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Transciliary Fistulization for the Treatment of Glaucoma

Policy Number: MP-255

Latest Review Date: March 2021

Category: Ophthalmology                                                     

Policy Grade: Retired effective June 14, 2011. Active Policy but no longer scheduled for regular literature reviews and updates.


Transciliary fistulization for the treatment of glaucoma is considered investigational.


Glaucoma is the second-leading cause of blindness in the United States and is the most prominent in individuals over age 40. Individuals with family history of glaucoma, over the age of 40, thinner corneas, chronic eye inflammation, or taking medications that increase ocular pressure (IOP) have an increased risk to develop glaucoma.

Treatment of glaucoma aims to reduce the patient’s elevated IOP, either by administering ocular medications to slow aqueous-fluid production or by using surgical procedures to directly drain aqueous humor from the eye or increase the rate of fluid circulation. Medication is usually the first therapeutic option. Topical medications (eye drops) containing prostaglandins, for instance, are a typical first option for treating open-angle glaucoma and may aid in increasing the outflow of fluid inside the eye. Other medications such as beta blockers can limit aqueous humor production besides improving fluid outflow. When the maximum tolerated medical therapy fails to control optic neuropathy, surgical care is considered the next treatment option. Surgical procedures include laser trabeculoplasty, incisional or filtering surgery, such as trabeculectomy or drainage implants, and as a last resort, ablation of the ciliary body.

Transciliary fistulization is a glaucoma filtering procedure in which a Fugo Blade, a specialized laser (thermocauterization) device, is used to create a small opening in the sclera under the conjunctival flap. Through this opening, excess fluid can drain into the eye’s posterior chamber (behind the iris), where it is slowly absorbed by the body. The IOP of the eye is decreased as a result. This technique differs from conventional filtering surgeries in which aqueous fluid is filtered from the anterior chamber of the eye. Transciliary fistulization allows aqueous fluid to drain from the posterior chamber of the eye. This procedure results in a rapid reduction in IOP and takes less than 15 minutes to perform.


This policy has been regularly updated with literature reviews. The most recent literature update was performed through March 23, 2021.

Summary of Evidence

One case series study by Singh and Singh of 147 patients treated with transciliary filtration (or fistulization) for the treatment of glaucoma followed up for up to six months has been identified. The authors reported at six months that intraocular pressures were reduced to 21 mm Hg or below without medication in 132 eyes. The decrease in intraocular pressures was statistically significant (p<0.02), and no cases of anterior chamber flattening occurred. Adverse events included the need for surgical revision in seven patients three months after surgery, and choroidal effusion in two patients, which resolved within one month after surgery. No data on changes in vision or optic neuropathy were reported.

Little additional evidence on this procedure has been identified. An additional study identified is limited by the absence of a concurrent control, lack of detail in the reporting, and the loss to follow-up.

The limited literature since 2002 suggests poor acceptance of this procedure by the ophthalmologic community; the reasons for this are not clear. While this procedure is similar to other filtration procedures commonly performed for the surgical treatment of glaucoma, further studies with longer term follow-up are needed. Overall, the data are insufficient to determine the long-term health outcomes of transciliary fistulization for the treatment of glaucoma. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

Practice Guidelines and Position Statements

American Academy of Ophthalmology (AAO)

In 2015, AAO published benchmarks for primary open-angle glaucoma which state: “medical therapy is presently the most common initial intervention to lower IOP. Laser trabeculoplasty can be considered as initial therapy in select patients or an alternative for patients at high risk for non-adherence to medical therapy who cannot or will not use medications reliably.”


Transciliary fistulization, transciliary filtration, fistulization of sclera, glaucoma, increased intraocular pressure, fugo blade, Singh filtration


The Fugo Blade (Medisurg, Ltd) for glaucoma was given FDA 510(k) marketing clearance October 2004 for sclerostomy for the treatment of primary open-angle glaucoma where maximum tolerated medical therapy and trabeculoplasty have failed. 


Coverage is subject to member’s specific benefits.  Group specific policy will supersede this policy when applicable.

ITS: Home Policy provisions apply

FEP contracts: FEP does not consider investigational if FDA approved and will be reviewed for medical necessity. Special benefit consideration may apply.  Refer to member’s benefit plan.


