Q: What is the status of reimbursement for corneal pachymetry?

A: Once primarily used in cases of corneal disease, pachymetry is also part of the preop evaluation of patients contemplating corneal transplant and those with bullous keratopathy and Fuchs' dystrophy.

Last year's publication of the Ocular Hypertension Treatment Study highlighted an important, often overlooked correlation between corneal thickness and intraocular pressure in glaucoma detection. IOP measurements by applanation tonometry assume a standard corneal thickness of 550 µm. Applanation tonometry of an unusually thin cornea results in a false reading that is lower than the actual IOP. Thick corneas yield false high readings. Several conversion formulas exist to recalculate the IOP taking into consideration the corneal thickness.

Category III CPT codes describe emerging technology, services and procedures. First published in the 2002 CPT book, they allow data collection for services and procedures that do not have a Category I CPT code. Pachymetry is included in this section of CPT: 0025—Determination of corneal thickness (e.g., pachymetry) with interpretation and report, bilateral.
Category III codes may eventually receive Category I status by the American Medical Association. This may occur in the future for 0025T.
Pachymetry is also identified in the Health Care Procedure Coding System Manual: S0830—Ultrasound pachymetry to determine corneal thickness, with interpretation and report, unilateral. Private carriers use HCPCS codes; Medicare does not recognize them.

Q: Is pachymetry considered a covered service by Medicare and other third-party payers?

A: The existence of a code does not automatically indicate coverage. No national Medicare coverage policy exists, and reimbursement is currently at the discretion of the local carrier.

Two Medicare carriers published policies for coverage of corneal disease. These policies are quite old and do not reflect the current attitude toward the utility of this test for glaucoma. For example, Noridian published a policy for Iowa in 1996. It indicates 76999—unlisted ultrasound procedure as the appropriate code and the list of covered diagnosis codes is limited to a few corneal abnormalities.

Since OHTS, physicians have been very vocal about the utility of pachymetry for glaucoma patients. Draft coverage policies exist on some Medicare carrier websites and are available for comment. We urge physicians to review and comment on these draft policies for completeness and accuracy. Some carriers, such as Cigna, have published coverage notices in their bulletins. Check your bulletins to determine if yours has published information for pachymetry.

Q: If Medicare does not cover pachymetry, can I charge the patient?

A: Patients may be charged for pachymetry with proper notification and agreement from the patient and supporting documentation in the form of an advanced beneficiary notice. The ABN explains that your Medicare carrier will probably deny the claim due to a lack of a published payment policy for the diagnosis of glaucoma. You may collect your fee from the patient at the time of service or wait for the Medicare denial. File your claim as 0025T-GA. If the patient pays for the service and Medicare also pays, send a prompt refund to the patient unless you rebut the carrier's determination.

As yet, there are no relative value units (RVUs) assigned to Category III codes, thus no allowable fee published in the Medicare Physician Fee Schedule. The Iowa policy mentioned earlier cites 92286, endothelial cell count, as a comparable service. As carriers develop policies, they will likely establish a rate specific for that carrier.

Q: What are the documentation requirements?

A: Corneal pachymetry is considered a diagnostic test. Document it in the chart the same as other ophthalmic tests, including: patient's name and date of test; physician's order for the test with medical rationale; patient's consent for test (may be verbal); test results including corneal thickness measurements and reliability; interpretation of the test including diagnoses, indicated treatment, and prognosis; and physician's signature.

The treating physician should document the order for the test. Be sure the interpretation can be easily identified as a test interpretation and not part of the eye exam. As draft policies appear, we are seeing Medicare carriers willing to reimburse this service one time per lifetime unless medical necessity is documented to support the need to repeat the measurement. Patients who experience corneal changes due to trauma, surgery or corneal disease may require repeat testing. The documentation of medical necessity will determine whether it is reimbursed.

Q: Can pachymetry be performed on the same day as an office visit and/or other diagnostic test?

A: Currently, there are no bundles by the National Correct Coding Initiative that include pachymetry. Unless your carrier's local medical review policy imposes restrictions, it can be performed and billed on the same day as an office visit and/or other diagnostic test. (Noridian, the Medicare carrier for some Midwestern states, has published a draft policy that bundles pachymetry with office visits.)

Ms. McCune is a vice president of Corcoran Consulting Group.