glaucoma

Optimizing Your Glaucoma Practice

The key to your practice's success is an understanding of the tests and coding needed to manage patients who have glaucoma.

DEEPAK GUPTA, O.D., F.A.A.O., Milford, Conn.

Many optometrists play an integral part in diagnosing and managing patients who have glaucoma and those suspected of having glaucoma. As their primary eyecare providers, we need to keep up to date on ways to optimize our glaucoma practice to provide the highest levels of care.

Managing this patient group can be challenging, especially for those optometrists who find themselves in the early stages of developing a glaucoma practice. In most cases, patients who have glaucoma will undergo many different examinations and tests. These will include a comprehensive examination, visual field examination, gonioscopy, fundus photography, nerve fiber analysis and corneal pachymetry. In order to provide the optimum level of care for these patients, let's discuss each of these components of the exam separately and in greater detail.

Comprehensive eye exam

Any patient suspected of having glaucoma should have a comprehensive eye examination on an annual basis. Ideally, this should include dilation of the pupils. In addition to the "typical" components of a comprehensive examination, include specific exam components, such as an assessment of the visual system, slit lamp examination, measurement of intraocular pressure (IOP) and optic nerve and nerve fiber layer examination after pupil dilation.

● Comprehensive eye exam
● Gonioscopy
● Visual field testing
● Fundus photography
● Optic nerve and nerve fiber analysis
● IOP measurement
● Corneal pachymetry

For some patients, the information you gather from history taking may be enough to warrant the diagnosis of glaucoma suspect and lead you to order some form of glaucoma work-up. This information could include a history of elevated IOP, a family history of glaucoma, a history of iritis or ocular trauma. These risk factors may help you decide how aggressive you want to be with therapy. For example, patients with two or more risk factors or patients with certain risk factors (such as thin corneas) warrant aggressive treatment.

Other components of this examination — measurement of IOP and assessment of optic nerve status — may also lead to the diagnosis of glaucoma suspect.

Once you've identified the risk factors for glaucoma, you may order tests and diagnostic procedures to better help you diagnose or manage the condition. When doing this, your chart documentation must include an order for each specific test requested by you, the treating doctor. Include a short phrase indicating the request, for example, "order visual field in three months" or "gonioscopy/fundus photos performed today." Doing this provides a legitimate way of documenting that additional testing is necessary beyond the comprehensive eye examination.

To optimize your practice: When coding for the comprehensive eye exam, you have two basic options: evaluation and management (E/M) codes or eye codes.

The two most common codes we use for the comprehensive eye examination in my practice are 92004 (comprehensive eye exam, new patient) and 92014 (comprehensive eye examination, previous patient).

Gonioscopy
Code: 92020

The visual examination of the anterior chamber angle, or gonioscopy, is essential for the proper diagnosis and management of glaucoma. What we loosely refer to as glaucoma is actually primary open-angle glaucoma — but you can't call it that unless you've visualized the angle via a special gonioscopic lens and know that the angle is open. Many practitioners often overlook the procedure because they don't deem it necessary. This is because roughly 90% of all glaucoma cases are open angle glaucoma. What many of these practitioners forget, however, is that 10% have a secondary mechanism, such as… Therefore, you need information on this mechanism to properly manage these patients.

Something else to keep in mind: The configuration of the angle can change through time as a result of pupil size, ciliary tone, iris configuration and crystalline lens size, requiring gonioscopy for the proper long-term management of glaucoma as well.

To optimize your practice: Perform gonioscopy every year on a glaucoma patient whose IOP meets or falls below target and who has stable visual field test results. For billing purposes, you can perform gonioscopy-copy on the same day as the comprehensive eye exam.

Visual field testing
Code: 92083

The visual field (VF) test is the most common auxiliary test doctors order for glaucoma patients. Although many new methods have been developed to assess visual function in glaucoma and glaucoma suspect patients, perimetric evaluation of the glaucomatous visual field remains a cornerstone in the protocol.

The same VF codes apply for some of the new technologies in VF testing, such as the frequency doubling threshold (FDT) device. Because FDT is quick and easy to use, many practitioners order this test as a screening tool for high-risk (glaucoma?) patients. You can bill it as ICD Code 92081 (low level visual field). If the FDT demonstrates any abnormalities, order a more traditional full-threshold test.

