Coding & Reimbursement

Gonioscopy and Your Coding Questions

By Suzanne L. Corcoran, COE

Gonioscopy is a diagnostic test that has been available to ophthalmologists for many years, and continues to be valuable. Questions about Medicare rules and reimbursement still persist, however; this Q&A will attempt to clear up the confusion.

Q. How is gonioscopy defined by CPT?

A. For readers requiring clarification, CPT defines gonioscopy as a diagnostic test wherein the examiner looks at the trabecular meshwork and adjacent structures located in the angle of the anterior chamber of the eye, where the iris and the cornea meet. This is done using a goniolens, a contact lens with a reflecting mirror or prism.

Most frequently performed at the slit lamp, the eye is numbed, the lens is placed on the cornea and the goniolens mirrors facilitate a 360-degree view of the anterior chamber angle. CPT code 92020, Gonioscopy (separate procedure), describes this service.

Q. What diagnoses support claims for gonioscopy?

A. Indications for gonioscopy include, but are not limited to: rubeosis, glaucoma, hypotony, occlusive disorders, diabetic retinopathy, aphakia, intraocular foreign body, and subluxated or dislocated lens. Note that this list is neither exhaustive nor universally recognized.

Q. Who may perform this test?

A. Ophthalmologists and optometrists perform gonioscopy. It may not be delegated to a technician.

Q. Are there any additional guidelines for this test?

A. The American Academy of Ophthalmology's Preferred Practice Patterns discusses the usefulness of gonioscopy in glaucoma for “careful evaluation of the anterior-chamber angle to exclude angle closure or secondary causes of IOP elevation such as angle recession, pigment dispersion, peripheral anterior synechiae, angle neovascularization, and trabecular precipitates.”

Q. How is gonioscopy documented in the patient's medical record?

A. Several well-known glaucoma specialists have developed various methods for documenting gonioscopic findings.

► The most popular system, the Shaffer system, is based on the angular width of the angle recess; chart notations range from slit (0 degree angle) to Grade 4 (35 to 45 degree angle).
► The Van Herrick system grades angles from Grade 1 (extremely narrow or closed) to Grade 4 (wide open). This system compares peripheral anterior chamber depth to corneal thickness.
► Scheie makes use of Roman numerals, Grade I – Grade IV, classifying angle depth based on structures visualized (i.e., Grade IV = Only Schwalbe's line visible).
► The Spaeth grading system describes the configuration of the anterior chamber angle. It uses a series of capital letters (A-E) describing iris insertion, followed by angular approach (0 to 50 degrees), and then small letters describing the peripheral iris's configuration. An example of this documentation is D40r. Each letter correlates to a descriptor. In this example, D = Deep with ciliary body visible and r = regular.

Q. How frequently may this test be performed?

A. Repeated testing is indicated when medically necessary for new symptoms, disease progression, new findings, unreliable prior results or a change in the treatment plan. In general, additional testing is warranted when the information garnered from the eye exam is insufficient to adequately assess the patient's disease.

So if a patient has a history of glaucoma (or other indicated condition) and the eye exam reveals an unstable or worsening condition, then more extensive testing may be justified. We would not expect a claim to be filed for a stable patient who presents with no complaints or one with a controlled condition.

Medicare utilization rates for claims paid in 2009 show that gonioscopy was performed in about 3% of all office visits by ophthalmologists. That is, for every 100 exams performed on Medicare beneficiaries, Medicare paid for this service three times. For optometrists, the frequency is about 2%.

Q. What is the reimbursement for CPT 92020?

A. Code 92020 is defined by CMS as “bilateral,” so reimbursement is for both eyes. Unlike most other ophthalmic diagnostic tests, gonioscopy is not subdivided into a technical and professional component because no portion of the test can be delegated to a technician.

The 2011 national Medicare Physician Fee Schedule allowable is $26.16. This amount is adjusted in each area by local wage indices. Other payers set their own rates, which may differ significantly from the Medicare published fee schedule. OM

Suzanne L. Corcoran is vice president of Corcoran Consulting Group. She can be reached at (800) 399-6565 or www.corcoranccg.com.