Evaluating a patient for the presence of glaucoma is part of the daily routine for any optometrist. Still, knowing current parameters on what constitutes a glaucoma suspect and the appropriate coding may require a refresher, since the ICD-10 code for a glaucoma suspect is invalid to use—and with the frequency it is used, it can spell trouble for your practice.

Setting a Diagnosis

Although 304 ICD-10 codes contain the word glaucoma, only one exists for glaucoma suspect (H40.0). Yet, it’s not a proper code to use for diagnosis or for submitting to a carrier because it lacks specificity. 

According to the American Academy of Ophthalmology (AAO), the diagnosis of a primary open-angle glaucoma (POAG) suspect is established by the presence of one of the following: consistently elevated intraocular pressure (IOP), suspicious optic nerve or abnormal visual field. It could also have associated risks of elevated IOP, family history of glaucoma or glaucoma suspect, thin central cornea, race, older age, myopia and type 2 diabetes.¹

The diagnostic testing associated with a patient at risk, but not diagnosed, includes gonioscopy, pachymetry, tonometry, perimetry, careful optic nerve observation and ocular imaging. The term “ocular imaging” can include fundus photography and OCT based on the specific medical necessity of the patient.

These diagnosis codes (highest specificity only) can be used to pursue the necessary addi-tional diagnostic tests and are the only codes to be used for proper diagnosis of a glaucoma suspect:

• H40.00X: Pre-glaucoma
• H40.01X: Open-angle with borderline findings, low risk
• H40.02X: Open-angle with borderline findings, high risk
• H40.05X: Ocular hypertension

The physician must specifically identify with the highest level of specificity the patient’s type of “suspect.” Using the same code for all suspects because of convenience or routine is inappropriate.

When testing, clinicians should map the appropriate ICD-10 code to the appropriate procedure they are performing. Although the list of procedures is broad, clinicians should not perform the same tests on every patient. Instead, they must consider each patient on an individual basis and only order clinically relevant and necessary tests.

Ongoing Care

Once the clinician establishes the diagnosis—whether a specific form of glaucoma or simply at risk—they then use that ICD-10 code on subsequent visits when performing follow-up tests to monitor progress and treatment effect.

According to the AAO’s Preferred Practice Pattern for POAG, the ongoing clinical testing for a patient includes:² 92250 (stereo photography), 92133 (OCT of optic nerve) and 92083 (visual fields, threshold).

The frequency of testing is now based on two criteria: the patient’s condition and the insurance carrier’s guidelines. Most carriers allow one to two OCTs per year, generally alternated with a visual field. For stereoscopic photos, clinicians must establish necessity in the medical record each time they take a photo. Thus, if there is no change in the optic nerve noted in the physical exam, there is no necessity to photo-document “no change.” 

If clinicians must perform an extended optic nerve exam, the new (January 2020) code is 92202: ophthalmoscopy, extended; with optic nerve or macula drawing and I/R, unilateral or bilateral.

The additional criteria clinicians must meet stem from the National Correct Coding Initiative, or CCI edits. These rules stipulate what procedure codes can or cannot be performed on the same date of service. 

Too often, practitioners ignore the insurance carriers’ and the CCI edits’ rules. This leads to inappropriate use of modifiers (specifically -59) because claims get rejected. This is highly scrutinized by carriers, and doctors are fined for inappropriate clinical and coding procedures.

The proper identification of glaucoma is a vital part of the clinical evaluation, and clinicians must understand the CPT and ICD-10 rules it requires.

Send your coding questions to rocodingconnection@gmail.com.