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The CPT® Code 66175 refers to the procedure known as transluminal dilation of the aqueous outflow canal, specifically Schlemm's canal, with the retention of a device or stent. This procedure is primarily indicated for the treatment of open-angle glaucoma, a condition characterized by increased intraocular pressure (IOP) that can lead to optic nerve damage and vision loss. The technique aims to enhance the natural drainage of aqueous humor from the eye, thereby reducing IOP. During the procedure, a scleral flap is created to access the canal, which is then deroofed to expose its interior. A flexible hollow microcatheter with a lighted tip is introduced into the canal, allowing for visualization and navigation. A viscoelastic agent, such as high viscosity sodium hyaluronate, is instilled to facilitate the dilation of the canal. Unlike the related procedure coded as 66174, which does not involve the retention of a device, CPT® Code 66175 includes the placement of a stent or suture within the canal to maintain its patency. This retention is crucial as it helps to keep the canal open, thereby ensuring continued drainage of fluid and management of IOP in patients suffering from glaucoma.
© Copyright 2025 Coding Ahead. All rights reserved.
The procedure coded as CPT® 66175 is indicated for the treatment of open-angle glaucoma, a condition where the drainage of aqueous humor is impaired, leading to increased intraocular pressure (IOP). This procedure is performed to alleviate symptoms associated with elevated IOP and to prevent potential damage to the optic nerve, which can result in vision loss.
The procedure begins with the creation of a scleral flap, which allows access to Schlemm's canal. The surgeon carefully deroofs the canal to expose its interior, facilitating the next steps of the procedure. A flexible hollow microcatheter, equipped with a lighted tip, is then introduced into the canal. The illumination provided by the lighted tip aids in visualizing the canal as the microcatheter is advanced through its length. To assist in the dilation of the canal, a viscoelastic agent, such as high viscosity sodium hyaluronate, is instilled. This agent helps to expand the canal and eases the advancement of the microcatheter. Once the microcatheter has traversed the entire length of the canal, it is withdrawn. At this point, a flexible stent or suture is advanced along the same path as the microcatheter, ensuring that it occupies the full length of the canal. The retention of this device is critical, as it serves to keep the canal open. If a suture is utilized, it is tied off and left in place, cinching and stretching the trabecular meshwork inward to maintain the patency of the canal.
After the completion of the procedure, patients may be monitored for any immediate complications or adverse effects. Post-operative care typically includes the use of anti-inflammatory medications and possibly antibiotics to prevent infection. Patients are advised to follow up with their ophthalmologist to assess the effectiveness of the procedure in lowering IOP and to monitor for any potential complications related to the retained device or stent. The expected recovery period may vary, but patients are generally encouraged to resume normal activities as tolerated, while adhering to any specific post-operative instructions provided by their healthcare provider.
| Short Descr | TRLUML DIL AQ O/F CAN W/ST | Medium Descr | TRLUML DILAT AQUEOUS O/F CAN W/RETENTION DEV/ST | Long Descr | Transluminal dilation of aqueous outflow canal (eg, canaloplasty); with retention of device or stent | 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) | 2 - Payment restriction for assistants at surgery does not apply 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 | Device-intensive procedure added to ASC list in CY 2008 or later; paid at adjusted rate. | Type of Service (TOS) | 2 - Surgery | Berenson-Eggers TOS (BETOS) | P1G - Major procedure - Other | MUE | 1 | CCS Clinical Classification | 14 - Glaucoma procedures |
| RT | Right side (used to identify procedures performed on the right side of the body) | LT | Left side (used to identify procedures performed on the left side of the body) | 79 | Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.) | 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). | 54 | Surgical care only: when 1 physician or other qualified health care professional performs a surgical procedure and another provides preoperative and/or postoperative management, surgical services may be identified by adding modifier 54 to the usual procedure number. | 55 | Postoperative management only: when 1 physician or other qualified health care professional performed the postoperative management and another performed the surgical procedure, the postoperative component may be identified by adding modifier 55 to the usual procedure number. | 58 | Staged or related procedure or service by the same physician or other qualified health care professional during the postoperative period: it may be necessary to indicate that the performance of a procedure or service during the postoperative period was: (a) planned or anticipated (staged); (b) more extensive than the original procedure; or (c) for therapy following a surgical procedure. this circumstance may be reported by adding modifier 58 to the staged or related procedure. note: for treatment of a problem that requires a return to the operating/procedure room (eg, unanticipated clinical condition), see modifier 78. | 59 | Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25. | 82 | Assistant surgeon (when qualified resident surgeon not available): the unavailability of a qualified resident surgeon is a prerequisite for use of modifier 82 appended to the usual procedure code number(s). | GC | This service has been performed in part by a resident under the direction of a teaching physician | SG | Ambulatory surgical center (asc) facility service | XS | Separate structure, a service that is distinct because it was performed on a separate organ/structure |
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| 2023-01-01 | Changed | Code description changed. |
| 2011-01-01 | Added | Added |
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