While gonioscopy is an old standby test, it sometimes still is misunderstood. Here’s a review.

Q. What is gonioscopy?

A. Gonioscopy is a diagnostic test for glaucoma and other disorders in which 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 assessment is done using a goniolens, a contact lens with a reflecting mirror or prism. Gonioscopy, most frequently performed at the slit lamp, takes place once the patient’s eye is numbed. Then the lens is placed on the cornea and the gonio lens’ mirrors facilitate a 360° view of the anterior chamber angle.¹

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.

Gonioscopy may be performed by an ophthalmologist, optometrist or other qualified health-care professional. It is not a test delegated to a technician, however well trained.

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 should gonioscopy be documented in the 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 (45- to 35-degree angle).

The Van Herrick system grades angles from Grade 1 (extremely narrow or closed) to Grade 4 (wide open). It compares peripheral anterior chamber depth to corneal thickness.

Scheie used roman numerals, Grade I to Grade IV, classifying angle depth based on structures visualized (ie, 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°), 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. What CPT code describes this test?

A. To report this test, use CPT 92020, Gonioscopy (separate procedure).

CMS defines 92020 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 or medical assistant.

The 2017 national Medicare Physician Fee Schedule allowable is $27; 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.

Q. What is the significance of the “separate procedure” designation in CPT?

A. The justification for an eye exam in addition to gonioscopy as a separate procedure is satisfied by two different diagnoses: one for the exam and another for the test. In this way, the “unrelated or distinct” provision is met. The CPT manual discussion of separate procedure states, “Some of the procedures or services listed in CPT that are commonly carried out as an integral component of a total service or procedure have been identified by the inclusion of the term, ‘separate procedure’. The codes designated as ‘separate procedure”’ should not be reported in addition to the code for the total procedure or service of which it is considered an integral component. However, when a procedure or service that is designated as a ‘separate procedure’ is carried out independently or considered to be unrelated or distinct from other procedures/services provided at that time, it may be reported by itself or in addition to other procedures/services…”.

Q. Are other tests or services bundled with gonioscopy?

A. According to Medicare’s National Correct Coding Initiative, gonioscopy is bundled with laser trabeculoplasty (65855). When these services are performed on the same day, gonioscopy is not separately payable unless it occurs at a separate session. The E/M service 99211 is also bundled with this test.

Q. How frequently is this test performed?

A. Medicare utilization rates for claims paid in 2015 show that gonioscopy was performed in conjunction with 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%.

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. OM

REFERENCE

1. American Academy of Ophthalmology information on gonioscopy. Direct and Indirect Gonioscopy. http://tinyurl.com/h8elrze . Accessed Jan. 4, 2017.

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