BlueCross BlueShield of Tennessee Medical Policy Manual

Aqueous Shunts and Stents for Glaucoma

DESCRIPTION

Aqueous shunts and stents for the treatment of glaucoma create an alternative path for aqueous humor to leave the anterior chamber of the eye and thus lower the intraocular pressure (IOP).  They are intended for use in individuals with inadequately controlled glaucoma and for anyone at risk for trabeculectomy failure.

Glaucoma is the second most common cause of blindness worldwide.  It is a progressive optic neuropathy characterized by nerve atrophy and loss of retina ganglion cells.  Signs of disease include an elevated intraocular pressure and loss of peripheral vision.  Pharmacological treatment in the form of eye drops is first-line therapy followed by laser therapy (trabeculoplasty) when drugs fail.

Surgery is considered for individuals who are inadequately controlled or intolerant of medical and laser therapy.  The standard surgical procedure is trabeculectomy, also known as filtering surgery, in which part of the sclera is removed to allow aqueous humor to drain in a controlled manner from the anterior chamber into the sub-conjunctival space.  The surgery may fail over time due to excessive healing (scar formation) at the drainage site, which increases resistance to the outflow of aqueous humor.  Due to the potential complications, a variety of devices, including aqueous shunts and micro-stents are being evaluated.

Use of micro-stents has been studied in individuals with both cataracts and mild to moderate open-angle glaucoma where the IOP is at least partially controlled with medication.  Results of these studies indicate that IOP may be lowered below baseline with decreased need for medication.

Examples of aqueous shunts and stents and FDA status include the following:

Device Manufacturer Type FDA Status Date

Ahmed™

New World Medical Aqueous glaucoma shunt 510(k) < 1993
AquaFlow™ Staar Surgical Drainage device Pre-Market Approval 2001
Baerveldt® Advanced Medical Optics Aqueous glaucoma shunt 510(k) < 1993
Krupin Eagle Vision Aqueous glaucoma shunt 510(k) < 1993
Molteno® Molteno Ophthalmic Aqueous glaucoma shunt 510(k) < 1993
Ex-PRESS® Optonol Aqueous glaucoma shunt 510(k) 2003
iStent® Glaukos Micro-stent Pre-Market Approval 2012
Hydrus™ Ivantis Micro-stent Not Approved  
iStent inject® Glaukos Suprachoroidal stent Not Approved  
iStent supra® Glaukos Suprachoroidal stent Not Approved  
CyPass Transcend Medical Suprachoroidal stent Pre-Market Approval 2016
XEN Gel Stent Allergan, Inc. Subconjunctival 510(k) 2016

POLICY

MEDICAL APPROPRIATENESS

IMPORTANT REMINDERS

ADDITIONAL INFORMATION 

Well-designed studies with long-term outcomes are not available that address the use of aqueous shunts and stents for indications other than those listed above.

SOURCES 

American Academy of Ophthalmology. (2015). Primary open-angle glaucoma. Retrieved March 27, 2017 from the American Academy of Ophthalmology.

Arriola-Villalobos, P., Martinez-de-la-Casa, J. M., Diaz-Valle, D., Fernández-Pérez, C., García-Sánchez, J., & García-Feijoó, J. (2012). Combined iStent trabecular micro-bypass stent implantation and phacoemulsification for coexistent open-angle glaucoma and cataract: A long-term study. British Journal Ophthalmology, 96 (5); 645-649. (Level 3 evidence)

BlueCross BlueShield Association. Medical Policy Reference Manual. (3:2017). Aqueous shunts and stents for glaucoma (9.03.21). Retrieved March 27, 2017 from BlueWeb. (33 articles and/or guideline reviewed)

California Technology Assessment Forum. (2011, June). Aqueous shunts for the treatment of glaucoma. Retrieved July 15, 2015 from http://ctaf.org/reports/aqueous-shunts-treatment-glaucoma (100 articles and /or guidelines reviewed)

Chen, G., Li, W., Jiang, F., May, S., & Tong, Y. (2014). Ex-PRESS implantation versus trabeculectomy in open-angle glaucoma: a meta-analysis of randomized controlled clinical trials. PLoS One, 9 (1). Abstract retrieved July 15, 2015 from PubMed database.

