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Official Description

Fistulization of sclera for glaucoma; trephination with iridectomy

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The procedure described by CPT® Code 66150 involves the surgical technique known as fistulization of the sclera, specifically aimed at treating glaucoma. This procedure utilizes trephination combined with an iridectomy. In simpler terms, scleral fistulization is a method employed to create a new pathway for fluid drainage within the eye, which is crucial for managing intraocular pressure associated with glaucoma. During the operation, the eye is examined under an operating microscope to ensure precision and clarity. An incision is made in the conjunctiva, which is the thin membrane covering the white part of the eye, located near the limbus—the border between the cornea and sclera. This incision allows the surgeon to access the sclera, the tough outer layer of the eye. A flap is then created in the sclera, and a specialized surgical instrument known as a trephine is utilized to excise a small disc of tissue from the iris. This excision, referred to as an iridectomy, facilitates the flow of aqueous humor between the anterior and posterior chambers of the eye, effectively lowering the intraocular pressure. After the necessary modifications are made, the scleral incision is meticulously closed with sutures, followed by the closure of the conjunctiva to complete the procedure.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The procedure described by CPT® Code 66150 is indicated for the treatment of glaucoma, particularly in cases where intraocular pressure needs to be reduced to prevent damage to the optic nerve. The following conditions may warrant the performance of this procedure:

  • Glaucoma A condition characterized by increased intraocular pressure that can lead to optic nerve damage and vision loss.
  • Inadequate response to medical therapy Situations where patients do not achieve sufficient pressure control with medications alone.
  • Progressive optic nerve damage Instances where there is evidence of ongoing damage to the optic nerve despite treatment.

2. Procedure

The procedure for CPT® Code 66150 involves several critical steps to ensure effective treatment of glaucoma:

  • Step 1: Preparation and Anesthesia The patient is positioned comfortably, and local anesthesia is administered to minimize discomfort during the procedure. The eye is then prepared and draped in a sterile manner to maintain a clean surgical field.
  • Step 2: Conjunctival Incision An incision is made in the conjunctiva, which is the membrane covering the eye, located near the limbus. This incision allows access to the underlying sclera, the white part of the eye.
  • Step 3: Scleral Flap Creation A flap is created in the sclera to facilitate the next steps of the procedure. This flap is essential for accessing the inner structures of the eye.
  • Step 4: Trephination A trephine, a specialized surgical instrument, is used to remove a small disc of tissue from the iris. This step is crucial as it creates an opening in the iris, known as an iridectomy, which allows for improved fluid drainage.
  • Step 5: Closure of Scleral Incision After the iridectomy is performed, the scleral incision is carefully closed with sutures to ensure proper healing and to maintain the integrity of the eye.
  • Step 6: Closure of Conjunctiva Finally, the conjunctiva is closed over the scleral flap, completing the procedure and ensuring that the surgical site is protected.

3. Post-Procedure

After the completion of the procedure, patients are typically monitored for any immediate complications. Post-operative care may include the use of prescribed medications, such as anti-inflammatory or antibiotic eye drops, to prevent infection and manage inflammation. Patients are advised to follow up with their ophthalmologist to assess the success of the procedure and to monitor intraocular pressure. Recovery time may vary, but patients are generally encouraged to avoid strenuous activities and to adhere to any specific instructions provided by their healthcare provider to ensure optimal healing.

Short Descr GLAUCOMA SURGERY
Medium Descr FSTLJ SCLERA GLAUCOMA TREPHIN W/IRIDECTOMY
Long Descr Fistulization of sclera for glaucoma; trephination with iridectomy
Status Code Active Code
Global Days 090 - Major Surgery
PC/TC Indicator (26, TC) 0 - Physician Service Code
Multiple Procedures (51) 2 - Standard payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50) 1 - 150% payment adjustment for bilateral procedures applies.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 1 - Statutory payment restriction for assistants at surgery applies to this procedure...
Co-Surgeons (62) 1 - Co-surgeons could be paid, though supporting documentation is required...
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family 99 - Concept Does Not Apply
APC Status Indicator Hospital Part B services paid through a comprehensive APC
ASC Payment Indicator Surgical procedure on ASC list in CY 2007; payment based on OPPS relative payment weight.
Type of Service (TOS) 2 - Surgery
Berenson-Eggers TOS (BETOS) P4E - Eye procedure - other
MUE 1
CCS Clinical Classification 14 - Glaucoma procedures
51 Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d).
52 Reduced services: under certain circumstances a service or procedure is partially reduced or eliminated at the discretion of the physician or other qualified health care professional. under these circumstances the service provided can be identified by its usual procedure number and the addition of modifier 52, signifying that the service is reduced. this provides a means of reporting reduced services without disturbing the identification of the basic service. note: for hospital outpatient reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well-being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use).
LT Left side (used to identify procedures performed on the left side of the body)
RT Right side (used to identify procedures performed on the right side of the body)
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