BlueCross BlueShield of Tennessee Medical Policy Manual

Aqueous Shunts and Stents for Glaucoma

DESCRIPTION

Glaucoma is the second most common cause of blindness worldwide. It is a progressive optic neuropathy characterized by nerve atrophy and loss of vision. Signs of disease include an elevated intraocular pressure (IOP) 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 traditional surgical procedure is called a trabeculectomy, in which part of the sclera is removed to allow aqueous humor to drain in a controlled manner. The surgery may fail over time due to scar formation at the drainage site. Due to the potential complications and a relatively high failure rate (approximately 20%), a variety of alternative devices are being developed.

Aqueous shunts inserted from outside the eye (ab externo) drain aqueous humor away from the anterior chamber by a variety of surgical installation details (e.g., canals, filters, valves). The incisional approach cuts through the conjunctiva and sclera.

Miicro-stents have been used in individuals with mild to moderate open-angle glaucoma where optimal IOP has not been achieved with medication. The incisional approach is similar to cataract surgery (ab interno) and may be inserted during cataract surgery or as a stand-alone procedure.

Examples of FDA approved aqueous shunts and stents

POLICY

• Insertion of an aqueous shunt is considered medically necessary if the medical appropriateness criteria are met. (See Medical Appropriateness below.)

• Insertion of an aqueous micro-stent is considered medically necessary if the medical appropriateness criteria are met. (See Medical Appropriateness below.)

• Any aqueous shunt or micro-stent device utilized must have FDA approval specific to the indication, otherwise it will be considered investigational.

MEDICAL APPROPRIATENESS

• Use of aqueous shunts or micro-stents is considered medically appropriate if ALL the following are met:

• Diagnosis of glaucoma

• Device requested is ANY ONE of the following:

• • Aqueous shunt when ocular hypotensive medication(s) have failed to adequately control intraocular pressure

  • Micro-stent as stand-alone procedure when ocular hypotensive medication(s) have failed to adequately control intraocular pressure

  • Micro-stent(s) inserted in conjunction with cataract surgery when ALL the following are met:

  • • Individual is currently being treated with ocular hypotensive medication(s)

    • Either one or two stents placed

IMPORTANT REMINDERS

• Any specific products referenced in this policy are just examples and are intended for illustrative purposes only. It is not intended to be a recommendation of one product over another and is not intended to represent a complete listing of all products available. These examples are contained in the parenthetical e.g., statement.

• We develop Medical Policies to provide guidance to Members and Providers. This Medical Policy relates only to the services or supplies described in it. The existence of a Medical Policy is not an authorization, certification, explanation of benefits or a contract for the service (or supply) that is referenced in the Medical Policy. For a determination of the benefits that a Member is entitled to receive under his or her health plan, the Member's health plan must be reviewed. If there is a conflict between the Medical Policy and a health plan or government program (e.g., TennCare), the express terms of the health plan or government program will govern.

SOURCES  

American Academy of Ophthalmology. (2020). Primary open-angle glaucoma. Retrieved July 13,2021 from https://www.aao.org/.

Ansari, E. (2017). An update on implants for minimally invasive glaucoma surgery (MIGS). Ophthalmology Therapy, (6), 233-241. (Level 2 evidence)

BlueCross BlueShield Association. Evidence Positioning System. (10:2022). Aqueous shunts and stents for glaucoma (9.03.21). Retrieved August 29,2023 from bcbsaoca.co/eps/. (48 articles and/or guideline 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.

CMS.gov: Centers for Medicare & Medicaid Services. Palmetto GBA. (2022, June). Micro-invasive glaucoma surgery (MIGS). (LCD L37531). Retrieved July 28,2022 from https://www.cms.gov.

DeGregorio, A., Pedrotti, E., Stevan, G., Bertoncello, A., & Morselli, S. (2018). XEN gel stent in the management of glaucoma. Clinical Ophthalmology, (12), 773-782. (Level 2 evidence)

Fox, A., Risma, T., & Bettis, D. (2017). MIGS: minimally invasive glaucoma surgery. Retrieved May 17,2018 from https://webeye.ophth.uiowa.edu/eyeforum/tutorials/migs.

