223 Form

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Medical Policy Aqueous Shunts and Stents for Glaucoma Table of Contents • Policy: Commercial • Coding Information
• Information Pertaining to All Policies
• Policy: Medicare • Description
• References
• Authorization Information • Policy History

Policy Number: 223

BCBSA Reference Number: 9.03.21 (For Plan internal use only) Related Policies
• Ophthalmologic Techniques that Evaluate the Posterior Segment for Glaucoma,#053 • Viscocanalostomy and Canaloplasty, #372 Policy Commercial Members: Managed Care (HMO and POS), PPO, and Indemnity

Insertion of ab externo aqueous stents approved by the U.S. Food and Drug Administration may be considered MEDICALLY NECESSARY as a method to reduce intraocular pressure in individuals with glaucoma where medical therapy has failed to adequately control intraocular pressure.

Use of an ab externo aqueous shunt for all other conditions, including in individuals with glaucoma when intraocular pressure is adequately controlled by medications, is considered INVESTIGATIONAL.

Insertion of ab interno aqueous stents approved by the Food and Drug Administration as a method to reduce intraocular pressure in individuals with glaucoma where medical therapy has failed to adequately control intraocular pressure, is considered MEDICALLY NECESSARY.

Implantation of 1 or 2 Food and Drug Administration-approved interno stents in conjunction with cataract surgery may be considered MEDICALLY NECESSARY in individuals with mild- to-moderate open-angle glaucoma treated with ocular hypotensive medication.

Use of ab interno stents for all other conditions is considered INVESTIGATIONAL.

Prior Authorization Information
Inpatient • For services described in this policy, precertification/preauthorization IS REQUIRED for all products if the procedure is performed inpatient.
Outpatient • For services described in this policy, see below for products where prior authorization might be required if the procedure is performed outpatient.

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Outpatient Commercial Managed Care (HMO and POS) Prior authorization is not required. Commercial PPO and Indemnity Prior authorization is not required. CPT Codes / HCPCS Codes / ICD Codes Inclusion or exclusion of a code does not constitute or imply member coverage or provider reimbursement. Please refer to the member’s contract benefits in effect at the time of service to determine coverage or non-coverage as it applies to an individual member.

Providers should report all services using the most up-to-date industry-standard procedure, revenue, and diagnosis codes, including modifiers where applicable.

The following codes are included below for informational purposes only; this is not an all-inclusive list.

The above medical necessity criteria MUST be met for the following codes to be covered for Commercial Members: Managed Care (HMO and POS), PPO, and Indemnity:
CPT Codes CPT
codes:

Code Description 0253T
Insertion of anterior segment aqueous drainage device, without extraocular reservoir; into the subarachnoid space
0449T Insertion of aqueous drainage device, without extraocular reservoir, internal approach, into the subconjunctival space; initial device 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) 0671T Insertion of anterior segment aqueous drainage device into the trabecular meshwork, without external reservoir, and without concomitant cataract removal, one or more 66179 Aqueous shunt to extraocular equatorial plate reservoir, external approach; without graft 66180 Aqueous shunt to extraocular reservoir (eg, Molteno, Schocket, Denver-Krupin) with graft 66183 Insertion of anterior segment aqueous drainage device, without extraocular reservoir, external approach 66989 Extracapsular cataract removal with insertion of intraocular lens prosthesis (1-stage procedure), manual or mechanical technique (eg, irrigation and aspiration or phacoemulsification), complex, requiring devices or techniques not generally used in routine cataract surgery (eg, iris expansion device, suture support for intraocular lens, or primary posterior capsulorrhexis) or performed on patients in the amblyogenic developmental stage; with insertion of intraocular (eg, trabecular meshwork, supraciliary, suprachoroidal) anterior segment aqueous drainage device, without extraocular reservoir, internal approach, one or more 66991 Extracapsular cataract removal with insertion of intraocular lens prosthesis (1 stage procedure), manual or mechanical technique (eg, irrigation and aspiration or phacoemulsification); with insertion of intraocular (eg, trabecular meshwork, supraciliary, suprachoroidal) anterior segment aqueous drainage device, without extraocular reservoir, internal approach, one or more

HCPCS Codes HCPCS codes:

Code Description C1783 Ocular implant, aqueous drainage assist device L8612 Aqueous shunt

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The following ICD Diagnosis Codes are considered medically necessary when submitted with the CPT and/or HCPCS codes above if medical necessity criteria are met:

ICD-10 Diagnosis Codes ICD-10-CM Diagnosis codes: Code Description H40.001 Preglaucoma, unspecified, right eye H40.002 Preglaucoma, unspecified, left eye H40.003 Preglaucoma, unspecified, bilateral H40.009 Preglaucoma, unspecified, unspecified eye H40.011 Open angle with borderline findings, low risk, right eye H40.012 Open angle with borderline findings, low risk, left eye H40.013 Open angle with borderline findings, low risk, bilateral H40.019 Open angle with borderline findings, low risk, unspecified eye H40.021 Open angle with borderline findings, high risk, right eye H40.022 Open angle with borderline findings, high risk, left eye H40.023 Open angle with borderline findings, high risk, bilateral H40.029 Open angle with borderline findings, high risk, unspecified eye H40.031 Anatomical narrow angle, right eye H40.032 Anatomical narrow angle, left eye H40.033 Anatomical narrow angle, bilateral H40.039 Anatomical narrow angle, unspecified eye H40.041 Steroid responder, right eye H40.042 Steroid responder, left eye H40.043 Steroid responder, bilateral H40.049 Steroid responder, unspecified eye H40.051 Ocular hypertension, right eye H40.052 Ocular hypertension, left eye H40.053 Ocular hypertension, bilateral H40.059 Ocular hypertension, unspecified eye H40.061 Primary angle closure without glaucoma damage, right eye H40.062 Primary angle closure without glaucoma damage, left eye H40.063 Primary angle closure without glaucoma damage, bilateral H40.069 Primary angle closure without glaucoma damage, unspecified eye H40.10x0 Unspecified open-angle glaucoma, stage unspecified H40.10x1 Unspecified open-angle glaucoma, mild stage H40.10x2 Unspecified open-angle glaucoma, moderate stage H40.10x3 Unspecified open-angle glaucoma, severe stage H40.10x4 Unspecified open-angle glaucoma, indeterminate stage H40.1110 Primary open-angle glaucoma, right eye, stage unspecified H40.1111 Primary open-angle glaucoma, right eye, mild stage H40.1112 Primary open-angle glaucoma, right eye, moderate stage H40.1113 Primary open-angle glaucoma, right eye, severe stage H40.1114 Primary open-angle glaucoma, right eye, indeterminate stage H40.1120 Primary open-angle glaucoma, left eye, stage unspecified H40.1121 Primary open-angle glaucoma, left eye, mild stage H40.1122 Primary open-angle glaucoma, left eye, moderate stage H40.1123 Primary open-angle glaucoma, left eye, severe stage H40.1124 Primary open-angle glaucoma, left eye, indeterminate stage H40.1130 Primary open-angle glaucoma, bilateral, stage unspecified

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H40.1131 Primary open-angle glaucoma, bilateral, mild stage H40.1132 Primary open-angle glaucoma, bilateral, moderate stage H40.1133 Primary open-angle glaucoma, bilateral, severe stage H40.1134 Primary open-angle glaucoma, bilateral, indeterminate stage H40.1190 Primary open-angle glaucoma, unspecified eye, stage unspecified H40.1191 Primary open-angle glaucoma, unspecified eye, mild stage H40.1192 Primary open-angle glaucoma, unspecified eye, moderate stage H40.1193 Primary open-angle glaucoma, unspecified eye, severe stage H40.1194 Primary open-angle glaucoma, unspecified eye, indeterminate stage H40.1210 Low-tension glaucoma, right eye, stage unspecified H40.1211 Low-tension glaucoma, right eye, mild stage H40.1212 Low-tension glaucoma, right eye, moderate stage H40.1213 Low-tension glaucoma, right eye, severe stage H40.1214 Low-tension glaucoma, right eye, indeterminate stage H40.1220 Low-tension glaucoma, left eye, stage unspecified H40.1221 Low-tension glaucoma, left eye, mild stage H40.1222 Low-tension glaucoma, left eye, moderate stage H40.1223 Low-tension glaucoma, left eye, severe stage H40.1224 Low-tension glaucoma, left eye, indeterminate stage H40.1230 Low-tension glaucoma, bilateral, stage unspecified H40.1231 Low-tension glaucoma, bilateral, mild stage H40.1232 Low-tension glaucoma, bilateral, moderate stage H40.1233 Low-tension glaucoma, bilateral, severe stage H40.1234 Low-tension glaucoma, bilateral, indeterminate stage H40.1290 Low-tension glaucoma, unspecified eye, stage unspecified H40.1291 Low-tension glaucoma, unspecified eye, mild stage H40.1292 Low-tension glaucoma, unspecified eye, moderate stage H40.1293 Low-tension glaucoma, unspecified eye, severe stage H40.1294 Low-tension glaucoma, unspecified eye, indeterminate stage H40.1310 Pigmentary glaucoma, right eye, stage unspecified H40.1311 Pigmentary glaucoma, right eye, mild stage H40.1312 Pigmentary glaucoma, right eye, moderate stage H40.1313 Pigmentary glaucoma, right eye, severe stage H40.1314 Pigmentary glaucoma, right eye, indeterminate stage H40.1320 Pigmentary glaucoma, left eye, stage unspecified H40.1321 Pigmentary glaucoma, left eye, mild stage H40.1322 Pigmentary glaucoma, left eye, moderate stage H40.1323 Pigmentary glaucoma, left eye, severe stage H40.1324 Pigmentary glaucoma, left eye, indeterminate stage H40.1330 Pigmentary glaucoma, bilateral, stage unspecified H40.1331 Pigmentary glaucoma, bilateral, mild stage H40.1332 Pigmentary glaucoma, bilateral, moderate stage H40.1333 Pigmentary glaucoma, bilateral, severe stage H40.1334 Pigmentary glaucoma, bilateral, indeterminate stage H40.1390 Pigmentary glaucoma, unspecified eye, stage unspecified H40.1391 Pigmentary glaucoma, unspecified eye, mild stage H40.1392 Pigmentary glaucoma, unspecified eye, moderate stage H40.1393 Pigmentary glaucoma, unspecified eye, severe stage H40.1394 Pigmentary glaucoma, unspecified eye, indeterminate stage H40.1410 Capsular glaucoma with pseudoexfoliation of lens, right eye, stage unspecified H40.1411 Capsular glaucoma with pseudoexfoliation of lens, right eye, mild stage

