Ophthalmology and Optometry Coding Alert

Translate Muscular Language Into Strabismus Surgery Codes

Published on Sun Dec 01, 2002

Translating the ophthalmologist's documentation into procedure codes is often the hardest part of coding strabismus operations. Easily identify the correct codes for your next strabismus surgery claim using these quick questions.

Which muscles were operated on? To answer this question, a little anatomy will take you a long way.

"Without doubt, the more any coder knows about anatomy, the better," says Linda Abel, CPC, assistant administrator with Hauser-Ross Eye Institute in Sycamore, Ill. "However, when coding strabismus procedures, a few basic definitions and a good understanding of the rules will carry you a long way."

Mary Schwall, CPC, clinical practice specialist for the Yale School of Medicine in Connecticut, proffers a quick reference for ramping up on the extraocular anatomy: "Use the pictures in your CPT book as a guide," she suggests.

Each eye has six extraocular muscles that control the eyeball's movement and determine the eyeball's alignment, or in some cases misalignment. Strabismus surgery is the correction of misalignment with the potential restoration of quality visual activity.

The eye's two horizontal muscles are the lateral and medial rectus muscles; the vertical muscles consist of the superior and inferior rectus muscles; and the fifth and sixth muscles, the superior and inferior oblique muscles, are wrapped around the eye from top to bottom.

Strabismus surgery involves the recession the weakening of extraocular muscle(s) or resection the strengthening of extraocular muscle(s). If you know whether the muscles operated on are horizontal, vertical or oblique, you know which CPT codes you should access to report your surgical procedures 67311-67318.

"It's not so much the muscle itself, but the muscle group (i.e., horizontal, vertical and oblique)," Schwall says. If you are lucky, your physician will clearly indicate which types of muscles were involved in the surgery, she adds.

If not, Abel suggests coders "sit down with the doctor and gain a basic understanding of the muscles of the eye, connecting name and function."

For horizontal muscles, only codes 67311 and 67312 apply. 67314 and 67316 apply to surgery on the vertical muscles. And if the oblique muscles are operated on, you must identify them with procedure code 67318.

How many muscles were operated on in each eye?

The horizontal and vertical muscle codes are broken down depending on the number of muscles altered and by eye don't be surprised when your ophthalmologist reports operating on four muscles in one session!

Suppose a patient presents with esotropia, or turning in, of the left eye. The ophthalmologist resects the medial rectus muscle in the patient's left eye to correct the alignment. You would report 67311 (Strabismus surgery, recession or resection procedure; one horizontal muscle) to specify that one horizontal muscle was operated on in one eye.

In another example, suppose a patient presents with exotropia, a turning out, of her right eye. The ophthalmologist performs strabismus surgery on both the medial and lateral rectus muscles. In this situation you need to use 67312 (Strabismus surgery, recession or resection procedure; two horizontal muscles) to indicate that two horizontal muscles of the same eye were operated on.

In a more complicated scenario, an ophthalmologist performs strabismus surgery on the superior and inferior rectus muscles and the superior and inferior oblique muscles of a patient's left eye. In this case, you would report the operation on the two vertical rectus muscles and the inferior oblique muscle with 67316 (Strabismus surgery, recession or resection procedure; two or more vertical muscles [excluding superior oblique]) and 67318 (Strabismus surgery, any procedure, superior oblique muscle) with modifier -51 (Multiple procedures) appended to the code with the lower reimbursement or value.

Here the strabismus surgery codes are broken down according to type and number of muscles recessed or resected:

For one horizontal muscle, use code 67311

For two horizontal muscles, use code 67312

For one vertical muscle excluding superior oblique, use code 67314

For two or more vertical muscles excluding superior oblique, use code 67316

For the superior oblique muscle, use code 67318.

Remember that these codes are to be used when these muscles are operated on in one eye, Schwall says. The next step addresses how to handle strabismus surgery when it is performed in both eyes.

Was the same operation performed in both eyes?

