Asset Publisher


print Print Back Back

Transciliary Fistulization for the Treatment of Glaucoma

Policy Number: MP-255


Latest Review Date: April 2024

Category: Vision                                                    


Transciliary fistulization for the treatment of glaucoma is considered investigational.


Glaucoma is one of the top causes of blindness in the United States for individuals over age 40. Elevated intraocular pressure is a major contributing factor to developing glaucoma, however, glaucoma might be of multifactorial origin due to a noted relationship between elevated intraocular pressure and optic nerve damage. Glaucoma is characterized by degeneration of the optic disc.

Treatment of glaucoma aims to reduce elevated intraocular pressure, either by administering ocular medications or by using surgical procedures. The goal of ocular medications is to slow aqueous-fluid production. The goal of surgical procedures is to directly drain aqueous humor from the eye or increase the rate of fluid circulation

Topic medication (eye drops) is usually the first therapeutic option. These medications may aid in increasing the outflow of fluid inside the eye, or help limit aqueous humor production while improving fluid outflow. If 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 (trabeculectomy or drainage implants), and as a last resort, ablation of the ciliary body. Incisional or filtering surgery using transciliary fistualization is discussed in this evidence review

Transciliary fistulization is a glaucoma filtering procedure in which a specialized thermocauterization device (Fugo Blade) is used to create a filter track from the sclera through the ciliary body to allow aqueous fluid to drain into subconjunctival lymphatics from 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 because plasma ablation with the Fugo Blade allows the highly vascular ciliary body to be penetrated with little or no bleeding. Aqueous fluid is filtered from the posterior chamber of the eye, in contrast to conventional filtering surgeries that filter from the anterior chamber of the eye.


This policy has been regularly updated with literature reviews. The most recent literature update was performed through April 15, 2024.

Summary of Evidence

Little evidence on this procedure has been identified. 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. 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. Another study that was identified is limited by the absence of a concurrent control, lack of detail in the reporting, and the loss to follow-up. Further studies with longer term follow-up are needed.

No randomized controlled trials were identified on transciliary fistulization for the treatment of glaucoma. This technology should be compared to the current standard of care (trabeculectomy) in well-designed clinical trials. 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.”

No evidence-based guidelines were identified that recommend the use of transciliary fistulization for the treatment of glaucoma.


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


The Fugo Blade (Medisurg, Ltd) for glaucoma was granted U.S. Food and Drug Administration 510(k) marketing clearance in 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: 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-2021.
  3. Dow CT and deVenecia G.  Transciliary filtration (Singh filtration) with the Fugo plasma blade.  Ann Ophthalmol (Skokie), Spring 2008; 40(1): 8-14.
  4. Francis BA et al. Novel glaucoma procedures: A report by the American Academy of Ophthalmology. Ophthalmology 2011 July; 118(7):1466-80.
  5. IOM (Institute of Medicine). 2011. Clinical Practice Guidelines We Can Trust. Washington, DC: The National Academies Press.
  6. Lavia C, Dallorto L, et al. Minimally-invasive glaucoma surgeries (MIGS) for open angle glaucoma: A systematic review and meta-analysis. PloS one. 2017; 12(8):e0183142.
  7. Singh D and Singh K.  Transciliary filtration using the Fugo Blade.  Ann Ophthalmol 2002; 34(3): 183-187.
  8. Sinha R, Bali SJ, Kumar C, et al. Results of cataract surgery and plasma ablation posterior capsulotomy in anterior persistent hyperplastic primary vitreous. Middle East African journal of ophthalmology. 2013; 20(3):217-20.


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. Reviewed by consensus. No new published peer-reviewed literature available that would alter the coverage statement in this policy

Medical Policy Group, March 2022 (9): Updates to Description, Key Points. Reviewed by consensus. References added. No new published peer-reviewed literature available that would alter the coverage statement in this policy.

Medical Policy Group, March 2023 (9): Updates to Key Points and Benefit Application. Reviewed by consensus. No new published peer-reviewed literature available that would alter the coverage statement in this policy.

Medical Policy Group, April 2024 (9): Reviewed by consensus. No new published peer-reviewed literature available that would alter the coverage statement in this policy.


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.