LCD L35038: Scanning Computerized Ophthalmic Diagnostic Imaging

Compliance with the provisions in this policy may be monitored and addressed through post payment data analysis and subsequent medical review audits.

History/Background and/or General Information

Glaucoma

Glaucoma is a leading cause of blindness, and a disease for which treatment methods clearly are available and in common use. Scanning computerized ophthalmic diagnostic imaging (SCODI) allows for early detection of glaucomatous damage to the nerve fiber layer or optic nerve of the eye. It is the goal of these diagnostic imaging tests to discriminate among patients with normal intraocular pressure (IOP) who have glaucoma, patients with elevated IOP who have glaucoma, and patients with elevated IOP who do not have glaucoma. These tests can also provide precise methods of observation of the optic nerve head and can more accurately reveal subtle glaucomatous changes over the course of follow-up exams than visual field and/or disc photos. This can allow earlier and more efficient treatment of the disease process. The severity of glaucoma damage can be estimated as mild, moderate, severe or indeterminate.

Retinal Disorders

Retinal disorders are the most common causes of severe and permanent vision loss. SCODI is a valuable tool for the evaluation and treatment of patients with retinal disease, especially macular abnormalities. SCODI is able to detail the microscopic anatomy of the retina and the vitreo-retinal interface. SCODI is useful to measure the effectiveness of therapy, in determining the need for ongoing therapy, or cessation of therapy.

The retina is a complex tissue in the back of the eye that contains specialized photoreceptor cells called rods and cones. The photoreceptors connect to a network of nerve cells for the local processing of visual information. This information is sent to the brain for decoding into a visual image. The adjacent retinal pigment epithelium (RPE) supports many of the retina’s metabolic functions.

The retina is susceptible to a variety of diseases, including age-related macular degeneration (AMD), diabetic retinopathy (DR), retinitis pigmentosa (RP) and other inherited retinal degenerations, uveitis, retinal detachment, and eye cancers. Each of these can lead to visual loss or complete blindness.

The leading cause of visual loss among elderly persons is AMD, which has an increasingly important social and economic impact in the United States. As the size of the elderly population increases in this country, AMD will become a more prevalent cause of blindness than both DR and glaucoma combined.

DR is also a major cause of blindness. In the proliferative stage of the disease, newly formed, abnormal blood vessels can break through the retinal surface and hemorrhage into the normally transparent, gelatin-like vitreous in the middle of the eye. Scar tissue may subsequently form and pull the retina away from the back of the eye, causing a retinal detachment to occur.

Rare inherited retinal degenerations, typified by RP, result in the destruction of photoreceptor cells and the RPE.

Clinical evidence has shown that long-term use of chloroquine (CQ) and/or hydroxychloroquine (HCQ) can lead to irreversible retinal toxicity. SCODI may be indicated to provide monitoring of patients for the development of retinopathy during long-term therapy.

SCODI Techniques

There are several forms of SCODI tests that currently exist. SCODI testing includes scanning laser polarimetry (SLP), optical coherence tomography (OCT), and confocal scanning laser ophthalmoscopy (CSLO). These testing devices use videographic digitized images to make quantitative topographic measurements of the optic nerve head and surrounding retina. Although these techniques are different, their objective is the same. These methods are described below:

• Scanning Laser Polarimetry (SLP)

The retinal nerve fiber layer (RNFL) is birefringent, causing a change in the state of polarization of a laser beam as it passes. A 780-nm diode laser is used to illuminate the optic nerve. The polarization state of the light emerging from the eye is then evaluated and correlated with RNFL thickness. Unlike CSLO, SLP can directly measure the thickness of the RNFL. GDx® is a common example of a scanning laser polarimeter. GDx® contains a normative database and statistical software package to allow comparison to age-matched normal subjects of the same ethnic origin. The advantages of this system are that images can be obtained without pupil dilation, and evaluation can be done in about 10 minutes. Current instruments have added enhanced and variable corneal compensation technology to account for corneal polarization.

• Optical Coherence Tomography (OCT)

OCT uses near-infrared light to provide direct cross-sectional measurement of the retinal nerve fiber layer. The principals employed are similar to those used in B-mode ultrasound except light, not sound, is used to produce the 3-dimensional images. The light source can be directed into the eye through a conventional slit-lamp biomicroscope and focused onto the retina through a typical 78-diopter lens. This system requires dilation of the patient’s pupil.

• Confocal Scanning Laser Ophthalmoscopy (CSLO)

CSLO is a laser-based image acquisition technique, which is intended to improve the quality of the examination compared to standard ophthalmologic examination. A laser is scanned across the retina along with a detector system. Only a single spot on the retina is illuminated at any time, resulting in a high-contrast image of great reproducibility that can be used to estimate the thickness of the RNFL. In addition, this technique does not require maximal mydriasis, which may be a problem in patients with glaucoma. The Heidelberg Retinal Tomograph is probably the most common example of this technology.

