Revenue Cycle Insider

Find out when you need to turn to Category III codes.

Recently, there have been numerous requests to break down the Who, What, When, Where, and Why of a goniotomy. In this article, Revenue Cycle Insider delves into the guidelines, what codes can and cannot be reported, and how to better discern coding guidelines for this procedure.

Read on to learn more about the glaucoma surgical intervention.

Understand What a Goniotomy Entails

First, we must outline what a goniotomy is. The Coders’ Desk Reference defines the treatment as “A procedure performed when a physician enters the anterior chamber through an incision in the scleral-corneal juncture (limbus) and cuts with a gonioknife.” However, what most coders do not know is there are multiple names for the goniotomy, such as De Vincentis or Barkan’s operation.

According to an August 2022 CPT^® Assistant, “Code 65820 [Goniotomy] requires incision of an ‘extensive’ portion of the trabecular meshwork, often using a goniotomy knife.” The article instructs you not to report 65820 separately if the provider’s incision into the trabecular meshwork is “minimal or incidental to another ophthalmic procedure,” and the code shouldn’t be reported alongside codes describing aqueous drainage device insertion, such as 0449T (Insertion of aqueous drainage device, without extraocular reservoir, internal approach, into the subconjunctival space; initial device) and 66183 (Insertion of anterior segment aqueous drainage device, without extraocular reservoir, external approach).

Furthermore, in the May 2022 CPT^® Assistant, the AMA noted the increase of assigning procedure code 66174 (Transluminal dilation of aqueous outflow canal (eg, canaloplasty); without retention of device or stent) or 66175 (Transluminal dilation of aqueous outflow canal (eg, canaloplasty); with retention of device or stent) along with 65820. After numerous inquiries, the AMA noted the procedure described by 65820 is “considered an inherent component of code 66174.” Therefore, the two codes should not be reported together.

Additionally, the AMA added a parenthetical note to the code set in 2022 following code 66174 to “restrict” reporting 66174 with 65820 to when the procedures are performed in the same session. You should only report 66174, since the procedure includes incising through the trabecular meshwork and would also be incidental to the service performed under 66174.

Report Category III Codes As Needed

Both new and experienced coders may feel confused as to when it is appropriate to assign 65820 — specifically regarding the tools and methods used during the surgical procedure. The August 2022 issue of CPT^® Assistant examined what code to report if the surgeon makes one or multiple punctures in the trabecular meshwork to inject small amounts of viscoelastic materials into the Schlemm’s canal.

In that case, you’ll report 66999 (Unlisted procedure, anterior segment of eye) when the surgeon injects viscoelastic material into a specific area using one to three openings. This is because 65820 requires the provider to use a surgical blade or tool to perform an incision or excision of the eye’s trabecular meshwork.

As if the coding assignment for goniotomy wasn’t complicated enough, the AMA added two new Category III codes in 2022 to report trabeculostomy ab interno by laser for patients with glaucoma, for whom laser trabeculoplasty or medications were unsuccessful treatment options.

The CPT^® Category III codes are:

• 0621T (Trabeculostomy ab interno by laser)
• 0622T (… with use of ophthalmic endoscope)

The AMA received numerous questions regarding the use of 0621T and 0622T when 65820 already existed to report glaucoma surgery. However, the AMA noted in its September 2021 CPT^® Assistant that 65820 did not accurately describe trabeculostomy ab interno by laser. The organization also instructed coders not to report unlisted procedure code 66999 for procedures now described under 0621T and 0622T. Many differences in the procedures and surgery codes were listed citing the differences between goniotomy, trabeculoplasty, and iridotomy/iridectomy and when to assign each of the codes.

For instance, 65820 is a minimally invasive surgical procedure for the treatment of glaucoma. Code 0621T describes an excimer laser trabeculostomy (ELT), which uses a gonio lens to view the anterior chamber angle. The codes differ because 65820’s surgical approach involves the “opening of the trabecular meshwork using a surgical blade or other cutting instrument,” whereas procedure code 0621T utilizes a laser and does not include placement of a stent.

In conclusion, you should be careful assigning procedure codes when the physician performs a goniotomy for glaucoma. Each of the instances for assignment within this article denotes when a physician enters the anterior chamber, limbus, and passes through the trabecular meshwork.

Amy C. Pritchett, MSHA, AAPC Fellow, RAP, CRC, CPA-RA, CCS, CPC, CPMA, CPCO, CDEI, CDEO, CDEC, CANPC, CASCC,CMPM, AAPC Approved Instructor, Approved ICD-10-CM/PCS Trainer, Senior Manager, RHACE, Mobile, Alabama Office