Article Date: 4/1/2005

The Essentials of Proper Glaucoma Coding

These guidelines will help you to obtain better reimbursement.
BY DEEPAK GUPTA, O.D., F.A.A.O., Milford, Conn.

In our roles as primary eyecare providers, we're fairly comfortable managing glaucoma patients. However, along with managing these patients, we must also properly code for their visits and obtain reimbursement for them. Therefore, let's get up to date on the basic guidelines for properly coding glaucoma and glaucoma suspect patients. The standard code sets used in optometric practices are comprised of the ICD-9 codes for diagnoses, the CPT codes for most procedures.

In general, proper reimbursement for testing performed on glaucoma or glaucoma suspect patients depends on the following four factors:

1. Proper coverage for the service

2. Proper justification for the service

3. Proper documentation of the service

4. Proper coding on the claim form (CPT and ICD-9).


Comprehensive eye exam

Code: 92004 new OR 92014 established. Perform this on every glaucoma (ICD-9 365.11) or glaucoma suspect (365.01) patient at least once each year. When coding for the exam, you basically have two options: evaluation and management (E/M) codes and eye codes. In the vast majority of patients, we usually go with the ophthalmology codes (920XX) because it's easier to meet the documentation requirements, particularly the history components.

Eye code visits are either comprehensive or intermediate for both new and established patients. For yearly examination, you'll most likely bill for the comprehensive eye examination. When differentiating between a new patient and an established patient, keep in mind that the definition of a new patient is one who hasn't received any professional services from you or one of your partners of the same specialty in the same group practice within the past three years.

Therefore, you may code a patient who you last saw in your office four years ago as a new patient even though technically, he's an established patient at your office. The two most common codes we use for the comprehensive eye examination are 92004 (comprehensive eye exam, new patient) and 92014 (comprehensive eye examination, previous patient).

When performing the comprehensive eye exam, you should include a chief complaint, history of physical illness, review of systems, medical history, family history and psychosocial history. Also include an assessment of gross visual fields and a basic sensorimotor examination. For your glaucoma patients, include specific exam components such as an assessment of the visual system, slit lamp examination, measurement of IOP and optic nerve and nerve fiber layer examination after pupil dilation.

Once you've identified the risk factors for glaucoma, you may order subsequent 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 the treating doctor. This is easily done by a short phrase indicating "order visual field in three months" or "gonioscopy/fundus photos performed today." Doing this provides a legitimate way of showing that additional testing is necessary beyond the comprehensive eye examination.

Additional testing. In most cases, when you want to order additional testing beyond the comprehensive eye examination, you should provide proper documentation to support its need. The most common items required for reimbursement are the following:

The CPT descriptions of documentation requirements for many ophthalmic diagnostic tests include the phrase, ". . . with interpretation and report." Once the appropriate individual has performed the test, you must document your interpretation of the results somewhere in the medical records. This doesn't have to be anything elaborate. It may merely be a brief phrase indicating if a test is "normal," "stable from a previous test" or "mild superior arcuate defect."

The interpretation should generally include a comment about the reliability of the test results (i.e., whether the patient was compliant and the quality of the photos), as well the impact the test results will have on the course of treatment (no treatment necessary, continue current medications, or add new medications). You can put this interpretation on a separate page from the examination record, as part of the assessment plan list and even write it on the test result directly. The most important factor is that you must use the results of any test or diagnostic procedure you order to help you diagnose and manage the disease.


Code: 92020. Visual examination of the anterior chamber angle is a valuable tool for the proper diagnosis and management of glaucoma. The initial evaluation of any newly diagnosed glaucoma or glaucoma suspect patient is complete only if it includes gonioscopic examination. Not only that, but proper long-term management of glaucoma requires gonioscopy at appropriate intervals because the configuration of the angle can change over time.

For a stable glaucoma patient who is at or below target IOP and stable visual fields, repeat the evaluation every one to two years. You should monitor a patient who has neovascular glaucoma or pigmentary glaucoma at more frequent intervals to check for any signs of progression. In terms of billing, gonioscopy is a bilateral procedure that can usually be done on the same day as the comprehensive eye exam.