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H40.1412 Capsular glaucoma with pseudoexfoliation of lens, right eye, moderate stage H40.1413 Capsular glaucoma with pseudoexfoliation of lens, right eye, severe stage H40.1414 Capsular glaucoma with pseudoexfoliation of lens, right eye, indeterminate stage H40.1420 Capsular glaucoma with pseudoexfoliation of lens, left eye, stage unspecified H40.1421 Capsular glaucoma with pseudoexfoliation of lens, left eye, mild stage H40.1422 Capsular glaucoma with pseudoexfoliation of lens, left eye, moderate stage H40.1423 Capsular glaucoma with pseudoexfoliation of lens, left eye, severe stage H40.1424 Capsular glaucoma with pseudoexfoliation of lens, left eye, indeterminate stage H40.1430 Capsular glaucoma with pseudoexfoliation of lens, bilateral, stage unspecified H40.1431 Capsular glaucoma with pseudoexfoliation of lens, bilateral, mild stage H40.1432 Capsular glaucoma with pseudoexfoliation of lens, bilateral, moderate stage H40.1433 Capsular glaucoma with pseudoexfoliation of lens, bilateral, severe stage H40.1434 Capsular glaucoma with pseudoexfoliation of lens, bilateral, indeterminate stage H40.1490 Capsular glaucoma with pseudoexfoliation of lens, unspecified eye, stage unspecified H40.1491 Capsular glaucoma with pseudoexfoliation of lens, unspecified eye, mild stage H40.1492 Capsular glaucoma with pseudoexfoliation of lens, unspecified eye, moderate stage H40.1493 Capsular glaucoma with pseudoexfoliation of lens, unspecified eye, severe stage H40.1494 Capsular glaucoma with pseudoexfoliation of lens, unspecified eye, indeterminate stage H40.151 Residual stage of open-angle glaucoma, right eye H40.152 Residual stage of open-angle glaucoma, left eye H40.153 Residual stage of open-angle glaucoma, bilateral H40.159 Residual stage of open-angle glaucoma, unspecified eye H40.20x0 Unspecified primary angle-closure glaucoma, stage unspecified H40.20x1 Unspecified primary angle-closure glaucoma, mild stage H40.20x2 Unspecified primary angle-closure glaucoma, moderate stage H40.20x3 Unspecified primary angle-closure glaucoma, severe stage H40.20x4 Unspecified primary angle-closure glaucoma, indeterminate stage H40.211 Acute angle-closure glaucoma, right eye H40.212 Acute angle-closure glaucoma, left eye H40.213 Acute angle-closure glaucoma, bilateral H40.219 Acute angle-closure glaucoma, unspecified eye H40.2210 Chronic angle-closure glaucoma, right eye, stage unspecified H40.2211 Chronic angle-closure glaucoma, right eye, mild stage H40.2212 Chronic angle-closure glaucoma, right eye, moderate stage H40.2213 Chronic angle-closure glaucoma, right eye, severe stage H40.2214 Chronic angle-closure glaucoma, right eye, indeterminate stage H40.2220 Chronic angle-closure glaucoma, left eye, stage unspecified H40.2221 Chronic angle-closure glaucoma, left eye, mild stage H40.2222 Chronic angle-closure glaucoma, left eye, moderate stage H40.2223 Chronic angle-closure glaucoma, left eye, severe stage H40.2224 Chronic angle-closure glaucoma, left eye, indeterminate stage H40.2230 Chronic angle-closure glaucoma, bilateral, stage unspecified H40.2231 Chronic angle-closure glaucoma, bilateral, mild stage H40.2232 Chronic angle-closure glaucoma, bilateral, moderate stage H40.2233 Chronic angle-closure glaucoma, bilateral, severe stage H40.2234 Chronic angle-closure glaucoma, bilateral, indeterminate stage H40.2290 Chronic angle-closure glaucoma, unspecified eye, stage unspecified H40.2291 Chronic angle-closure glaucoma, unspecified eye, mild stage H40.2292 Chronic angle-closure glaucoma, unspecified eye, moderate stage H40.2293 Chronic angle-closure glaucoma, unspecified eye, severe stage H40.2294 Chronic angle-closure glaucoma, unspecified eye, indeterminate stage

