coding q & a
Corneal Pachymetry Pearls
From what it is to Medicare coverage status to how much to charge for it.

By Suzanne Corcoran, C.O.E.

Q. What exactly is corneal pachymetry?

Answer: Corneal pachymetry is a measurement of the thickness of the cornea. The normal human cornea is approximately 550 µm thick centrally and a full millimeter thick peripherally. A pachymeter is most often used to measure the central cornea. Pachymetry is customarily ordered when a diseased cornea is edematous or ectatic; it is also used before laser-assisted in situ keratomileusis (LASIK) to help plan the photoablation.

Q. Is corneal pachymetry only warranted for corneal abnormalities?

Answer: Historically, yes, but the recent Ocular Hypertension Treatment Study has revealed that corneal thickness plays a significant role in glaucoma detection. Patients of certain races and those who have moderate to high myopia tend to have thinner corneas. Applanation tonometry of an unusually thin cornea results in a false reading that's lower than the actual intraocular pressure (IOP) because the resistance of the corneal tissue to indentation is less than expected.

The reverse is also true; thick corneas yield false high readings. Conversion formulas have been developed to mathematically "adjust" the IOP for an eye with an abnormally thin (or thick) cornea.

Q. How do I bill for corneal pachymetry?

Answer: 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?

Answer: No national policy for corneal pachymetry exists at this time, although that might change once the implications of the Ocular Hypertension Treatment Study are better appreciated. Reimbursement for 0025T is at the discretion of each Medicare carrier.

Q. If Medicare doesn't cover this test, can I charge the patient?

Answer: Yes. Explain to the patient why you believe the test is necessary, and that Medicare will likely 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.

Collect your fee from the patient at the time of service or wait for a Medicare denial. If both the patient and Medicare pay, be sure to refund the patient promptly.

Q. How much should I charge for this test?

Answer: Because there's no Medicare fee schedule amount defined, you may charge whatever you feel is reasonable. As a point of reference, before 2002, some people advocated using 76516 (ophthalmic biometry by ultrasound echography, A-scan) to describe ultrasonic pachymetry for each eye.

Q. What documentation do I need to include in the patient's chart?

Answer: Just as with other ophthalmic tests, the medical record should include:

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

Suzanne Corcoran is vice president of Corcoran Consulting Group.  Reach her at (800) 399-6565 or at SCORCORAN@CORCORANCCG.COM.