Coding for Ophthalmic Radiology Services: Part 2—A-Scan

This article is from March 2005 and may contain outdated material.

Confusion still persists over how to code for an A-scan (CPT code 76519) or an IOLMaster (CPT code 92136) service. Both tests are used prior to cataract surgery to help determine the axial length of the eye. This measurement is then used to calculate the dioptric strength of the IOL. This month we’ll explain use of the A-scan; next month the IOLMaster.

Billing for the A-Scan

When billing for an A-scan, use CPT code 76519 Ophthalmic biometry by ultrasound echography, A-scan: with intraocular lens power calculation.

Most radiological tests are split between a technical and a professional component. The technical component represents performance of the test, equipment used and cost of supplies. The professional component represents the physician’s interpretation of the test results.

Billing for A-scan is unusual because the two components have different billing assignments. The technical component is considered a bilateral procedure, while the professional component is considered unilateral. (This is also true when billing for an IOLMaster service.)

Suppose, for instance, that an A-scan is performed on both eyes and surgery is scheduled first for the left eye and then, a month later, for the right eye.

For the first (left) eye, code 76519–LT. Payment is for the technical component of both eyes, and the professional component of the surgical (left) eye.

For the second (right) eye, you only can bill for the professional component of the A-scan. This is done by appending modifier 26 to the A-scan code: 76519–26–RT.  

Whether you are billing for A-scan or IOLMaster, the ordering physician’s UPIN is required on the claim.

The codes are bundled in the CCI. Only payment for one is allowed.

Please check your Local Carrier Determination policy for state-specific requirements. For non-Medicare payers who do not recognize –TC (technical component) and –26 (professional component) modifiers, simply code 76519–eye modifier or 92136–eye modifier.

An ABC of the A-Scan

For billing staff who want a greater understanding of how A-scans work, here’s a quick summary of the underlying ultrasound technology. Ultrasound is a medical imaging technique that uses high-frequency sound waves and their echoes. In ultrasound, the following events happen:

1. The ultrasound machine uses a probe to transmit high-frequency (1 to 5 megahertz) sound pulses into your body.
2. The sound waves travel into your body and hit a boundary between tissues (e.g., between fluid and soft tissue or between soft tissue and bone).
3. Some of the sound waves get reflected back to the probe, while some travel on farther until they reach another boundary and get reflected.
4. The reflected waves are picked up by the probe and relayed to the machine.
5. The machine calculates the distance from the probe to the tissue or organ (boundaries) using the speed of sound in tissue (5,005 feet/second or 1,540 meters/second) and the time of each echo’s return (usually on the order of millionths of a second).
6. The machine displays the distances and intensities of the echoes on the screen, forming a two-dimensional image.

An A-scan is a one-dimensional display of sound waves. Each time a sound wave hits a structure in the eye, a spike is formed on the examiner’s screen. The height and spacing between each of the echoes provides the examiner with information that can be used when calculating the power of the IOL.