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H40.231 Intermittent angle-closure glaucoma, right eye H40.232 Intermittent angle-closure glaucoma, left eye H40.233 Intermittent angle-closure glaucoma, bilateral H40.239 Intermittent angle-closure glaucoma, unspecified eye H40.241 Residual stage of angle-closure glaucoma, right eye H40.242 Residual stage of angle-closure glaucoma, left eye H40.243 Residual stage of angle-closure glaucoma, bilateral H40.249 Residual stage of angle-closure glaucoma, unspecified eye H40.30x0 Glaucoma secondary to eye trauma, unspecified eye, stage unspecified H40.30x1 Glaucoma secondary to eye trauma, unspecified eye, mild stage H40.30x2 Glaucoma secondary to eye trauma, unspecified eye, moderate stage H40.30x3 Glaucoma secondary to eye trauma, unspecified eye, severe stage H40.30x4 Glaucoma secondary to eye trauma, unspecified eye, indeterminate stage H40.31x0 Glaucoma secondary to eye trauma, right eye, stage unspecified H40.31x1 Glaucoma secondary to eye trauma, right eye, mild stage H40.31x2 Glaucoma secondary to eye trauma, right eye, moderate stage H40.31x3 Glaucoma secondary to eye trauma, right eye, severe stage H40.31x4 Glaucoma secondary to eye trauma, right eye, indeterminate stage H40.32x0 Glaucoma secondary to eye trauma, left eye, stage unspecified H40.32x1 Glaucoma secondary to eye trauma, left eye, mild stage H40.32x2 Glaucoma secondary to eye trauma, left eye, moderate stage H40.32x3 Glaucoma secondary to eye trauma, left eye, severe stage H40.32x4 Glaucoma secondary to eye trauma, left eye, indeterminate stage H40.33x0 Glaucoma secondary to eye trauma, bilateral, stage unspecified H40.33x1 Glaucoma secondary to eye trauma, bilateral, mild stage H40.33x2 Glaucoma secondary to eye trauma, bilateral, moderate stage H40.33x3 Glaucoma secondary to eye trauma, bilateral, severe stage H40.33x4 Glaucoma secondary to eye trauma, bilateral, indeterminate stage H40.40x0 Glaucoma secondary to eye inflammation, unspecified eye, stage unspecified H40.40x1 Glaucoma secondary to eye inflammation, unspecified eye, mild stage H40.40x2 Glaucoma secondary to eye inflammation, unspecified eye, moderate stage H40.40x3 Glaucoma secondary to eye inflammation, unspecified eye, severe stage H40.40x4 Glaucoma secondary to eye inflammation, unspecified eye, indeterminate stage H40.41x0 Glaucoma secondary to eye inflammation, right eye, stage unspecified H40.41x1 Glaucoma secondary to eye inflammation, right eye, mild stage H40.41x2 Glaucoma secondary to eye inflammation, right eye, moderate stage H40.41x3 Glaucoma secondary to eye inflammation, right eye, severe stage H40.41x4 Glaucoma secondary to eye inflammation, right eye, indeterminate stage H40.42x0 Glaucoma secondary to eye inflammation, left eye, stage unspecified H40.42x1 Glaucoma secondary to eye inflammation, left eye, mild stage H40.42x2 Glaucoma secondary to eye inflammation, left eye, moderate stage H40.42x3 Glaucoma secondary to eye inflammation, left eye, severe stage H40.42x4 Glaucoma secondary to eye inflammation, left eye, indeterminate stage H40.43x0 Glaucoma secondary to eye inflammation, bilateral, stage unspecified H40.43x1 Glaucoma secondary to eye inflammation, bilateral, mild stage H40.43x2 Glaucoma secondary to eye inflammation, bilateral, moderate stage H40.43x3 Glaucoma secondary to eye inflammation, bilateral, severe stage H40.43x4 Glaucoma secondary to eye inflammation, bilateral, indeterminate stage H40.50x0 Glaucoma secondary to other eye disorders, unspecified eye, stage unspecified H40.50x1 Glaucoma secondary to other eye disorders, unspecified eye, mild stage H40.50x2 Glaucoma secondary to other eye disorders, unspecified eye, moderate stage

