OCT angiography (OCTA) is a revolutionary imaging technology that has been cleared by the Food and Drug Administration.¹ The first OCTA instrument became commercially available in the United States in September 2015. This imaging technique has the potential to totally replace intravenous dye-based angiography for most macular diseases. Currently, these dye-based angiographic methods, which include fluorescein and indocyanine green angiography, are considered the gold standards for imaging diseases of the retinal and choroidal vasculature. Both dye-based angiographic methods require the intravenous infusion of fluorescent dyes followed by a series of photographs using bright flashes of light into a dilated pupil and special filters that are arranged to excite and then detect the fluorescent dyes as they circulate through the blood vessels in the back of the eye. These bright flashes of light are performed for 5 to 30 minutes as the images are acquired.

Both traditional angiographic techniques require the infusion of dye through a needle in an arm vein, and the dyes have side effects. They can cause nausea, and, in very rare instances, allergic reactions and even anaphylactic responses that can cause death. These dye-based imaging techniques may be uncomfortable and can pose risks for the patient. They are also cumbersome, and very operator dependent. Missing even a few seconds when photographing an eye after the injection of dye can result in an incomplete angiogram in which vital information is lost.

In contrast to dye-based angiography, OCT uses only a dim light that isn’t detected by the human eye. This light is used to scan the back of the eye. Based on subtle variations in how the light is reflected back to a detector, the OCT instrument is able to reconstruct the structural anatomy of the eye. OCT is ideal for imaging the macula and the optic nerve. But, traditional OCT instruments cannot image the fine blood vessels in the back of the eye. For this reason, OCT and dye-based angiography are often used together since both technologies provided complementary information that is helpful in the diagnosis and management of retinal and choroidal diseases.

FASTER AND SAFER, YET MORE EXPENSIVE

OCTA requires expensive hardware and software upgrades to perform the angiographic technique. An OCTA scan takes slightly longer than a traditional OCT scan to acquire; however, to obtain the OCTA images, additional processing time is required, and the clinician must interact with the software and manipulate the scans to get the best possible images of the vasculature. For the patient, OCTA is faster, safer, and easier than dye-based angiography, and for the clinician, it provides a wealth of detailed vascular information that combines the benefits of dye-based angiography with traditional OCT imaging.

But, these additional benefits come at the expense of purchasing a new instrument or upgrading an existing instrument, in addition to the extra time from the clinician to interpret the scans. This additional time may be substantial is some cases, especially when artifacts are present in the image. While OCT angiographic scans take longer to interpret compared with traditional OCT and dye-based angiography, the images that are finally produced can surpass those of dye-based angiography, especially when the most expensive technology is used. In addition, from the same OCT scan that produces the angiographic images, it’s also possible to extract the traditional OCT structural images.

Of course, there are different OCT angiographic instruments with the highest priced instruments producing some of the most spectacular images. The imaging technology can be separated into two different platforms: spectral-domain OCTA (SD-OCTA) and swept-source OCTA (SS-OCTA). Both platforms are more expensive than traditional OCT instruments. SD-OCTA instruments cost in the range of $80,000 to $100,000, while the only SS-OCTA instrument that is cleared by the FDA costs $150,000.

Although SD-OCTA is the most commonly used technology, SS-OCTA may eventually dominate the market in the future due to its ability to provide higher quality images of anatomy under the retinal pigment epithelium and to perform faster scanning rates, which allows for denser scans and larger fields of view for a given acquisition time. Not only are OCT angiography instruments more expensive, but these scans require much more storage capacity resulting is a significant increase in costs for data storage and retrieval.

THE ECONOMIC AND ETHICAL DILEMMA

Most clinicians would choose OCTA over dye-based angiography for the diagnosis and management of their own macular disease. However, most clinicians are caught between what’s best for the patient and what’s financially feasible for their practice. To perform OCTA, a clinician must purchase a new expensive instrument, but the reimbursement from Medicare for performing and interpreting an OCT scan is unchanged. The solution seems obvious. OCTA should get its own CPT code and get reimbursed at a higher amount than traditional OCT, but at a lower amount than dye-based angiography. While this may seem like a simple solution, the process of getting a new CPT code with an increased reimbursement is a risky undertaking. Once the process is initiated, it’s entirely possible that Medicare would lower the reimbursement for standard OCT imaging and reimburse clinicians for OCTA at the same amount that is currently being reimbursed for traditional OCT.

Not only is this unfair to the average clinician, who has already seen their OCT reimbursement substantially cut over the years and relies heavily on traditional OCT for the routine management of their patients, but it is also unfair to the clinicians who have decided to switch to OCTA from dye-based angiography in the interest of patient safety and comfort. We fear that the real-world result would be that most clinicians would decide not to upgrade their OCT instruments. This scenario should be considered untenable for the patient. Patients deserve the safest, most comfortable, and most informative imaging technology for the diagnosis and management of their disease, but if clinicians adopt this technology, then they will suffer a financial penalty.

Possible solutions to this economic and ethical dilemma:

1. Request a new CPT code for OCTA.
2. Request that the current OCT CPT code remains unchanged, but a new CPT code be provided that increases the reimbursement for the professional component of OCTA to cover the added time and effort required for the interpretation of these scans.
3. Request a premium OCT designation for OCTA so clinicians are permitted to charge patients directly, outside of Medicare, for the added benefit of OCTA. This strategy would be modeled after the premium IOL designation currently permitted by Medicare for the implantation of multifocal IOLs.

THE BURDEN OF PROOF IS ON US

As clinicians interested in providing the best possible care for our patients, we have the responsibility to educate regulatory agencies about the benefits of OCTA. Peer-reviewed articles continue to accumulate in our journals showing the benefits of OCTA for the diagnosis and management of macular diseases, and we have no doubt that evidence already exists documenting the patient-based benefits of OCTA in ophthalmology. It’s time to start working with the American Academy of Ophthalmology and our specialty societies to help us bring this safe, informative technology to our patients. RP

REFERENCE

1. Kashani AH, Chen CL, Gahm JK, et al. Optical coherence tomography angiography: a comprehensive review of current methods and clinical applications. Prog Retin Eye Res. 2017;60:66-100.