Ultrasonography Standard of Care

NC Board Investigative Committee – Ocular Ultrasonography – Unanimous Opinion Relative to Scope of Practice – Appropriate Standards and Indications

This issue was generated by a NC licensed optometrist who was denied a Medicare claim for ultrasound (A & B scans) relative to monitoring a choroidal nevus. The denial referenced that this was not a procedure within the scope of practice of a NC licensed optometrist. The following is the optometrist’s inquiry to the Board office:

“Subject: Re: Medicare denial of services

Re: CPT 76510 B-Scan + Quantities A-Scan

This patient was found to have what was believed to be a Choroidal Nevus, ICD 224.6 and is asymptomatic in this regard.

B-Scan + Quantitative A-Scan ,CPT 76510, was needed to identify the lesion’s thickness and other characteristics such as fluid content and "back shadowing" in order to differentiate it from a choroidal melanoma as well as to follow its potential slow growth or change of characteristics over time.

Choroidal Nevi do not need to be referred, but followed. Choroidal tumors may need to be referred.

As a result of the procedure being performed, it was determined that this lesion is most likely a choroidal nevus at this time; however, it will need to be repeated in the future to identify change, if any.

As a result, I will follow the patient.”

The Committee consisted of the following individuals: William B. Rafferty, O.D. (Board representative), Ania M. Hamp, O.D. and John D.Miller, O.D. The committee’s primary charge was to review the appropriate use of ultrasonography relative to monitoring choroidal nevi. The Committee Members were asked to review the issue and do any research necessary to render an opinion prior to the Committee’s meeting in July 2012. The Committee exchanged emails (below) and then met during the time of the NC Board Licensing Examinations in Raleigh in July, 2012.

The committee felt there was a direct and indirect issue generated as a result of this inquiry. The following are the issues and the committee’s opinions:

1) Direct issue: Is ocular ultrasonography (A or B Scan) a procedure when used for diagnostic purposes involving the eye or ocular adnexa within the scope of practice of a North Carolina licensed optometrist? This would include evaluating and monitoring choroidal nevi as well as a myriad of other indications.

The Committee felt this was not a debatable issue. Ultrasound is a diagnostic imaging procedure clearly within the scope of practice of a North Carolina licensed optometrist as defined in Section 90-114 of Article 6 of Chapter 90 of the North Carolina General Statutes.

2) Indirect issue and the issue the Committee spent the most time discussing:What is the standard of care regarding monitoring a choroidal nevus? What are the indications for monitoring a lesion using ultrasound (A and/or B scans)?

• The first question: Does every choroidal nevus need to be evaluated by ultrasound? The Committee unanimously agreed, NO! A small, flat and uniform appearing lesion, showing no suspicious changes in color, pigmentation, etc., needs only to be identified and followed on a periodic basis. Lesions of this nature are classified as “non suspicious.” Color retinal photography would be the best way to monitor a lesion taking an initial photograph to establish a baseline and following periodically for any change.

• When would ultrasound be indicated as a diagnostic tool? The Committee again unanimously agreed any deviation from the above, including change from one visit to another, would be justification. The strongest indicator for progression of a “suspicious” lesion is elevation or thickness of a lesion. 1-3

• Is there an indication for both A and B-scan ultrasonography? The B-scan is the unquestionable standard. There was evidence that A-Scan or superimposed A-Scan is appropriate when the lesion shows elevation (thickness of >1 mm) which would then be classified as a “suspicious” lesion.

• When should a choroidal nevus be referred to an ocular oncologist or similarly trained practitioner? Again, the Committee agreed that none of us would monitor a lesion showing any of the signs or symptoms below.

Malignant Transformation Risk factors for malignant transformation of choroidal nevi include:

• Thickness > 2mm.

• Subretinal fluid.

• Presence of symptoms

• Prominent orange pigment overlying the lesion.

• Location < 3mm from the optic disc.

*If two or more factors are present, the lesion is likely a choroidal melanoma.

