STAY ABREAST Glaucoma codes are struggling to keep pace with the rapidly evolving field of glaucoma surgery.

Glaucoma surgery is evolving at such a frenzied pace that CPT and HCPCS codes sometimes struggle to keep up. You might, too, as new codes are introduced and existing codes are amended almost yearly. Let's step back and review how to correctly report glaucoma for maximum reimbursement.

Shunting procedures
The oldest of the codes considered in this subheading, code 66180 Aqueous shunt to extraocular reservoir (e.g., Molteno, Schocket, Denver-Krupin), refers to the placement of a shunt into the anterior chamber that drains aqueous humor to a plate that serves as a reservoir on the posterior segment of the ocular surface. In addition to the devices given as examples in the code descriptor, Ahmed and Baerveldt devices are also commonly implanted during this procedure.

You can report the code for scleral reinforcement (67255) in addition to the code for aqueous shunt implantation when you document this procedure, according to the June 2012 CPT Assistant. The National Correct Coding Initiative (NCCI) has no edit for these procedures and therefore a modifier to unbundle them is not necessary for Medicare; however, the aforementioned CPT Assistant article suggests appending a —59 modifier to code 67255 due to its "separate procedure" designation.

Code L8612 Aqueous shunt is assigned for the aqueous shunt implant. It is packaged into the charge for the main procedure under both the OPPS and ASC payment systems, having an N status indicator and N1 payment indicator respectively, and therefore Medicare makes no additional payment for the implant. Scleral reinforcement grafts such as Tutoplast pericardium graft are reported with code L8610 Ocular implant. However, as with L8612, Medicare makes no additional payment. The supply of amniotic membrane for coverage of the reservoir plate is reported with V2790 which also has an N status indicator and N1 payment indicator, meaning Medicare makes no additional payment.

Revisional surgery to the aqueous shunt is reported through 66185 Revision of aqueous shunt to extraocular reservoir and includes repositioning of the shunt deeper into the anterior chamber in order to prevent corneal decompensation.

There are 3 codes for placement of an aqueous shunt without an attached reservoir plate. These codes were created to keep pace with newer technology in glaucoma surgery. Assignment of these codes depends on the approach and type of device.

• 0191T. Placement within the trabecular meshwork of drainage devices without reservoirs such as the Glaukos iStent Trabecular Micro-Bypass Stent or Ex-Press Mini Glaucoma Shunt is reported with Category III CPT code 0191T Insertion of anterior segment aqueous drainage device, without extraocular reservoir; internal approach, into the trabecular meshwork. This procedure is similar to trabeculectomy with the exception, of course, that the device is placed.

• 0253T. A new code was implemented on January 1, 2011, for the drainage device placed into the suprachoroidal space. 0253T Insertion of anterior segment aqueous drainage device, without extraocular reservoir; internal approach, into the suprachoroidal space was created for devices such as the Glaukos iStent Supra, Transcend Cypass Micro-Stent and Solx Deeplight Gold Micro-Shunt.

• 0192T. Report 0192T Insertion of anterior segment aqueous drainage device, without extraocular reservoir; external approach for a device placed via external approach such as the Aquaflow Collagen Glaucoma Drainage Device and the Ex-Press Glaucoma Filtration Device. Medicare HCPCS code C1783 Ocular implant, aqueous drainage assist device is reported for the device. As is the case with L8612, C1783 is considered packaged into the main procedure under the OPPS and ASC payment systems and is not separately reimbursed by Medicare.

Diagnosis codes from the open angle glaucoma series (365.10-365.15) currently demonstrate medical necessity for code 0192T, according to CMS. Keep up to date with your local Medicare contractor's coverage determinations and check your commercial payer contracts for current coverage requirements. Also encourage your surgeons to make sure they adequately document the indications for the procedure(s).

Under OPPS, the codes for all glaucoma procedures considered above belong to APC 0673, which has a Medicare national payment rate of $2,977.93 for 2013. Because the above-mentioned devices have an N status indicator and are therefore packaged into the main procedure for Medicare, this rate includes reimbursement for the device(s) as well as for the procedure. Code 67255 belongs to APC 0237, which has a Medicare national payment rate of $1,442.12. This rate would include the reinforcement graft(s), which are packaged due to their N status indicator.

For ambulatory surgery centers, the aforementioned glaucoma codes have a Medicare national payment rate of $1,671.00 for 2013. As is the case with OPPS, the device codes for these procedures are packaged into the code for the main procedure by virtue of their N1 payment indicator under the ASC payment system. Therefore, the payment rate for the procedure includes payment for the device(s). Code 67255 has a Medicare national payment rate of $809.22 for ASCs.