Christakis, P. G., Kalenak, J. W., Tsai, J. C., Zurakowski, D., Kammer, J. A., Harasymowycz, P. J., et al. (2016). The Ahmed versus Baerveldt study: Five-year treatment outcomes. Ophthalmology, 123 (10), 2093-2102. Abstract retrieved March 27, 2017 from PubMed database.

Craven, E. R, Katz, L. J., Wells, J. M., & Giamporcaro, J. E. (2012). Cataract surgery with trabecular micro-bypass stent implantation in patients with mild-to-moderate open-angle glaucoma and cataract: Two-year follow-up. Journal of Cataract & Refractive Surgery, 38 (8), 1339-1345. (Level 2 evidence - Industry sponsored)

de Jong, L. A. (2009). The Ex-PRESS glaucoma shunt versus trabeculectomy in open-angle glaucoma: A prospective randomized study. Advances in Therapy, 26 (3), 336-345. Abstract retrieved July 9, 2012 from PubMed database. (Level 2 evidence)

ECRI Institute. Emerging Technology Evidence Report. (2013, March). Trabecular micro-bypass stent (iStent) for treating open-angle glaucoma. Retrieved July 15, 2015 from ECRI Institute. (50 articles and/or guideline reviewed)

Fea, A. M. (2010). Phacoemulsification versus phacoemulsification with micro-bypass stent implantation in primary open-angle glaucoma: Randomized double-masked clinical trial. Journal of Cataract & Refractive Surgery, 36 (3), 407-412. (Level 2 evidence)

Gedde, S. J., Singh, K., Schiffman, J. C., & Feuer, W. J. (2012). The tube versus trabeculectomy study: interpretation of results and application to clinical practice. Current Opinion in Ophthalmology, 23 (2), 118-126. Abstract retrieved March 27, 2017 from PubMed database.

National Institute for Health and Clinical Evidence (NICE). (2017, February). Trabecular stent bypass microsurgery for open-angle glaucoma. Retrieved March 27, 2017 from http://www.nice.org.uk.

Samuelson, T. W., Katz, L. J., Wells, J. M., Duh, Y., & Giamporcaro, J. E. (2011). Randomized evaluation of the trabecular micro-bypass stent with phacoemulsification in patients with glaucoma and cataract. Ophthalmology, 118 (3), 459-467. (Level 2 evidence - Industry sponsored)

U. S. Food and Drug Administration. (1993, November). Center for Devices and Radiological Health. 510K Database. K925636. Retrieved June 10, 2016 fromhttp://www.accessdata.fda.gov.

U. S. Food and Drug Administration. (2008, May). Center for Devices and Radiological Health. 510K Database. K063583. Retrieved June 10, 2016 from http://www.accessdata.fda.gov.

U. S. Food and Drug Administration. (2012, June). Center for Devices and Radiological Health. Premarket Approval Database. P080030. Retrieved December 4, 2012 from http://www.accessdata.fda.gov.

U. S. Food and Drug Administration. (2016, November). Center for Devices and Radiological Health. Premarket Approval Database. P150037. Retrieved March 28, 2017 from https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpma/pma.cfm?id=P150037S003

Wang, S., Gao, X., & Qian, N. (2016). The Ahmed shunt versus the Baerveldt shunt for refractory glaucoma: a meta-analysis. BMC Ophthalmology, 16 (83). Abstract retrieved March 27, 2017 from PubMed database.

ORIGINAL EFFECTIVE DATE:  12/8/2012

MOST RECENT REVIEW DATE:  7/21/2017

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