Visual Field Testing

Code: 92083. Visual field evaluation has been a vital aspect of the diagnosis and management of glaucoma and 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. In terms of coding, three levels of visual field testing exist: 92081, 92082 and 92083. The last digit depends on the number of isopters in the test. In virtually all glaucoma and glaucoma suspect patients, you'll bill the 92083 code for a full threshold visual field examination.

In terms of logistics, a technician may administer the test (this is called the technical component of the VF) but proper documentation of the test is only complete when it includes the professional component (your interpretation). This interpretation is usually a short narrative describing the reliability of the results and the findings, as well as the clinician's impression and assessment.

CPT defines visual field tests as unilateral or bilateral. So if you're only doing one eye, attach the modifier -52 to indicate a reduced level of service when you bill. Also, under the National Correct Coding Initiative (NCCI), you can perform VF on the same day as gonioscopy and a complete eye examination. However, they generally won't get reimbursed if they're performed on the same day as a nerve fiber analysis or confocal laser scanning.

Typical practice. The most common scenario is to order a VF once a year on any glaucoma or glaucoma suspect patient. However, VF testing is permitted more than once a year if the situation dictates. For example, it's commonplace for the VF test to be repeated if the first field 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 repeatable defects. In this case, bill both as the 92083. Also, in advanced glaucoma or in patients who have poor IOP control, it may be necessary to perform this test every six months, or, rarely, every three months. As long as documentation is proper and you can justify this test, it should be okay.

Variations. The same codes apply for some of the newer technologies in VF testing, such as frequency doubling threshold (FDT). Because FDT is quick and easy to use, many doctors order it as a screening test for high-risk 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.

Fundus photography

Code: 92235. Stereo photography of the optic nerve head structure is the minimum standard of care for any glaucoma patient. This photography can take place in the form of actual photographs, which are kept in the patient chart or digital images stored on a computer. If the digital images are stored on a disc or a place separate from the patient's chart, you should document the place of that storage in the medical records as well as include a separate sheet where you record the photographic interpretation report that explains what you have documented in the photographs and what decisions and planning that you are basing on it.

Typical practice. In most cases, you'll perform fundus photography at the end of the comprehensive eye examination with the pupils dilated. Usually you can't perform it on the same day as scanning computerized diagnostic imaging or on the same day as VF testing as a result of NCCI Edits and/or Local Carrier Determinations.

Optic nerve and nerve fiber analysis

Code: 92135. Four main instruments (the HRT [Heidelberg Engineering], GDx [Laser Diagnostic Technologies], OCT [Carl Zeiss Meditec] and RTA [Talia Technology Inc.]) analyze the optic nerve, its surrounding peripapillary tissue or nerve fiber layer. Regardless of brand, these new machines have rapidly been incorporated into standards of care in glaucoma workups. These instruments prove objective, reproducible measurements for the posterior pole and optic nerve structure and in doing so, they make it easier to detect subtle changes that might otherwise go unnoticed. These tests are reimbursable under the code for scanning computerized ophthalmic diagnostic imaging (92135). This is billed as a unilateral procedure. If you do both eyes, bill each separately with a right and left modifier. Generally, you can perform this once each year. 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. Serial tonometry, which provides information about the diurnal fluctuation of IOP, requires at least three separate measurements in the course of a clinic day. You can bill it with the CPT code 92100.

Typical practice. 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, the most common thing to do is to 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. The indication for the visit can be as simple as "follow up primary open-angle glaucoma (POAG) or follow up glaucoma suspect."

The one exception 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 (365.12).

Corneal pachymetry

Code: 76514. With the release of the Ocular Hypertension Treatment Study, the corneal pachymeter has become part of the standard of care for any optometrist managing glaucoma. Effective Jan. 1, 2004, Medicare assigned a regular CPT code: 76514, ophthalmic ultrasound, echography, diagnostic; corneal pachymetry, unilateral or bilateral. This is something that should be done on every glaucoma and glaucoma suspect patient. You can perform the measurement of corneal thickness as often as you feel necessary; however, most insurances will reimburse it for only once in an individual's lifetime.

Beneficial all around

By properly coding for glaucoma services, not only will we better serve our patients, but we will better serve our practice as well.

Dr. Gupta practices full scope optometry and is a clinical director of The Center for Keratoconus at Stamford Ophthalmology. E-mail him at



Optometric Management, Issue: April 2005