In a specialty contact lens practice, tools that are increasingly used are laboratory tests. These range from in-office testing for matrix metalloproteinase-9 (MMP-9) upregulation and tear film osmolarity to laboratory-processed corneal dystrophy testing. All of these tests can be used to confirm a diagnosis, to assess the candidacy of a medically necessary contact lens patient, or to diagnose dry eye. Because the tear film is the oil in the contact lens engine, being an expert in dry eye diagnosis is inextricably tied to specialty contact lens practice.

I was recently on a webinar during which the question came up of coding and billing for a new genetic test for keratoconus. The panel experts demurred on the subject. So, I thought that I would weigh in.

Tests for Dry Eye

There are two elements to laboratory testing. The first is the collecting of tissue or fluid samples to be assayed. The second is the lab test itself. Sometimes, these two elements are paid under the same code. For example, if you do an assay for MMP-9 upregulation, the correct Current Procedural Terminology (CPT) code is 83516: “Immunoassay for analyte other than infectious agent antibody or infectious agent antigen; qualitative or semi-quantitative, multiple step method.” This code includes the sample collection and the assay. It is a unilateral code with the bilateral exception. That means that you bill it twice if you perform it on both eyes, using the –RT and the –LT modifiers, and you will get paid 100% of the limiting charge for each eye.

If you are billing Medicare or Medicaid, you have to apply for and receive a Clinical Laboratory Improvement Amendments (CLIA) Certificate of Waiver. For information on how to do this, go to www.cms.gov/regulations-and-guidance/legislation/clia/downloads/howobtaincertificateofwaiver.pdf .

When billing Medicare or Medicaid, you need to designate the CLIA waiver by also appending the CPT code with the –QW modifier as well as with the laterality modifier. Also, place the CLIA waiver number in the appropriate box.

Another code that is used in this space is CPT code 83861: “Microfluidic analysis utilizing an integrated collection and analysis device, tear osmolarity.” If you are testing tear osmolarity, then you need to use this code. It is also a unilateral code with the bilateral exception. As with the 83516 code, a CLIA waiver is required in all instances to receive payment from government payors.

Corneal Dystrophy and Keratoconus

Finally, the new genetic test for corneal dystrophy and keratoconus is combined into one test. If you are testing for corneal dystrophy, then the proper CPT code is 81333: “TGFBI (transforming growth factor beta-induced) (eg, corneal dystrophy) gene analysis, common variants (eg, R124H, R124C, R124L, R555W, R555Q).” CMS Article A56199 states that these tier 2 codes are payable if the record documents medical necessity. So, if your record contains a differential diagnosis of a corneal dystrophy, then this code is appropriate for the testing lab to use.

However, this code does not cover the collecting of the sample or the supplies used. In this instance, the correct code would be the CPT Level II Healthcare Common Procedure Coding System (HCPCS) Code A9270: “Non-covered item or service.” Because this code is by definition a non-covered service, the collection materials, the sample collection, and the mailing costs should be billed directly to patients under this code.

Currently, there is no CPT code for the genetic testing of keratoconus. In this case, how the payment for the test itself is collected is between patient and practitioner. CLS