CPT Codes:


Unlisted procedure, anterior segment of eye


  1. American Academy of Ophthalmology. (2005). Preferred practice patterns in primary open-angle glaucoma.
  2. American Academy of Ophthalmology. Primary Open-Angle Glaucoma Summary Benchmarks for Preferred Practice Guidelines (2015 November). Available at: <>
  3. Blue Cross Blue Shield Association.  Transciliary fistulization for the treatment of glaucoma.  Medical Policy Reference Manual, January 2010.
  4. Dow CT and deVenecia G.  Transciliary filtration (Singh filtration) with the Fugo plasma blade.  Ann Ophthalmol (Skokie), Spring 2008; 40(1): 8-14.
  5. Francis BA et al. Novel glaucoma procedures: A report by the American Academy of Ophthalmology. Ophthalmology 2011 July; 118(7):1466-80.
  6. Jacobs, Deborah. Open-Angle Glaucoma: UpToDate Post TW (Ed), UpToDate, Waltham, MA. Topic last updated: December 22, 2015. Available at:
  7. IOM (Institute of Medicine). 2011. Clinical Practice Guidelines We Can Trust. Washington, DC: The National Academies Press.
  8. Singh D and Singh K.  Transciliary filtration using the Fugo Blade.  Ann Ophthalmol 2002; 34(3): 183-7.


Medical Policy Group, October 2005 (2)

Medical Policy Administration Committee, October 2005

Available for comment October 24-December 7, 2005

Medical Policy Group, October 2006 (1) (Literature search (i.e., Pubmed, Medscape) performed with no new information found)

Medical Policy Group, October 2007 (1)

Medical Policy Group, February 2009 (4)

Medical Policy Group, February 2010 (1)

Medical Policy Group, June 14, 2011; Active Policy but no longer scheduled for regular literature reviews and updates.

Medical Policy Group, November 2015: 2016 Annual Coding Update. Created new previous coding section and moved CPT code 0123T under this section. Added unlisted CPT code 66999 to current coding.

Medical Policy Group, November 2019 (6): Updates to Description, Key Points, Key Words (Singh filtration) and References. No change to policy intent.

Medical Policy Group, March 2021 (9): Updates to Description, Key Points, References. Policy statement updated to remove “not medically necessary,” no change to policy intent.

This medical policy is not an authorization, certification, explanation of benefits, or a contract. Eligibility and benefits are determined on a case-by-case basis according to the terms of the member’s plan in effect as of the date services are rendered. All medical policies are based on (i) research of current medical literature and (ii) review of common medical practices in the treatment and diagnosis of disease as of the date hereof. Physicians and other providers are solely responsible for all aspects of medical care and treatment, including the type, quality, and levels of care and treatment.

This policy is intended to be used for adjudication of claims (including pre-admission certification, pre-determinations, and pre-procedure review) in Blue Cross and Blue Shield’s administration of plan contracts.

The plan does not approve or deny procedures, services, testing, or equipment for our members. Our decisions concern coverage only. The decision of whether or not to have a certain test, treatment or procedure is one made between the physician and his/her patient. The plan administers benefits based on the member’s contract and corporate medical policies. Physicians should always exercise their best medical judgment in providing the care they feel is most appropriate for their patients. Needed care should not be delayed or refused because of a coverage determination.

As a general rule, benefits are payable under health plans only in cases of medical necessity and only if services or supplies are not investigational, provided the customer group contracts have such coverage.

The following Association Technology Evaluation Criteria must be met for a service/supply to be considered for coverage:

1. The technology must have final approval from the appropriate government regulatory bodies;

2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes;

3. The technology must improve the net health outcome;

4. The technology must be as beneficial as any established alternatives;

5. The improvement must be attainable outside the investigational setting.

Medical Necessity means that health care services (e.g., procedures, treatments, supplies, devices, equipment, facilities or drugs) that a physician, exercising prudent clinical judgment, would provide to a patient for the purpose of preventing, evaluating, diagnosing or treating an illness, injury or disease or its symptoms, and that are:

1. In accordance with generally accepted standards of medical practice; and

2. Clinically appropriate in terms of type, frequency, extent, site and duration and considered effective for the patient’s illness, injury or disease; and

3. Not primarily for the convenience of the patient, physician or other health care provider; and

4. Not more costly than an alternative service or sequence of services at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of that patient’s illness, injury or disease.