2013 Medicare National
Payment Rates for Glaucoma Surgery

Procedure	Hospital Outpatient Rate	ASC Rate
Aqueous shunt	$2,977.93	$1,671.00
Trabeculectomy	$1,676.62	$940.80
Canaloplasty	$2,977.93	$1,671.00

Trabeculectomy
Trabeculectomy is the most common surgical procedure performed for the treatment of glaucoma. For this procedure, typically a scleral flap is created through which a small block of trabecular tissue is excised, creating a fistula through which aqueous can flow out of the anterior chamber. A conjunctival flap is sutured over the scleral flap to form a bleb that acts as a reservoir for the outflowing aqueous.

When this is done in the absence of scarring due to surgery and/or trauma, you should report 66170 Fistulization of sclera for glaucoma; trabeculectomy ab externo in absence of previous surgery. When scarring is present, 66172 Fistulization of sclera for glaucoma; trabeculectomy ab externo with scarring from previous ocular surgery or trauma (includes injection of antifibrotic agents) is the correct code (Source: July 2003 CPT Assistant, "Trabeculectomy: Filtering Surgery for Glaucoma," page 1).

Both trabeculectomy codes belong to APC 0234 and have a Medicare national payment rate of $1,676.62 under OPPS. For the ASC payment system, the procedures both have a Medicare national payment rate of $940.80.

Beginning January 1, a new HCPCS code was created for ophthalmic mitomycin. HCPCS code J7315 Mitomycin, ophthalmic, 0.2mg can be reported for Mitosol, which, so far, is the only ophthalmic preparation of the drug that is FDA approved. Before the implementation of this code, some facilities reported J9280 Injection, mitomycin, 5mg for the ophthalmic use of mitomycin, however, this is not appropriate. J7315 has an N status indicator and N1 payment indicator per OPPS and the Medicare ASC payment system, respectively, and therefore no additional payment is made. Mitomycin is often used during trabeculectomy surgery to prevent scarring. As per the code descriptor for code 66172, injection of antifibrotic agents is not separately coded with this procedure.

Complications of the bleb such as bleb leak and bleb dysesthesia (discomfort) can occur after trabeculectomy surgery. When a revision of the bleb is performed after initial trabeculectomy surgery, code 66250 Revision or repair of operative wound of anterior segment, any type, early or late, major or minor procedure can be reported. Code 66250 belongs to APC 0233 and has a Medicare national payment rate of $1,129.46 under OPPS. It is paid at a Medicare national payment rate of $633.77 under the ASC payment system.

Canaloplasty
Canaloplasty or canalplasty refers to procedures that dilate Schlemm's canal, an endothelium-lined tube that drains aqueous humor from the anterior chamber into the bloodstream via the anterior ciliary veins. Obstruction of this pathway can cause increased intraocular pressure.

On January 1, 2011, 2 CPT Category III codes for dilation of Schlemm's canal were converted to Category I codes. Report 66174 Transluminal dilation of aqueous outflow canal; without retention of device or stent for dilation of the canal with fluid, after which a microcatheter is placed in the canal and then retracted as viscoelastic is injected to further dilate Schlemm's canal. The microcatheter is removed and the scleral flap that was created for access to Schlemm's canal is sutured closed.

When a stent or other device (polypropylene suture, for example) is placed to keep the canal patent, report 66175 Transluminal dilation of aqueous outflow canal; with retention of device or stent.

The canaloplasty procedures belong to APC 0673, per the OPPS, and are reimbursed at a Medicare national payment rate of $2,977.93. Under the ASC payment system, the Medicare national payment rate is $1,671.00.

The role of documentation
For the procedures we have considered, proper reimbursement for glaucoma requires accurate and thorough documentation. For each type of procedure, there may be 2 to 3 codes with differences based on the patient's ocular history, devices used or surgical approaches. Surgical landmarks such as the trabecular meshwork, Schlemm's canal and the suprachoroidal space must be clearly identified in the operative record for correct coding.

Especially for code 0192T Insertion of anterior segment aqueous drainage device, without extraocular reservoir; external approach, indications for the procedure should be clear and specific. Diagnosis codes for the exact type and severity of the glaucoma will help in getting these claims reimbursed. Review Medicare Local Coverage Determinations (LCDs) and private-payor contracts to verify what constitutes medical necessity for these procedures.

The devices used for each procedure should be clearly documented in the patient's medical record. Ideally, the surgeon should document within the operative note the exact type of device that he implanted. As was discussed, reimbursement for the majority of devices and medications used in conjunction with glaucoma surgery are considered included in the payment rate for the main procedure by Medicare. Review private-payor contracts to verify the reimbursement status of these device and medication HCPCS codes.