Ophthalmologic Techniques That Evaluate the Posterior Eye Segment for Glaucoma

POLICY NUMBER

A.9.03.06

DESCRIPTION

Several techniques have been developed to measure the thickness of the optic nerve and retinal nerve fiber layer as a method to diagnose glaucoma. Measurement of ocular blood flow is also being evaluated as a diagnostic tool for glaucoma.

Diagnosis and Management

A comprehensive ophthalmologic exam is required for the diagnosis of glaucoma, but no single test is adequate to establish diagnosis. A comprehensive ophthalmologic examination includes assessment of the optic nerve, evaluation of visual fields, and measurement of ocular pressure. The presence of characteristic changes in the optic nerve or abnormalities in visual field, together with increased intraocular pressure (IOP), is sufficient for a definitive diagnosis. However, some patients will show ophthalmologic evidence of glaucoma with normal IOPs. These cases of normal-tension glaucoma are considered to be a type of primary open-angle glaucoma. Angle-closure glaucoma is another type of glaucoma associated with an increase in IOP. The increased IOP in angle-closure glaucoma arises from a reduction in aqueous outflow from the eye due to a closed angle in the anterior chamber. Diagnosis of angle-closure glaucoma is detailed in the  Optical Coherence Tomography (OCT) of the Anterior Eye Segment medical policy.

Conventional management of patients with glaucoma principally involves drug therapy to control elevated intraocular pressures and serial evaluation of the optic nerve, to follow disease progression. Standard methods of evaluation include careful direct examination of the optic nerve using ophthalmoscopy or stereo photography, or evaluation of visual fields. There is interest in developing more objective, reproducible techniques both to document optic nerve damage and to detect early changes in the optic nerve and retinal nerve fiber layer before the development of permanent visual field deficits. Specifically, evaluating changes in retinal nerve fiber layer thickness has been investigated as a technique to diagnose and monitor glaucoma. However, IOP reduction is not effective in decreasing disease progression in a significant number of patients, and in patients with normal-tension glaucoma, there is never an increase in IOP. It has been proposed that vascular dysregulation is a significant cause of damage to the retinal nerve fiber layer, and there is interest in measuring ocular blood flow as both a diagnostic and a management tool for glaucoma. Changes in blood flow to the retina and choroid may be particularly relevant for diagnosis and treatment of normal-tension glaucoma. A variety of techniques have been developed, as described below. (Note: This policy only addresses techniques related to the evaluation of the optic nerve, retinal nerve fiber layer, or blood flow to the retina and choroid in patients with glaucoma).

Techniques to Evaluate the Optic Nerve and Retinal Nerve Fiber Layer

Confocal Scanning Laser Ophthalmoscopy

Confocal scanning laser ophthalmoscopy is an image acquisition technique intended to improve the quality of the eye examination compared with 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 retinal nerve fiber layer thickness. In addition, this technique does not require maximal mydriasis, which may be problematic in patients with glaucoma. The Heidelberg Retinal Tomograph is a commonly used technology.

Scanning Laser Polarimetry

The retinal nerve fiber layer is birefringent (ie, biorefractive), meaning that it causes 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 retinal nerve fiber layer thickness. Unlike confocal scanning laser ophthalmoscopy, scanning laser polarimetry can directly measure the thickness of the retinal nerve fiber layer. GDx is a common scanning laser polarimeter device. GDx contains a normative database and statistical software package that compares scan results with 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 completed in 10 minutes. Current instruments have added enhanced and variable corneal compensation technology to account for corneal polarization.

Optical Coherence Tomography

Optical coherence tomography uses near-infrared light to provide direct cross-sectional measurement of the retinal nerve fiber layer. The principles employed are similar to those used in B-mode ultrasound except light, not sound, is used to produce the 2-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. Optical coherence tomography analysis software is being developed to include optic nerve head parameters with spectral domain optical coherence tomography, analysis of macular parameters, and hemodynamic parameters with Doppler optical coherence tomography and optical coherence tomography angiography.

Pulsatile Ocular Blood Flow

The pulsatile variation in ocular pressure results from the flow of blood into the eye during cardiac systole. Pulsatile ocular blood flow can thus be detected by the continuous monitoring of intraocular pressure. The detected pressure pulse can then be converted into a volume measurement using the known relation between ocular pressure and ocular volume. Pulsatile blood flow is primarily determined by the choroidal vessels, particularly relevant to patients with glaucoma, since the optic nerve is supplied in large part by choroidal circulation.

