Several diagnostic tests exist to diagnose and monitor corneal disease. Some tests, such as fluorescein and lissamine green staining of the cornea or Schirmer’s tear test, are components of an eye exam. Other tests, often prompted by the results of the earlier eye exam, are stand-alone services with unique CPT codes and separate reimbursement. This article discusses reimbursement considerations for specular microscopy also known as corneal endothelial photography.
Indications for Specular Microscopy
Indications for specular microscopy include, but are not limited to: bullous keratopathy, keratoconus, recurrent erosion of the cornea, corneal dystrophy, corneal ectasia, post-corneal transplant, and aphakia. The American Academy of Ophthalmology’s website discusses the usefulness of corneal endothelial photography. It states: 1
When properly done, corneal endothelial photography has been shown to be a relatively safe, reliable and effective means to ascertain corneal endothelial cell density (cells/mm2) and to provide information about endothelial cell morphometry. Currently, this procedure is not essential prior to routine cataract surgery, but may be indicated in situations in which the cornea is suspected of having endothelial abnormality and in which the accuracy of the estimated cell count from slit-lamp biomicroscopy is thought to be less than satisfactory. These situations include but are not limited to (1) eyes before secondary lens implantation; (2) eyes in which the status of the corneal endothelium is of concern because of a history of trauma, acute glaucoma, inflammation, or corneal transplantation; (3) eyes that contain intraocular lenses that are partially dislocated or are suspected of causing chronic inflammation or endothelial injury; and (4) eyes in which the fellow eye has a history of unexplained corneal edema.
Among the very few national Medicare coverage policies is one for endothelial cell counts (NCD 80.8)2. This longstanding policy provides that endothelial cell photography is a covered procedure under Medicare when reasonable and necessary for patients who meet one or more of the following criteria:
- Have slit lamp evidence of endothelial dystrophy (e.g. corneal guttata) (371.57)
- Have slit lamp evidence of corneal edema (371.20-371.24)
- Are about to undergo a secondary intraocular lens implantation (379.31)
- Have had previous intraocular surgery and require cataract surgery (V45.69)
- Are about to undergo a surgical procedure associated with a higher risk to corneal endothelium; i.e. phacoemulsification or refractive surgery (subject to some limitations for excluded refractive procedures)
- Have evidence of posterior polymorphous dystrophy of the cornea (371.58) or iridocorneal- endothelium syndrome (364.51, 371.57)
- Are about to be fitted with extended wear contact lenses after intraocular surgery (379.31, V43.1, V45.69)
In addition to photos of the endothelium or proof that digital images exist, the chart should contain:
- an order for the test with medical rationale
- the date of the test
- the reliability of the test (e.g, poor due to corneal scarring)
- the test findings (e.g. number of cells/mm2)
- a diagnosis (if possible)
- the impact on treatment and prognosis
- the signature of the physician
A form suitable for documenting the interpretation of specular microscopy and other tests is available on the Corcoran Consulting Group website.
Frequency of Tests
How frequently a test may be performed and filed for reimbursement is a common concern expressed by physicians. There are no published limitations for repeated testing using specular microscopy. In general, this and all diagnostic tests are reimbursed “when medically indicated” for new symptoms, disease progression, new findings, unreliable prior results, or a change in the treatment plan. In general, additional testing is warranted when the information garnered from the eye exam is insufficient to adequately assess the patient’s disease. Clear documentation of the reason for testing is always required. So, if a patient has a history of corneal dystrophy (or other indicated condition) and the eye exam reveals an unstable or worsening condition, then more extensive testing may be justified. We would not expect a claim to be filed for a stable patient who presents with no complaints, or one with a controlled condition.
Medicare Utilization Rates and Reimbursement
Medicare utilization rates provide a useful benchmark for physicians to compare themselves with their peers. The 2006 Centers for Medicare and Medicaid Services (CMS) Part B Extract Summary System (BESS) data reveals a utilization rate for ophthalmologists of 0.3% for specular microscopy. This percentage represents the occurrence per one hundred Medicare paid eye exams (i.e., for every 1,000 eye exams paid by Medicare to ophthalmologists, there were three (3) paid claims for specular microscopy.) Cornea specialists will likely have a higher utilization rate.
92286 is a unique CPT code which describes special anterior segment photography with interpretation and report; with specular endothelial microscopy and cell count. Specular microscopy is defined by CMS as “bilateral”, so reimbursement is for both eyes. The 2008 national Medicare fee schedule allowable is $121.12. Of this amount, $88.74 is assigned to the technical component and $32.37 is the value of the professional component. This amount is adjusted in each area by local wage indices. Other payers set their own rates, which may differ significantly from the Medicare published fee schedule. Medicare does not bundle specular microscopy with other diagnostic tests performed on the same day.
Reimbursement for Specular Microscopy in Postoperative Care
The classic global surgical package includes postoperative follow-up care. Certain services associated with surgery are not considered part of the package and are reimbursed separately. In Medicare's regulations, the global surgery package does not include diagnostic tests. Therefore, should it be medically necessary to perform specular microscopy in the postop period, the test is reimbursed. For example, following penetrating keratoplasty for a traumatized eye, the patient develops endothelial changes, such as guttae, and corneal edema which the surgeon follows carefully using specular microscopy. The postop eye exam would not be billed but specular microscopy would be. No special modifiers are required on the claim to obtain reimbursement for specular microscopy in this situation.
Specular microscopy continues to be an important and specialized diagnostic tool for the ophthalmologist and optometrist who are concerned about corneal dystrophies.
1 Published in Ophthalmology, August 1997, Vol. 104, 1360-1365
2 National Coverage Determination 80.8, Endothelial Cell Photography