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H40.50x3 Glaucoma secondary to other eye disorders, unspecified eye, severe stage H40.50x4 Glaucoma secondary to other eye disorders, unspecified eye, indeterminate stage H40.51x0 Glaucoma secondary to other eye disorders, right eye, stage unspecified H40.51x1 Glaucoma secondary to other eye disorders, right eye, mild stage H40.51x2 Glaucoma secondary to other eye disorders, right eye, moderate stage H40.51x3 Glaucoma secondary to other eye disorders, right eye, severe stage H40.51x4 Glaucoma secondary to other eye disorders, right eye, indeterminate stage H40.52x0 Glaucoma secondary to other eye disorders, left eye, stage unspecified H40.52x1 Glaucoma secondary to other eye disorders, left eye, mild stage H40.52x2 Glaucoma secondary to other eye disorders, left eye, moderate stage H40.52x3 Glaucoma secondary to other eye disorders, left eye, severe stage H40.52x4 Glaucoma secondary to other eye disorders, left eye, indeterminate stage H40.53x0 Glaucoma secondary to other eye disorders, bilateral, stage unspecified H40.53x1 Glaucoma secondary to other eye disorders, bilateral, mild stage H40.53x2 Glaucoma secondary to other eye disorders, bilateral, moderate stage H40.53x3 Glaucoma secondary to other eye disorders, bilateral, severe stage H40.53x4 Glaucoma secondary to other eye disorders, bilateral, indeterminate stage H40.60x0 Glaucoma secondary to drugs, unspecified eye, stage unspecified H40.60x1 Glaucoma secondary to drugs, unspecified eye, mild stage H40.60x2 Glaucoma secondary to drugs, unspecified eye, moderate stage H40.60x3 Glaucoma secondary to drugs, unspecified eye, severe stage H40.60x4 Glaucoma secondary to drugs, unspecified eye, indeterminate stage H40.61x0 Glaucoma secondary to drugs, right eye, stage unspecified H40.61x1 Glaucoma secondary to drugs, right eye, mild stage H40.61x2 Glaucoma secondary to drugs, right eye, moderate stage H40.61x3 Glaucoma secondary to drugs, right eye, severe stage H40.61x4 Glaucoma secondary to drugs, right eye, indeterminate stage H40.62x0 Glaucoma secondary to drugs, left eye, stage unspecified H40.62x1 Glaucoma secondary to drugs, left eye, mild stage H40.62x2 Glaucoma secondary to drugs, left eye, moderate stage H40.62x3 Glaucoma secondary to drugs, left eye, severe stage H40.62x4 Glaucoma secondary to drugs, left eye, indeterminate stage H40.63x0 Glaucoma secondary to drugs, bilateral, stage unspecified H40.63x1 Glaucoma secondary to drugs, bilateral, mild stage H40.63x2 Glaucoma secondary to drugs, bilateral, moderate stage H40.63x3 Glaucoma secondary to drugs, bilateral, severe stage H40.63x4 Glaucoma secondary to drugs, bilateral, indeterminate stage H40.811 Glaucoma with increased episcleral venous pressure, right eye H40.812 Glaucoma with increased episcleral venous pressure, left eye H40.813 Glaucoma with increased episcleral venous pressure, bilateral H40.819 Glaucoma with increased episcleral venous pressure, unspecified eye H40.821 Hypersecretion glaucoma, right eye H40.822 Hypersecretion glaucoma, left eye H40.823 Hypersecretion glaucoma, bilateral H40.829 Hypersecretion glaucoma, unspecified eye H40.831 Aqueous misdirection, right eye H40.832 Aqueous misdirection, left eye H40.833 Aqueous misdirection, bilateral H40.839 Aqueous misdirection, unspecified eye H40.841 Neovascular secondary angle closure glaucoma, right eye H40.842 Neovascular secondary angle closure glaucoma, left eye