Covered Indications

Anterior segment SCODI will be considered medically reasonable and necessary for evaluation of specified forms of glaucoma and certain disorders of the cornea, iris and ciliary body.

Posterior segment SCODI will be considered medically reasonable and necessary under the following circumstances:

• For the diagnosis and management of a patient who has mild, moderate, severe, or indeterminate stage glaucoma or who is suspected of having glaucoma.

• Monitoring patients being treated with chloroquine (CQ) and/or hydroxychloroquine (HCQ) for the development of retinopathy.

• The evaluation and treatment of patients with conditions affecting the optic nerve (e.g., optic neuropathy) or retinal disease (e.g., macular degeneration, diabetic retinopathy) and in the evaluation and treatment of certain macular abnormalities (e.g., macular edema, atrophy associated with degenerative retinal diseases).

Limitations

The following are considered not medically reasonable and necessary:

• SCODI is usually not medically reasonable and necessary when performed to provide additional confirmatory information regarding a diagnosis which has already been determined. Documentation should support that the SCODI test result was used for establishing a diagnosis, establishing a baseline prior to treatment, or for monitoring purposes.

• Fundus photography and posterior segment SCODI performed on the same eye on the same day are generally mutually exclusive of one another ( National Correct Coding Initiative [NCCI] Policy Manual for Medicare Services ). The provider is not precluded from performing both on the same eye on the same day when each service is necessary to evaluate and treat the patient. The medical record should clearly document the medical necessity of each service. Frequent reporting of these services together may trigger focused medical review.

• Screening (patient without signs or symptoms) for any condition is not medically reasonable and necessary.

Place of Services (POS)

For additional information on services performed in an Independent Diagnostic Testing Facility (IDTF), please refer to Local Coverage Determination (LCD) L35448 Independent Diagnostic Testing Facility (IDTF).

For frequency limitations, please refer to the Utilization Guidelines section below.

Notice: Services performed for any given diagnosis must meet all of the indications and limitations stated in this policy, the general requirements for medical necessity as stated in CMS payment policy manuals, any and all existing CMS national coverage determinations, and all Medicare payment rules.

Scanning computerized ophthalmic diagnostic imaging (SCODI) allows for the early detection of glaucomatous damage to the nerve fiber layer or optic nerve and has demonstrated clinical utility in facilitating earlier diagnosis and treatment as well as monitoring for progression and response to treatment. Evidence-based guidelines (2015 Academy of Ophthalmology [AAO] Preferred Practice Pattern [PPP] on Primary Open-Angle Glaucoma and 2010 American Optometric Association [AOA] Optometric Clinical Practice Guideline on Care of the Patient with Open Angle Glaucoma) identify SCODI as one technique that may be used to examine the optic nerve head (ONH) and/or retinal nerve fiber layer (RNFL). SCODI is often used to provide quantitative information to supplement the clinical exam of the optic nerve. SCODI is widely used in the posterior segment, whereas in the anterior segment, the use is still limited.

The evidence-based guideline from the AAO (2015 AAO PPP on Primary Angle Closure) indicates that anterior segment imaging should be considered when angle anatomy is difficult to assess on gonioscopy. There is good evidence demonstrating general agreement between findings on gonioscopy and anterior segment imaging, including ultrasound biomicroscopy and anterior segment optical coherence tomography (AS-OCT). However, AS-OCT is limited to evaluating the iridocorneal angle. AS-OCT is one technology that may prove useful in evaluating secondary causes of angle closure and elucidating plateau iris.

SCODI is also a valuable tool for the evaluation of patients with retinal disease, especially those with macular abnormalities. SCODI is often used in conjunction with clinical examination of the eye. It is at times used as a baseline and also used in monitoring for progression or response to treatment. The clinical utility of OCT imaging in retinal conditions has been demonstrated as providing an objective, accurate assessment of the amount and location of retinal thickening. Evidence-based guidelines from the AAO (PPP Diabetic Retinopathy [2016] and the PPP Idiopathic Macular Hole [2014, updated 2017]) support that in clinical practice, decisions are often based on OCT findings.

Finally, Marmor et al (AAO Statement 2016) published recommendations on screening patients who are being treated with Chloroquine and Hydroxychloroquine. A baseline test is performed and then ongoing monitoring at regular intervals is recommended. Marmor et al recommends beginning annual screening after 5 years for patients on acceptable doses of chloroquine or hydroxychloroquine and without any major risk factors.