Techniques to Measure Ocular Blood Flow

A number of techniques have been developed to assess ocular blood flow. They include laser speckle flowgraphy, color Doppler imaging, Doppler Fourier domain optical coherence tomography, laser Doppler velocimetry, confocal scanning laser Doppler flowmetry, and retinal functional imaging.

Laser Speckle Flowgraphy

Laser speckle is detected when a coherent light source such as laser light is dispersed from a diffusing surface such as retinal and choroidal vessels and the circulation of the optic nerve head. The varying patterns of light can be used to determine red blood cell velocity and retinal blood flow. However, due to differences in the tissue structure in different eyes, flux values cannot be used for comparisons between eyes. This limitation may be overcome by subtracting background choroidal blood flow results from the overall blood flow results in the region of interest.

Color Doppler Imaging

Color Doppler imaging has also been investigated as a technique to measure the blood flow velocity in the retinal and choroidal arteries. This technique delivers ultrasound in pulsed Doppler mode with a transducer set on closed eyelids. The examination takes 30 to 40 minutes and is most effective for the mean velocity of large ophthalmic vessels such as the ophthalmic artery, the central retinal artery, and the short posterior ciliary arteries. However, total blood flow cannot be determined with this technique, and imaging is highly dependent on probe placement.

Doppler Fourier Domain Optical Coherence Tomography

Doppler Fourier domain optical coherence tomography is a noncontact imaging technique that detects the intensity of the light scattered back from erythrocytes as they move in the vessels of the ocular tissue. This induces a frequency shift that represents the velocity of the blood in the ocular tissue.

Laser Doppler Velocimetry

Laser Doppler velocimetry compares the frequency of reflected laser light from a moving particle with stationary tissue.

Confocal Scanning Laser Doppler Flowmetry

Confocal scanning laser Doppler flowmetry combines laser Doppler flowmetry with confocal scanning laser tomography. Infrared laser light is used to scan the retina, and the frequency and amplitude of Doppler shifts are determined from the reflected light. Determinations of blood velocity and blood volume are used to compute the total blood flow and create a physical map of retinal flow values.

A number of confocal scanning laser ophthalmoscopy, scanning laser polarimetry, and optical coherence tomography devices have been cleared by the U.S. Food and Drug Administration (FDA) through the 510(k) process for imaging the posterior eye segment. For example, the RTVue XR optical coherence tomography Avanti™ (Optovue) is an optical coherence tomography system indicated for the in vivo imaging and measurement of the retina, retinal nerve fiber layer, and optic disc as a tool and aid in the clinical diagnosis and management of retinal diseases. The RTVue XR optical coherence tomography Avanti™ with Normative Database is a quantitative tool for comparing retina, retinal nerve fiber layer, and optic disk measurements in the human eye to a database of known normal subjects. It is intended for use as a diagnostic device to aid in the detection and management of ocular diseases. In 2016, the RTVue XR optical coherence tomography and Avanti™ with AngioVue™ Software was cleared by the FDA through the 510(k) process (K153080) as an aid in the visualization of vascular structures of the retina and choroid.

In 2012, the iExaminer™ (Welch Allyn) was cleared for marketing by the U.S. Food and Drug Administration (FDA) through the 510(k) process. The iExaminer™ consists of a hardware adapter and associated software (iPhone® App) to capture, store, send, and retrieve images from the PanOptic™ Ophthalmoscope (Welch Allyn) using an iPhone.

The table below lists selected devices cleared by the U.S. FDA for imaging the posterior eye segment.

Selected Ocular Imaging Devices Cleared by the U.S. Food and Drug Administration

POLICY

Analysis of the optic nerve and retinal nerve fiber layer in the diagnosis and evaluation of individuals with glaucoma or glaucoma suspects may be considered medically necessary when using scanning laser ophthalmoscopy, scanning laser polarimetry, and optical coherence tomography.

The measurement of ocular blood flow, pulsatile ocular blood flow, or blood flow velocity is considered investigational in the diagnosis and follow-up of individuals with glaucoma.

POLICY EXCEPTIONS

Federal Employee Program (FEP) may dictate that all FDA-approved devices, drugs or biologics may not be considered investigational and thus these devices may be assessed only on the basis of their medical necessity.

POLICY GUIDELINES

The coverage guidelines outlined in the Medical Policy Manual should not be used in lieu of the Member's specific benefit plan language.

This policy addresses techniques used to evaluate for glaucoma and does not address other ophthalmic conditions.

