabeculectomy or glaucoma drainage implant) due to high risk for complications.

Medicare Advantage and Commercial: Canaloplasty considered medically necessary only when ALL criteria met: medical therapy failed to control intraocular pressure; member not candidate for other surgical procedures due to high complication risk.
Canaloplasty and viscocanalostomy are not covered / not medically necessary under all other conditions, including angle-closure glaucoma.

Note

Member Eligibility, Benefits Verification, and Financial Responsibility

Benefits and coverage vary by contract. Refer to the member’s Benefit Booklet, Evidence of Coverage, or Subscriber Agreement for group-specific rules and whether the procedure is a non-covered benefit.

Verify member-specific benefits and eligibility with the provider call center prior to scheduling.
If services are determined to be not medically necessary or are non-covered benefits, providers may not charge the member unless the member is informed in advance and agrees in writing to pay out-of-pocket.
Refer to participation agreement(s) for applicable billing and collection provisions.

Denial Risk

Denial Risk for Unsupported Indications

Canaloplasty is indicated only after failure of medical therapy and when other surgical procedures pose high risk; it is not indicated for angle-closure glaucoma or other unsupported indications.

Denial risk if documentation does not show prior medical therapy failure and reason other procedures are unsuitable.
Viscocanalostomy is considered not covered / not medically necessary.

Background and Scope

Glaucoma is caused by impaired aqueous humor drainage leading to elevated intraocular pressure (IOP), which can damage the optic nerve. Surgical interventions aim to restore or bypass outflow pathways to lower IOP when medical therapy is inadequate. Trabeculectomy is the established filtering surgery used to lower IOP but is associated with potential serious complications related to bleb formation and intraocular penetration. Procedures such as viscocanalostomy and canaloplasty were developed as nonpenetrating or ab externo alternatives intended to dilate Schlemm canal and reduce IOP while minimizing bleb-related complications; canaloplasty uses microcatheter-assisted viscodilation and a tensioning suture to expand the canal circumferentially.

Definitions of Procedures

inv-18: Viscocanalostomy — definition and key features

DefinitionVariant of deep sclerectomy that unroofs and dilates Schlemm canal without penetrating the trabecular meshwork or anterior chamber, using a high-viscosity viscoelastic (eg, sodium hyaluronate) to open the canal and create a passage to a scleral reservoir.

PurposeIntended to lower intraocular pressure while avoiding bleb-related complications associated with trabeculectomy.

Comparative effectivenessMeta-analyses and RCTs show trabeculectomy achieves greater IOP reduction than viscocanalostomy; evidence is insufficient to demonstrate improved net health outcomes for viscocanalostomy.

Relation to canaloplastyPrecursor technique to canaloplasty; differs by focusing on unroofing and localized dilation rather than circumferential microcatheterization and tensioning of the canal.

inv-19: Canaloplasty — definition and key features

DefinitionAb externo procedure that dilates and tensions Schlemm canal circumferentially using an illuminated microcatheter (eg, iTrack™ or OMNI®) and a suture loop to expand the canal along its length.

MechanismMicrocatheterization with viscodilation of the full length of Schlemm canal and placement/tensioning of a suture loop between the canal inner wall and trabecular meshwork to improve aqueous outflow.

Indications and limitsDeveloped for open-angle glaucoma; may not lower IOP below distal outflow system pressures (eg, below ~15 mm Hg) and is not indicated when very low target IOP is required.

Regulatory/devicesDevices cleared by FDA (510(k)): iTrack™ for catheterization and viscodilation (2008) and OMNI® Surgical System cleared for canaloplasty (2021).