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H40.843 Neovascular secondary angle closure glaucoma, bilateral H40.849 Neovascular secondary angle closure glaucoma, unspecified eye H40.89 Other specified glaucoma H40.9 Unspecified glaucoma H42 Glaucoma in diseases classified elsewhere Q15.0 Congenital glaucoma

The following CPT code is considered investigational for Commercial Members: Managed Care (HMO and POS), PPO, Indemnity, Medicare HMO Blue and Medicare PPO Blue:

CPT Codes CPT
codes:

Code Description 0474T Insertion of anterior segment aqueous drainage device, with creation of intraocular reservoir, internal approach, into the supraciliary space

The following CPT codes are considered investigational for Medicare HMO Blue and Medicare PPO Blue:

CPT Codes CPT
codes:

Code Description 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)

Description Glaucoma Glaucoma is the leading cause of irreversible blindness worldwide and is characterized by elevated intraocular pressure (IOP). In 2020, glaucoma affected approximately 52.7 million individuals globally, with a projected increase to 79.8 million in 2040.1, Glaucoma has been reported to be 7 times more likely to cause blindness and 15 times more likely to cause visual impairment in Black individuals as compared to White individuals. In the U.S. in 2010, Black individuals had the highest prevalence rate of primary open angle glaucoma at 3.4% compared to 1.7% among White individuals.

In the primary (conventional) outflow pathway from the eye, aqueous humor passes through the trabecular meshwork, enters a space lined with endothelial cells (Schlemm canal), drains into collector channels, and then into the aqueous veins. Increases in resistance in the trabecular meshwork and/or the inner wall of the Schlemm canal can disrupt the balance of aqueous humor inflow and outflow, resulting in an increase in IOP and glaucoma risk.

Treatment Ocular Medication First-line treatment typically involves pharmacologic therapy. Topical medications either increase the aqueous outflow (prostaglandins, alpha-adrenergic agonists, cholinergic agonists, Rho-kinase inhibitors) or decrease aqueous production (alpha-adrenergic agonists, beta-blockers, carbonic anhydrase inhibitors). Pharmacologic therapy may involve multiple medications, have potential side effects, and may be inconvenient for older adults or incapacitated patients.

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Surgery Surgical intervention may be indicated in patients with glaucoma when the target IOP cannot be reached pharmacologically. Surgical procedures for glaucoma aim to reduce IOP from impaired aqueous humor drainage in the trabecular meshwork and/or Schlemm canal. Trabeculectomy (guarded filtration surgery) is the most established surgical procedure for glaucoma, which involves dissecting the conjunctiva, creating a scleral flap and scleral ostomy, then suturing down the flap and closing the conjunctiva, allowing aqueous humor to directly enter the subconjunctival space. This procedure creates a subconjunctival reservoir, which can effectively reduce IOP, but commonly results in filtering “blebs” on the eye, and is associated with numerous complications (eg, hemorrhage, scarring, hypotony, infection, leaks, bleb-related endophthalmitis) and long-term failure. Other surgical procedures (not addressed herein) include trabecular laser ablation, deep sclerectomy (which removes the outer wall of the Schlemm canal and excises deep sclera and peripheral cornea), and viscocanalostomy (which unroofs and dilates the Schlemm canal without penetrating the trabecular meshwork or anterior chamber) (see evidence review 9.03.26). Canaloplasty involves dilation and tension of the Schlemm canal with a suture loop between the inner wall of the canal and the trabecular meshwork. This ab externo procedure uses the iTrack illuminated microcatheter (iScience Interventional) to access and dilate the entire length of the Schlemm canal and to pass the suture loop through the canal.

Insertion of shunts from outside the eye (ab externo) is another surgical option to lower IOP. Examples of ab externo devices cleared by the U.S. Food and Drug Administration (FDA) include the Ahmed, Baerveldt, Molteno, and EX-PRESS mini-shunt, which shunt aqueous humor between the anterior chamber and the suprachoroidal space. These devices differ by explant surface areas, shape, plate thickness, presence or absence of a valve, and details of surgical installation. Generally, the risk of hypotony (low pressure) is reduced with aqueous shunts compared with trabeculectomy, but IOP outcomes are worse than after standard guarded filtration surgery. The risk of postoperative infection is lower with shunts than with trabeculectomy, and failure rates are similar (»10% of devices fail annually). The primary indication for aqueous shunts is for failed medical or surgical therapy, although some ophthalmologists have advocated their use as a primary surgical intervention, particularly for selected conditions such as congenital glaucoma, trauma, chemical burn, or pemphigoid.