Medically Necessary is defined as those services, treatments, procedures, equipment, drugs, devices, items or supplies furnished by a covered Provider that are required to identify or treat a Member's illness, injury or Mental Health Disorders, and which Company determines are covered under this Benefit Plan based on the criteria as follows in A through D:

A.  consistent with the symptoms or diagnosis and treatment of the Member's condition, illness, or injury; and

B.  appropriate with regard to standards of good medical practice; and

C.  not solely for the convenience of the Member, his or her Provider; and

D.  the most appropriate supply or level of care which can safely be provided to Member. When applied to the care of an Inpatient, it further means that services for the Member's medical symptoms or conditions require that the services cannot be safely provided to the Member as an Outpatient.

For the definition of medical necessity, “standards of good medical practice” means standards that are based on credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, and physician specialty society recommendations, and the views of medical practitioners practicing in relevant clinical areas and any other relevant factors. BCBSMS makes no payment for services, treatments, procedures, equipment, drugs, devices, items or supplies which are not documented to be Medically Necessary. The fact that a Physician or other Provider has prescribed, ordered, recommended, or approved a service or supply does not in itself, make it Medically Necessary.

Investigative is defined as the use of any treatment procedure, facility, equipment, drug, device, or supply not yet recognized as a generally accepted standard of good medical practice for the treatment of the condition being treated and; therefore, is not considered medically necessary. For the definition of Investigative, “generally accepted standards of medical practice” means standards that are based on credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, and physician specialty society recommendations, and the views of medical practitioners practicing in relevant clinical areas and any other relevant factors. In order for equipment, devices, drugs or supplies [i.e, technologies], to be considered not investigative, the technology must have final approval from the appropriate governmental bodies, and scientific evidence must permit conclusions concerning the effect of the technology on health outcomes, and the technology must improve the net health outcome, and the technology must be as beneficial as any established alternative and the improvement must be attainable outside the testing/investigational setting.

POLICY HISTORY

5/1998: Approved by Medical Policy Advisory Committee (MPAC).

4/12/2001: Managed Care Requirements deleted.

5/2001: Reviewed by MPAC; investigational status remains.

2/7/2002: Investigational definition added.

5/2/2002: Type of Service and Place of Service deleted.

5/29/2002: Code Reference section completed.

11/2002: Reviewed by MPAC; Scanning Laser Polarimetry (SLP) changed to medically necessary.

7/2003: Reviewed by MPAC; "Description" section revised to be consistent with BCBSA, scanning laser ophthalmoscopy and optical coherence tomography are medically necessary for high risk individuals, scanning laser ophthalmoscopy, optical coherence tomography and scanning laser polarimetry are considered investigational as a method of monitoring disease progression in patients with glaucoma and as a screening test for glaucoma in the general population, measurement of pulsatile ocular blood flow or blood flow velocity with doppler ultrasonography is considered investigational in the diagnosis and follow-up of patients with glaucoma, FEP exception added.

11/1/2004: Code Reference section updated, CPT code 92135 moved to covered, ICD-9 procedure code 88.90 added covered codes, ICD-9 diagnosis code 250.00, 250.01, 250.02, 250.03, 250.10, 250.11, 250.12, 250.13, 250.20, 250.21, 250.22, 250.23, 250.30, 250.31, 250.32, 250.33, 250.40, 250.41, 250.42, 250.43, 250.50, 250.51, 250.52, 250.53, 250.60, 250.61, 250.62, 250.63, 250.70, 250.71, 250.72, 250.73, 250.80, 250.81, 250.82, 250.83, 250.90, 250.91, 250.92, 250.93, 360.21, 362.85, V19.0 added covered codes, ICD-9 diagnosis 365.00, 365.01, 365.02, 365.03, 365.04, 365.10, 365.11, 365.12, 365.13, 365.14, 365.15, 365.20, 365.21, 365.22, 365.23, 365.24, 365.31, 365.32, 365.41, 365.42, 365.43, 365.44, 365.51, 365.52, 365.59, 365.60, 365.61, 365.62, 365.63, 365.64, 365.65, 365.81, 365.82, 365.83, 365.89, 365.9 description revised and moved from non-covered to covered, CPT code 93875 added to non-covered codes.

1/10/2005: Code Reference section updated, ICD-9 diagnosis code 362.01, 362.02, 368.40, 368.41, 368.42, 368.43, 368.44, 368.45, 368.46, 368.47 added covered codes, HCPCS S0820 deleted.

11/16/2005: Code Reference section updated, ICD9 diagnosis codes 362.03 - 362.07 added.

3/17/2006: Policy reviewed, no changes.

12/19/2007: Coding updated per 2008 CPT/HCPCS revisions.

1/18/2008: Policy reviewed, no changes.

9/16/2008: Annual ICD-9 updates effective 10-1-2008 applied.

12/31/2008: Code reference section updated per 2009 CPT/HCPCS revisions.