VF results aren't bundled with other tests, so you can perform them on the same day as gonioscopy and a complete eye examination. Be aware, however, that most health insurers won't provide reimbursement if you perform a VF test on the same day as scanning computerized ophthalmic diagnostic imaging (92135). Also, many will not reimburse for VF testing if performed the same day as fundus photography.

To optimize your practice: Perform a VF test once a year on glaucoma patients or glaucoma suspect patients who have stable tests results. For more progressive, or high-risk cases, perform VF testing every six months, or every three months for advanced glaucoma.

One of the most common scenarios in which multiple VF testing is required: if the first VF test demonstrates glaucomatous defects or significant changes from previous tests. The purpose of the second test is to verify the test results and to check for repeat-able defects. In this case, you should receive reimbursement for both tests.

Fundus photography
Code: 92235

Stereo photography of the optic nerve head structure is the minimum standard of care for any glaucoma patient. In most cases, you'll perform fundus photography at the end of the comprehensive eye examination with the pupils dilated. Usually, health insurance will not reimburse fundus photography if you perform it on the same day as scanning computerized diagnostic imaging.

To optimize your practice: Perform stereo photography of the optic nerve head structure on an annual basis for most glaucoma and glaucoma suspect patients.

Optic nerve and nerve fiber analysis
Code: 92135

The analysis of the optic nerve and its surrounding peripapillary tissue or nerve fiber layer has rapidly been incorporated into standards of care in glaucoma workups. These instruments provide objective, reproducible measurements for the posterior pole and optic nerve structure and in doing so, facilitate the detection of subtle changes.

These tests are reimbursable under the code for scanning computerized ophthalmic diagnostic imaging (shown above). This test is typically billed as a unilateral procedure. However, if you perform the test on both eyes, bill each separately with a right and left modifier.

To optimize your practice: Generally, you can perform optic nerve and nerve fiber analysis once each year. For patients who have advanced glaucoma, this may be done every six months. In each case, you should include an order for the test as well as an interpretation.

IOP measurement

The measurement of IOP is an essential part of diagnosing and managing the glaucoma or glaucoma suspect patient. When done as part of a comprehensive or intermediate eye exam, it's considered an incidental component of an eye exam with no additional reimbursement. The most common scenario for IOP measurement is when you're following a patient who needs her IOP checked after three or four months. In such a case, bill this visit as an intermediate exam (92012). The doctor typically checks for any changes in health and vision, updates medications and checks IOP along with a slit lamp examination.

To optimize your practice: To indicate the medical necessity of the intermediate exam, include a phrase on the chart as simple as "follow-up primary open-angle glaucoma (POAG)" or "follow-up glaucoma suspect."

The one exception to the code is serial tonometry (92100). Tonometry is considered serial when you measure IOP at least three separate times during the course of one day. This test is most commonly used in patients who have suspected normal tension glaucoma (code 365.12).

Corneal pachymetry
Code: 76514

With the release of the Ocular Hypertension Treatment Study (OHTS), the corneal pachymeter quickly became part of the standard of care for glaucoma management.

The OHTS concluded that eyes with relatively thin corneas — 555μm or less — had a greater risk of developing glaucoma than those with thick corneas — 558μm or greater.

Effective in 2004, Medicare assigned a regular CPT code for pachymetry: 76514, ophthalmic ultrasound, echography, diagnostic; corneal pachymetry, unilateral or bilateral.

To optimize your practice: Test for corneal thickness on every patient who has glaucoma or who is a glaucoma suspect. Unlike other glaucoma testing, which is generally performed on annual basis, corneal pachymetry is only done once in an individual's lifetime.

Adapt your routine

To optimize diagnosis and treatment of glaucoma patients and those who are glaucoma suspects, practices must adapt their routines (increases in patient flow and testing, scheduling, proper medical billing, etc.) to accommodate patients who will visit the office more than annually. You will need to see most patients who have glaucoma every three months in your office for a total of four visits per year. Most patients who are glaucoma suspects should be seen every four months, for a total of three visits. In cases in which the patient's glaucoma is progressing or in cases of advanced glaucoma, the patient may need to visit your office more frequently.

In all situations, the key to optimizing your glaucoma practice is for you to administer the standard of care and bill appropriately for your services. Mastering both areas will provide the highest level of care for both your patients and your practice. OM

Dr. Gupta is author of the book, Glaucoma Diagnosis and Management. He practices full-scope optometry in Stamford, Conn. E-mail him at Deegup4919@hotmail.com.