coding & reimbursement
The Aqueous Shunt Alternative
Guidance for documenting this procedure.
By Suzanne L. Corcoran, COE

Shunts have saved many patients' eyes that were otherwise destined for pain and possible blindness. These implants provide an alternative when other glaucoma treatments have failed. In neovascular glaucoma and buphthalmos' patients, shunts may be the preferred approach.

Q. Does Medicare cover implantation of an aqueous shunt?
Yes, for medically necessary indications. These implants are intended to reduce IOP in glaucoma patients, where medical and conventional surgical treatments have failed.

Q. What is the code, and how much does it pay?
Use 66180 (Aqueous shunt to extraocular reservoir (e.g., Molteno, Schocket, Denver-Krupin shunts). If a scleral reinforcement graft is also performed, use 67255 (scleral reinforcement with graft). In 2006, the Medicare Physician Fee Schedule includes a national payment rate of $986 for 66180 and $730 for 67255. Multiple surgery rules apply, so the payment for the second procedure will be reduced by 50%. The specific allowable for each geographic area is determined by adjusting the national rate by the geographic practice cost indices.

Q. What about facility reimbursement?
Under Medicare's outpatient prospective payment system, each CPT code is assigned to an ambulatory payment classification (APC) with a corresponding payment rate. CPT 66180 is assigned to APC 673, and 67255 to APC 237. In 2006, the national rate for APC 673 is $1731 and for APC 237 it is $1713. Again, multiple surgery rules apply. Payments to ASCs are based on nine payment groups. 66180 is in group 5, and 67255 is in group 3. The national allowable for group 5 is $717 and for group 3 is $510. Multiple surgery rules apply, just as they do for physician services.

Q. Is the shunt device reimbursed separately?
In a hospital outpatient department (HOPD), the device and graft are bundled into their APC groups; no separate payment is made. In an ASC, the devices are paid separately, using HCPCS codes L8612 (aqueous shunt) for the glaucoma implants and L8610 (ocular implant) for the tissue graft if used. Payment rates vary by state, ranging from about $488 to $650 for the implants and $469 to $626 for the graft.

Q.What if a revision procedure is required?
Medicare will pay for the revision of a previously implanted shunt, using CPT code 66185 (Revision of aqueous shunt to extraocular reservoir). The Medicare Fee Schedule amount is $576. The procedure is included in APC 673 when performed in a HOPD. In an ASC, this procedure is included in Group 2, which has a Medicare allowable of $446.

Q. We've heard some controversy about coding for the ExPRESS Mini Glaucoma Shunt. What do you recommend?
The CPT code of choice to describe this procedure is still 66180 (aqueous shunt to extraocular reservoir). While some of the examples used in this description are out-of-date, it is important to note that the list is neither comprehensive nor exclusive. Furthermore, the language used can be understood to pertain to the ExPRESS, which is classified as an aqueous shunt by the FDA. It provides a channel for egress of fluid from the anterior chamber into an extraocular space or reservoir where it can be absorbed by the venous capillary system. While the reservoir is not a plate haptic, it isn't necessary that it be so. The term "reservoir" is not unique to 66180 or ophthalmology, but is broadly used here. The CPT Assistant, published by the AMA, provides guidance in the Sept. 2003 edition that states "...the devices listed in the code are examples only. If a different glaucoma drainage device is implanted, this code may be used to report it."

Q. What is the frequency for aqueous shunt procedures?
Usually, this procedure is performed on patients with tertiary glaucoma. As such, utilization rates are extremely low for the country as a whole. In the Medicare program, this procedure is performed about 7,000 times per year or about 4 times per 10,000 eye exams. For the subspecialist, rates will likely be higher than average.

Suzanne Corcoran is vice president of Corcoran Consulting Group. You can reach her at (800) 399-6565 or scorcoran@corcoranccg.com.