Grover, D., Flynn, W., Bashford, K., Lewis, R., Duh, Y., Nangia, R., et al. (2017). Performance and safety of a new ab interno gelatin stent in refractory glaucoma at 12 Months. American Journal of Ophthalmology, (183), 25-36. (Level 3 evidence)

Katz, L., Erb, C., Guillamet, A., Fea, A., Voskanyan, L., Giamporcaro, J., et al. (2018). Long-term titrated IOP control with one, two, or three trabecular micro-bypass stents in open-angle glaucoma subjects on topical hypotensive medication: 42-month outcomes. Clinical Ophthalmology, (12), 255-262. (Level 2 evidence)

Lee, J., Amoozgar, B. & Han, Y. (2017). Minimally invasive modalities for treatment of glaucoma: an update. Journal of Clinical & Experimental Ophthalmology, 8 (4). (Level 2 evidence)

Lim, S.Y., Betzler, B.K., Yip, L.W.L., Dorairaj, S., & Ang, B.C.H. (2022). Standalone xen45 gel stent implantation in the treatment of open-angle glaucoma: A systematic review and meta-analysis. Survey of Ophthalmology, 67 (4), 1048-1061. Abstract retrieved August 30, 2023 from PubMed database.

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

National Institute for Health and Clinical Evidence (NICE). (2018, April). Microinvasive subconjunctival insertion of a trans-scleral gelatin stent for primary open-angle glaucoma. Retrieved August 30,2023 from http://www.nice.org.uk. 

U. S. Food and Drug Administration. (2016, October). Center for Devices and Radiological Health. 510K Notification Database. K161457. (Xen Glaucoma Treatment System). Retrieved May 21,2018 from http://www.accessdata.fda.gov.

U. S. Food and Drug Administration. (1993, November). Center for Devices and Radiological Health. 510K Notification Database. K925636 (Ahmed®). 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 (iStent®). Retrieved December 4,2012 from http://www.accessdata.fda.gov.

U. S. Food and Drug Administration. (2018, August). Center for Devices and Radiological Health. Premarket Approval Database. P170034 (Hydras®). Retrieved December 14,2018 from https://www.accessdata.fda.gov.  

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.

Winifred S. Hayes, Inc. Health Technology Assessment. (2019, September; last update search November 2022). iStent inject trabecular micro-bypass stent (Glaukos Corp.) as a standalone procedure for open-angle glaucoma. Retrieved August 29,2023 from www.hayesinc.com/subscribers. (46 guidelines and/or articles reviewed)

Winifred S. Hayes, Inc. Health Technology Assessment. (2019, December; last update search April 2023). XEN glaucoma treatment system (Allergan) for treatment of open-angle glaucoma. Retrieved August 29,2023 from www.hayesinc.com/subscribers. (57 guidelines and/or articles reviewed)

Yang, X., Zhao, Y., Zhong, Y., & Duan, X. (2022). The efficacy of XEN gel stent implantation in glaucoma: a systematic review and meta-analysis. BMC Ophthalmology, 22 (1), 305. (Level 1 evidence)

Yousef, A., Strzalkowska, A., Hillenkamp, J., Rosentreter, A., & Lowewen, N.A. (2020). Comparison of a second-generation trabecular bypass (istent inject) to ab interno trabeculectomy (Trabectome) by exact matching. Graefes Archive for Clinical and Experimental Opthalmology, 258 (12), 2775-2780. (Level 5 evidence)

ORIGINAL EFFECTIVE DATE:  12/8/2012

MOST RECENT REVIEW DATE:  10/12/2023

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Policies included in the Medical Policy Manual are not intended to certify coverage availability. They are medical determinations about a particular technology, service, drug, etc. While a policy or technology may be medically necessary, it could be excluded in a member's benefit plan. Please check with the appropriate claims department to determine if the service in question is a covered service under a particular benefit plan. Use of the Medical Policy Manual is not intended to replace independent medical judgment for treatment of individuals. The content on this Web site is not intended to be a substitute for professional medical advice in any way. Always seek the advice of your physician or other qualified health care provider if you have questions regarding a medical condition or treatment.

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