There are definitely a lot of opinions on this one so it’s often best to rely on what you can prove through documentation if audited.  What you have likely heard is that modifier -59 can be added to one of the procedures and you’d be paid.  Per CMS (see reference below), Modifier -59 should be used to “indicate that a procedure or service was distinct or independent from other non-E/M services performed on the same day”.  Sounds good so far.

However, it goes on to state “documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual”. (page 1 of the linked reference)

You could likely argue that the macula and optic nerve (or other area of the posterior segment) are “different sites”, but further documentation suggests that’s not a good idea: “Treatment of posterior segment structures in the eye constitutes treatment of a single anatomic site” (page 2 of linked reference)

So in the end, it’s entirely possible to code for both, use the -59 modifier and get paid.  But getting paid doesn’t mean that it’s correct and, if audited, you’d have trouble producing resources to combat the guidance from CMS.  That leaves two options in our view:

• Do both tests and make the patient aware that they’ll likely have to pay for one through the use of an Advance Beneficiary Notice
• Schedule the tests for different days

Reference: https://www.cms.gov/Medicare/Coding/NationalCorrectCodInitEd/downloads/modifier59.pdf