Minimally Invasive Glaucoma Surgeries Minimally invasive glaucoma surgeries (MIGS) are alternative, less invasive techniques that are being developed and evaluated. MIGS, which use microscopic-sized equipment and smaller incisions, involve less surgical manipulation of the sclera and the conjunctiva compared with other surgical techniques. There are several categories of MIGS: miniaturized trabeculectomy, trabecular bypass, milder laser photocoagulation, and totally internal or suprachoroidal stents. Shunts and stents can be administered through an external flap of the conjunctiva and sclera (ab externo) or in a small incision in the cornea with the devices inserted through the anterior chamber of the eye (ab interno). Some ab interno microstents may be inserted with injectors.

Examples of ab interno devices either approved or given marketing clearance by the FDA include the iStent, which is a 1-mm long stent inserted into the end of the Schlemm canal through the cornea and anterior chamber, iStent inject, iStent infinite, and XEN gelatin stent.

Because aqueous humor outflow is pressure-dependent, the pressure in the reservoir and venous system is critical for reaching the target IOP. Therefore, some devices may be unable to reduce IOP below the pressure of the distal outflow system used (eg, <15 mm Hg) and are not indicated for patients for whom very low IOP is desired (eg, those with advanced glaucoma). It has been proposed that stents such as the iStent, iStent inject, and Hydrus Microstent may be useful in patients with early-stage glaucoma to reduce the burden of medications and problems with compliance. One area of investigation is patients with glaucoma who require cataract surgery. An advantage of ab interno stents is that they may be inserted into the same incision and at the same time as cataract surgery. Also, most devices do not preclude subsequent trabeculectomy if needed. It is possible to insert more than 1 stent to achieve desired IOP.

Summary Description

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Glaucoma surgery is intended to reduce intraocular pressure (IOP) when the target IOP cannot be reached using medications. Due to complications with established surgical approaches (eg, trabeculectomy), a variety of shunts and stents are being evaluated as alternative surgical treatments for individuals with inadequately controlled glaucoma. Microstents are also being evaluated in patients with mild-to-moderate open-angle glaucoma (OAG) currently treated with ocular hypotensive medication.

Summary of Evidence For individuals who have refractory OAG who receive ab externo aqueous shunts, the evidence includes RCTs, retrospective studies, and systematic reviews. Relevant outcomes are a change in disease status, functional outcomes, medication use, and treatment-related morbidity. Randomized controlled trials assessing FDA-approved shunts have shown that the use of large externally placed shunts reduces IOP to slightly less than standard filtering surgery (trabeculectomy). Reported shunt success rates show that these devices are noninferior to trabeculectomy in the long term. The FDA-approved shunts have different adverse event profiles and avoid some of the most problematic complications of trabeculectomy. Two trials have compared the Ahmed and Baerveldt shunts. Both found that eyes treated with the Baerveldt shunt had slightly lower average IOP at 5 years than eyes treated with the Ahmed but the Baerveldt also had a higher rate of serious hypotony-related complications. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have refractory OAG who receive ab interno aqueous stents, the evidence includes systematic reviews, an RCT, nonrandomized comparative studies, and a single-arm study. Relevant outcomes are a change in disease status, functional outcomes, medication use, and treatment-related morbidity. The RCT found XEN45 to be noninferior to trabeculectomy. The nonrandomized comparative studies reported that patients receiving the stent experienced similar reductions in IOP and medication use as patients undergoing trabeculectomy. The single-arm study, with 12-month follow-up results, consistently showed that patients receiving the stents experienced reductions in IOP and medication use. In addition, the FDA has given clearance to a gel stent based on equivalent IOP and medication use reductions as seen with ab externo shunts. Clearance for the stent was based on a review in which the FDA concluded that while there were technical differences between the stent and predicate devices (shunts), the differences did not affect safety and effectiveness in lowering IOP and medication use. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have mild-to-moderate OAG who are undergoing cataract surgery who receive aqueous microstents, the evidence includes RCTs and meta-analyses of RCTs. Relevant outcomes are a change in disease status, functional outcomes, medication use, and treatment-related morbidity. Implantation of 1 or 2 microstents has received FDA approval for use in conjunction with cataract surgery for reduction of IOP in adults with mild-to-moderate OAG currently treated with ocular hypotensive medication. When compared to cataract surgery alone, the studies showed modest but statistically significant decreases in IOP and medication use through the first 2 years when stents were implanted in conjunction with cataract surgery. A decrease in topical medication application is considered to be an important outcome for patients and reduces the problem of non-compliance that can affect visual outcomes. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

