Perimetry is a well-established test for diagnosing, monitoring, and managing glaucoma. Within the Medicare program, 10% of all examinations performed by ophthalmologists include an evaluation of visual fields (CPT 92081, 92082, or 92083) (Table 1). According to Medicare's paid claims database for 2007, the most recent year for which this information is available, 95% of all perimetric tests performed use a threshold strategy to test visual fields. Nevertheless, my experience with retrospective chart reviews has shown that perimetry is more often underutilized than overutilized, probably because patients are not too happy to take the test.

Performing perimetry and billing for the procedure require the consideration of several factors. One must evaluate the standards of care for visual field testing, the Centers for Medicare & Medicaid Services' (CMS) and other third party payers' policies, the circumstances affecting individual patients, and the notations in the medical record.

STANDARD OF CARE
The AAO's Preferred Practice Patterns are useful references for standards of care in ophthalmology. These carefully written treatises on clinically relevant topics, combined with the body of scientific papers published in peer-reviewed journals, constitute an objective testament on medically necessary care. In general, visual field testing is warranted once a year for borderline or controlled glaucoma, twice a year for uncontrolled glaucoma, and three times a year for unusual cases (ie, monocular patients).

On an individual basis, the frequency of testing during a continuous 12-month period varies depending on several factors such as

  • The severity of glaucomatous damage (ie, none, mild, moderate, or severe)
  • The disease's progression
  • The extent to which the IOP exceeds the target pressure
  • The number and significance of other risk factors for damage to the optic nerve
  • The reliability of the test (ie, patient cooperation, learning effect, and suspicious findings).

Medicare's Payment Policy
The CMS' National Coverage Determination (NCD) manual (Section 80.9: Computer Enhanced Perimetry [Rev.1, 10-03-03] CIM 50-49) states

Computer enhanced perimetry involves the use of a microcomputer to measure visual sensitivity at preselected locations in the visual field. It is a covered service when used in assessing visual fields in patients with glaucoma or other neuropathologic defects.

In the absence of any other local coverage policy, the NCD controls reimbursement. By way of amplification, the introduction to the NCD manual states

Where coverage of an item or service is provided for specified indications or circumstances but is not explicitly excluded for others, or where the item or service is not mentioned at all in the CMS Manual System, the Medicare contractor is to make the coverage decision, in consultation with its medical staff, and with CMS when appropriate, based on the law, regulations, rulings, and general program instructions.

Consequently, providers should consult their local Medicare carrier's policy for additional information about covered indications, limitations, and diagnoses beyond those listed in the NCD. Where Local Coverage Determination (LCD) policies exist, they often contain language such as

Visual field testing may be medically necessary in a glaucoma suspect or a patient with glaucoma, mild damage, and good control only once a year. Field testing may be necessary in patients with moderate or advanced glaucoma and good control once a year. Field testing may be necessary in mild, moderate, or advanced glaucoma and borderline control two times a year. Finally, visual field testing in patients with uncontrolled glaucoma may be necessary up to four times a year.

According to these instructions, beneficiaries may be financially responsible for testing that exceeds the ceilings indicated in the LCD. Physicians who expect reimbursement must ask the Medicare beneficiary to sign an Advance Beneficiary Notice of Noncoverage before he or she undergoes repeat testing, because many LCDs state that "claims for visual field testing submitted at a frequency greater than is necessary for the reasonable medical management of the disease may be denied."

CHOICE OF VISUAL FIELD
The kind of visual field test performed may have a bearing on the frequency of testing. Although automated threshold perimetry is the most popular technique for assessing visual fields, other methods (eg, short wavelength automated perimetry, frequency doubling perimetry, motion detection perimetry) may be easier to administer, more acceptable to patients, and more sensitive to changes in visual fields. Sometimes, two visual field tests (ie, abbreviated and intensive) are performed on the same day. According to the National Correct Coding Initiative, the codes for visual field testing are mutually exclusive. For example, if a clinician performed 92082 and, based on the results, also decided to perform 92083, only the test with the higher value would be billed. In addition, E/M service 99211 (established, minimal exam) is bundled with perimetry of any type. Although the codes for visual field testing are not bundled with those for scanning computerized ophthalmic diagnostic imaging (92135), some Medicare administrative contractors and other third-party payers question the medical necessity of performing both tests on the same day. Staggering these tests over several consecutive office visits may help physicians avoid quixotic payment policies.

DOCUMENTING VISUAL FIELDS
The information physicians enter into medical records is a powerful indicator of their process of thought and their judgment about individual patients' disease and care. Whereas some notations are explicit and clearly state the physician's observations and assessments, others are less detailed and require the reader to infer his sentiment. For example, a note stating that a patient has poorly controlled IOP clearly describes the physician's objective observation. The same statement also obscures or merely implies the reason for the patient's uncontrolled IOP. While documenting the results of visual field testing in patients' medical charts, physicians should include the following essential elements:

  • An order for the test that clearly describes the medical rationale for its necessity
  • The date of the test
  • An assessment of whether the test was reliable
  • The results of the test, including noteworthy findings (if any)
  • The implications of the test, including the diagnosis (if possible)
  • The impact of the test results on the patient's treatment and/or prognosis
  • The physician's signature

The reviewer uses the notations in patients' charts to answer the question, "Should I reimburse the physician for this claim?" Sometimes, the physician who ordered and interpreted the test is asked to provide additional information, particularly if the claim is submitted for patients with complex or unusual underlying medical conditions (eg, multifactorial disease, pediatric conditions).

Payers frequently deny claims because the documentation on the chart shows that

  • Visual field testing was performed based on "standing orders"
  • Visual field testing was ordered by someone who is not treating the beneficiary (Code of Federal Regulations 410.32)
  • Visual field testing was ordered for an indication that is not covered by the payment policy
  • Visual field testing was not performed under the supervision of an individual meeting the definition of a physician (Program Memorandum B-01-28)
  • The visual field was not interpreted

In some cases, perimetric tests clearly do not yield valid results, and therefore they should not be submitted for reimbursement. Tests may be considered inadequate when the instrument malfunctions, the patient does not follow instructions, or the protocol was aborted prior to completion. Some imperfect tests, however, such as a patient's very first perimetric evaluation, are not worthless and merit reimbursement when they were performed for a covered indication.

CONCLUSION
The answer to the seemingly simple question of how frequently physicians can expect to receive reimbursement for repeat visual field testing is, "it depends." No single answer suffices. Physicians who consider the factors discussed in this article may develop a richer and more nuanced appreciation for how and when they should repeat visual field testing. If my experience in reviewing charts is accurate, perimetry is a valuable but significantly underutilized diagnostic tool in ophthalmic practices.

Kevin J. Corcoran, COE, CPC, FNAO, is the president of Corcoran Consulting Group. Located in San Bernardino, California, the firm specializes in reimbursement issues for ophthalmology and optometry. Mr. Corcoran may be reached at (800) 399-6565; kcorcoran@corcoranccg.com.