3) The final issue the Committee was asked to consider was if the inquiry by the optometrist regarding his/her Medicare denial enough justification to investigate the optometrist for appropriate management? Issues to consider would be over utilization of ultrasound for “non suspicious” lesions, appropriate documentation of records and appropriate referral of “suspicious” lesions. The Committee not knowing any specifics about the optometrist, etc., chose not to render an opinion on this issue and respectfully defers this to the Board.

Reference:

1. Shields C L, Shields J A, Kiratli H. et al Risk factors for growth and metastasis of small choroidal melanocytic lesions. Ophthalmology 1995. 1021351–1361.1361.

2. Singh A D, Kalyani P, Topham A. Estimating the risk of malignant transformation of a choroidal nevus. Ophthalmology 2005. 1121784–1789.1789.

3. Shields C L, Shields J A. Clinical features of small choroidal melanoma. Curr Opin Ophthalmol 2002.13135–141.141.

Background information and individual Committee member opinions:

William B. Rafferty, O.D., Chairman

I discussed the standard of care with a fellowship trained ophthalmologist in both Retina and Ocular Oncology. He agreed that the standard of care in following a suspicious choroidal nevus would be a B-scan ultrasound. Adding an A-scan is not as accepted although not out of the question. However, if following a small, flat choroidal nevus without other clinical signs such as observation of lipofusion (as viewed using stereo ophthalmoscopy) would probably not yield any useful information and therefore probably would not be appropriate or be interpreted as the standard of care.

There are two main issues to consider. The first is, ‘to what level of progression should an optometrist follow a suspicious choroidal nevus before referring to someone with advanced training in ocular oncology’? The second is, ‘the staging of the lesion in question’? Is this a suspicious lesion with eventual concern for progression to a malignant melanoma or a benign appearing lesion with very low probability for progression? In the case in question, does this lesion have some early signs of potential progression such as some level of elevation?

If indeed this is a choroidal nevus that has certain early morphological signs including size and some elevation, then it would not be out of the question for an optometrist to evaluate the lesion using B-scan ultrasonography. An A-scan is a bit more of a stretch but not out of the question. On the other hand, if this is a small flat lesion without any other clinical signs of suspicion, the tests are probably not warranted. As suggested, an inquiry regarding the nature and/or staging of this or these lesions may be appropriate.

Ania M. Hamp, O.D.

I agree with Dr. Rafferty that following with the B-scan certainly and possibly an A-scan is not out of line but really depends on the size and shape of the choroidal lesion and some critical findings or risk factors. I have access to the B-scan where I practice and I have used it, but quite honestly for the typical flat, small choroidal nevus which does not show any abnormal vasculature I would not think to do a B-scan. If I thought there was some subretinal fluid, any elevation or change in pigmentation I would likely do the raster line on the OCT to pick that up. I’ve done that at times and think it works great, often better than detecting subclinical elevation on B-scan.

John D. Miller, O.D.

Finally chiming in here. I agree with the previous discussion. I think the issue (red flag) was probably the A-scan. The dimensions of the lesion would be a key factor in the determination of proper testing. There should be a clinical assessment of size in disc diameters, and an estimation of elevation in millimeters. For a newly discovered flat 3-4 dd lesion, I would photograph and monitor on a 3 to 6 month basis for the first year, then a B-scan if elevated or if unable to photograph due to location or media opacity. I found an article stating that A- scan is beneficial if the lesion is at least 2-3 mm elevated. I like to have retina or ocular oncology specialists look at elevated lesions or any lesion showing progression. I have ordered many B-scans with no problems with denials. I have never ordered an A-scan (although in the proper practice setting, it should be within the scope of practice of optometry).

The Report of the Investigative Committee on the use of Ultrasonography by Properly Trained and Licensed North Carolina Optometrists for Diagnostic Purposes was Accepted and Unanimously Approved by the North Carolina State Board of Optometry at its Meeting on August 25, 2012