Coding and Reimbursement
Corneal Pachymetry Update
As new uses for this test are found, the importance of getting properly reimbursed increases. Here's help.

BY SUZANNE L. CORCORAN, COE

As you know, corneal pachymetry is a measurement of the thickness of the cornea. (A normal human cornea is about 550 microns thick centrally and a full millimeter thick peripherally; a pachymeter is most often used to measure the central cornea.) Traditionally, doctors have only ordered pachymetry when a diseased cornea is edematous or ectatic, or used pachymetry before LASIK to help plan the photoablation.

Now, however, corneal pachymetry has a new use that's drawing attention. A recent study -- the Ocular Hypertension Treatment Study -- has revealed that corneal thickness plays a significant role in glaucoma detection.

Q. How does corneal pachymetry help detect glaucoma? Patients of certain races, as well as those with moderate to high myopia, often have thinner-than-average corneas. Applanation tonometry of an unusually thin cornea can produce a false reading that's lower than the actual IOP because the resistance of the thin corneal tissue to indentation is less than the resistance provided by a thicker cornea. The reverse is also true; thick corneas can yield false high readings.

A pachymeter provides the data regarding corneal thickness that's necessary to compensate for this difference. Researchers have developed conversion formulas to mathematically "adjust" the measured IOP for an eye with an abnormally thick or thin cornea.

Q. How do I bill for corneal pachymetry? As of January 1, 2002, CPT includes Category III codes to track new technology. Specifically, 0025T is defined as: Determination of corneal thickness (e.g., pachymetry) with interpretation and report, bilateral.

Q. Does Medicare cover corneal pachymetry? Medicare has no national policy for corneal pachymetry at this time, although that might change once the implications of the Ocular Hypertension Treatment Study are better appreciated. For now, reimbursement for 0025T is at the discretion of each Medicare carrier.

Q. What if Medicare doesn't cover corneal pachymetry? Can I charge the patient? Yes. Explain to the patient why you believe the test is necessary, and that Medicare will probably deny the claim. Ask the patient to assume financial responsibility for the charge. Get the patient's signature on an Advance Beneficiary Notice (ABN) and submit your claim as 0025T-GA.

You can collect your fee from the patient at the time of service, or you can wait for a Medicare denial before charging the patient. If both the patient and Medicare end up paying, be sure to promptly refund the patient.

Q. How much should I charge? Since no amount is listed on the Medicare fee schedule, you may charge whatever you feel is reasonable.

As a point of reference, before this year (2002) some people advocated using 76516 (ophthalmic biometry by ultrasound echography, A-scan) to describe ultrasonic pachymetry for each eye. However, those carriers that do cover this test pay a wide range of different fees, so no clearcut guideline exists at the moment.

Q. What documentation is required in the chart? Like other ophthalmic tests, the medical record should include:

• the patient's name and the date of the test
• an order for the test with the medical rationale
• the patient's consent for the test
• test results, including corneal thickness measurements, reliability, and interpretation
• the physician's signature.

Suzanne L. Corcoran, COE, is vice president of Corcoran Consulting Group. She can be reached at (800)399-6565 or via e-mail at scorcoran@corcoranccg.com.