For individuals with mild-to-moderate OAG who are not undergoing cataract surgery who receive aqueous microstents as a stand-alone procedure, the evidence includes a nonrandomized trial, RCTs and a systematic review of 3 heterogeneous RCTs. Relevant outcomes are a change in disease status, functional outcomes, medication use, and treatment-related morbidity. Several RCTs have evaluated the use of multiple microstents but comparators differed. Two RCTs indicate that implantation of a microstent can reduce IOP at a level similar to ocular medications at 12-month follow-up. Reduction in medications is an important outcome for patients with glaucoma. Whether microstents remain patent after 12 months is uncertain, and whether additional stents can subsequently be safely implanted is unknown. Some evidence on longer-term outcomes is provided by an RCT that compared implantation of a single iStent to implantation of multiple iStents. At longer-term (42-month) follow-up, the need for additional medication increased in eyes implanted with a single microstent but not with multiple microstents. The durability of multiple iStents is unknown. A fourth RCT compared implantation of the Hydrus microstent to 2 iStents. Outcomes from the Hydrus microstent were significantly better than 2 iStents, both statistically and

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clinically, for all outcome measures. The primary limitation of this study is that the duration of follow-up in the publication is limited to 12 months. Longer-term follow-up from this study is continuing and will answer important questions on the durability of the procedure. Corroboration in an independent study and comparison with a medical therapy control group would also increase confidence in the results. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

Policy History Date Action 1/2026 Annual policy review. Policy updated with literature review through September 11, 2025; reference added. Policy statements unchanged. 10/2025 Clarified coding information. 1/2025 Annual policy review. Policy updated with literature review through September 25, 2024; references added. Policy statements unchanged. 11/2023 Annual policy review. Policy updated with literature review through July 27, 2023; references added. Policy statements unchanged. 11/2022 Annual policy review. Description, summary, and references updated. Minor editorial refinements to policy statements; intent unchanged. 1/2022 Clarified coding information. 10/2021 Annual policy review. Description, summary, and references updated. Policy statements unchanged. 1/2021 Medicare information removed. See MP #132 Medicare Advantage Management for local coverage determination and national coverage determination reference.
11/2020 Annual policy review. Description, summary, and references updated. Policy statements unchanged. 10/2019 Annual policy review. Description, summary, and references updated. Policy statements unchanged. 5/2019 Annual policy review. New medically necessary indications described. The use of FDA-approved stent in a stand-alone procedure to reduce IOP pressure is medically necessary. Policy edited to clarify the differences between ab externo shunts and ab interno stents. Clarified coding information. References updated. Effective 5/1/2019. 7/2018 Annual policy review. Policy statements clarified, 2 separate policy statements, one for ab externo devices and one for ab interno devices. 1/2018 Annual policy review. The term “aqueous shunts” modified with “ab externo” and “ab interno” in the Background section.
7/2017 Clarified coding information. 5/2017 Annual policy review. Description, summary, and references updated. Policy statements unchanged. 10/2016 Annual policy review. Summary statements revised to change “quantitatively” to “qualitatively.” Coding information clarified. 4/2016 Annual policy review. New references added. 11/2015 Annual policy review. New references added. 1/2015 Clarified coding information. 5/2014 Updated Coding section with ICD10 procedure and diagnosis codes. Effective 10/2015. 3/2014 Annual policy review. New medically necessary indications described. Effective 3/1/2014. 1/2014 Updated to add new CPT code 66183 and remove deleted code 0192T. 11/2013 Added CPT code 66180 as it meets the intent of the policy. 6/2013 Annual policy review. New investigational indications described. Effective 6/1/2013. 11/2011- 4/2012 Medical policy ICD 10 remediation: Formatting, editing and coding updates. No changes to policy statements.
3/2011 Updated to add new CPT Code 66175.

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2/2011 Reviewed - Medical Policy Group – Psychiatry and Ophthalmology. No changes to policy statements. 8/1/2010 Medical Policy #223 effective 8/1/2010 created.

Information Pertaining to All Blue Cross Blue Shield Medical Policies Click on any of the following terms to access the relevant information: Medical Policy Terms of Use Managed Care Guidelines Indemnity/PPO Guidelines Clinical Exception Process Medical Technology Assessment Guidelines

References

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58. Fellman RL, Mattox C, Singh K, et al. American Glaucoma Society Position Paper: Microinvasive Glaucoma Surgery. Ophthalmol Glaucoma. 2020; 3(1): 1-6. PMID 32672638
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