08/03/2010: Policy Description revised to remove optic nerve head analyzers. Policy statement revised to remove optic nerve head analyzers and analysis of the optic nerve (retinal nerve fiber layer) in the diagnosis and evaluation of patients with glaucoma or glaucoma suspects may be considered medically necessary when using scanning laser ophthalmoscopy, scanning laser polarimetry, and optical coherence tomography. FEP verbiage revised in Policy Exceptions section. Code Reference section revised to add ICD-9 diagnosis codes to the Covered Codes Table:  115.02, 190.5, 190.6, 224.5, 224.6, 228.03, 360.11, 361.00 - 361.9, 362.00 - 362.9, 363.00 - 363.9, 364.21 - 364.24 and 368.15. A note was revised for CPT Code 33875 in the  Non-Covered Codes Table.

03/07/2011: Policy statement updated to add ocular blood flow as investigational. Added new CPT codes 92132, 92133, and 92134 to the Code Reference section. 

03/02/2012: Policy reviewed. Deleted outdated references from Sources section.

04/17/2013: Policy reviewed; no changes to policy statement. Added ICD-9 procedure code 38.25 to the Code Reference section and deleted 88.90 from the Code Reference section.

03/18/2014: Policy reviewed; description updated regarding FDA-approved device. Policy statement unchanged.

03/11/2015: Policy description updated with information regarding the comprehensive ophthalmologic exam. Policy statements unchanged.

08/31/2015: Code Reference section updated for ICD-10. Removed deleted CPT codes 0187T and 93875.

05/27/2016: Policy number A.9.03.06 added. Policy Guidelines updated to add medically necessary and investigative definitions.

09/23/2016: Policy description updated regarding devices. Policy statements unchanged.

03/29/2017: Policy title changed from "Ophthalmologic Techniques of Evaluating Glaucoma" to "Ophthalmologic Techniques That Evaluate the Posterior Segment for Glaucoma." Policy description updated regarding intraocular pressure and techniques to measure ocular blood flow. Investigational policy statement revised to remove "Doppler ultrasonography." It previously stated: The measurement of ocular blood flow, pulsatile ocular blood flow, or blood flow velocity with Doppler ultrasonography is considered investigational in the diagnosis and follow-up of patients with glaucoma. Policy guidelines updated to state that this policy addresses techniques used to evaluate for glaucoma and does not address other ophthalmic conditions.

09/29/2017: Code Reference section updated to add ICD-10 diagnosis codes H44.2A3, H44.2A9, H44.2B1, H44.2B2, H44.2B3, H44.2B9, H44.2C1, H44.2C2, H44.2C3, H44.2C9, H44.2D1, H44.2D2, H44.2D3, H44.2D9, H44.2E1, H44.2E2, H44.2E3, and H44.2E9, effective 10/01/2017. Removed deleted ICD-10 diagnosis codes E08.359, E09.359, E10.321, E10.359, E11.359, E13.321, E13.329, E13.331, E13.339, E13.341, E13.349, E13.351, E13.359, E08.359, E09.359, E10.321, E10.359, E11.359, E13.321, E13.329, E13.331, E13.339, E13.341, E13.349, E13.351, and E13.359.

04/11/2018: Policy reviewed; no changes.

04/08/2019: Policy description updated regarding devices. Policy statements unchanged.

04/17/2020: Policy reviewed; no changes.

05/27/2021: Policy reviewed. Policy statements unchanged. Policy Guidelines updated to change "Nervous/Mental Conditions" to "Mental Health Disorders" and "Medically Necessary" to "medical necessity."

05/19/2022: Policy description updated regarding devices. Medically necessary statement revised to change "Analysis of the optic nerve (retinal nerve fiber layer)" to "Analysis of the optic nerve and nerve fiber layer." Policy intent unchanged.

04/18/2023: Policy description updated regarding devices. Policy statements updated to change "patients" to "individuals."

09/28/2023: Code Reference section updated to make note of deleted ICD-10 diagnosis code.

04/23/2024: Policy description updated regarding devices. Policy statements unchanged.

12/19/2024: Code Reference section updated to add new CPT code 92137. Revised description for CPT codes 92132, 92133, and 92134. Effective 01/01/2025.

04/25/2025: Policy description updated regarding devices. Policy statements unchanged. Code Reference section updated to remove deleted ICD-10 diagnosis code H36.

SOURCE(S)

Blue Cross Blue Shield Association policy #9.03.06

CODE REFERENCE

This may not be a comprehensive list of procedure codes applicable to this policy. 

The code(s) listed below are ONLY medically necessary if the procedure is performed according to the "Policy" section of this document.

Covered Codes

Investigational Codes

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