Reporting bilateral strabismus surgery is not nearly as easy as it sounds unless you know the rules of modifier -50 (Bilateral procedure).

Suppose an ophthalmologist performs strabismus surgery on the superior rectus and the medial rectus muscles of the right eye and the inferior rectus muscle of the left eye. This translates to a vertical muscle operated on in both the right and left eyes (superior rectus and inferior rectus) and one horizontal muscle in the right eye. To code this scenario, you should use 67314 (Strabismus surgery, recession or resection procedure; one vertical muscle) with modifier -50 because a vertical muscle was operated on in each eye, and also code 67311-51-RT for the medial rectus muscle.

Don't be fooled into reporting 67316 (Strabismus surgery, recession or resection procedure; two vertical muscles [excluding superior oblique]) just because a total of two vertical muscles were operated on in the above example. Remember that these strabismus surgery codes are per eye, so you need the bilateral modifier appended to the code that represents the number of muscles operated on in each eye instead of a code that indicates the total number of vertical or horizontal muscles involved in the procedure.

Report the strabismus surgery codes, 67311-67318, per eye, which requires the use of the bilateral modifier, -50, or the left and right alpha-modifiers -LT and -RT, depending on the carrier, Schwall says. "This is a software issue with the individual insurance company. Some insurance systems can't process your claims correctly and reimburse you for each performed if you code properly but don't submit a claim in the payer's preferred format." Not knowing the idiosyncrasies of your different payers can cause you to lose money.

If the bilateral format is left to the discretion of the biller, you should consider billing in the manner clearest to the patient receiving the bill, Abel says. "One charge for each eye might be more easily understood than a single large charge with the -50 modifier."

The guidelines for modifier -50 (Bilateral procedure) indicate that the modifier is only appropriate if the exact procedure (same CPT-4 code) is performed on both sides of the body, or in this case, on both eyes. This modifier -50 stipulation mandates that coders carefully examine the documentation of the strabismus surgery and identify the muscles operated on in each eye. If the same muscle(s) in each eye are operated on in the same manner, modifier -50 is the correct modifier to report.

In another example, an ophthalmologist resects the lateral rectus muscle of a patient's left and the superior oblique muscle of the patient's right eye. In this case, two separate codes must be reported regardless of the fact that the patient underwent strabismus surgery on both eyes: 67311 (Strabismus surgery, recession or resection procedure; one horizontal muscle) and 67318 (Strabismus surgery, any procedure, superior oblique muscle).

List the code reimbursed at a higher rate first, as the primary procedure, with the corresponding eye modifier and then list the lesser procedure in the second position with modifier -51 and an eye modifier.

For most Medicare carriers, you will need to bill the procedure code with modifier -50 and a "1" in the units field when the documentation indicates that a true bilateral strabismus procedure was performed. However, other payers, including some Medicare carriers, may require you to use -RT and -LT, so be sure to check with your local carrier before submitting your claim.

Does the documentation reflect any surgical complications or additional pertinent information concerning the patient's history? If your answer is yes, you are about to delve into the world of strabismus surgery add-on codes.

"Add-on codes should be used whenever the operative report clearly documents the additional procedure (e.g., adjustable suture) or a complicating condition or history," Abel says. "A careful coder may be aware of a condition in the patient history that is not stated in the operative report. This fact should be called to the attention of the surgeon so that it can be edited into the operative report to allow billing."

When add-on codes are available for use with primary procedures, it does not mean your situation will necessarily require one.

According to Principles of CPT Coding, the strabismus add-on codes are at your disposal "to clarify the specific circumstances" and any additional work to be factored into the fee. Use the chart above of the criteria and corresponding codes to properly employ add-on codes:

All add-on procedures and services, those CPT codes proceeded by a "+," must be reported with another code representing the primary procedure. Add-on codes 67320-67334 should be reported in conjunction with codes 67311-67318, according to CPT guidelines. However, 67335-67340 can be reported with strabismus-surgery codes 67311-67334.

Add-on codes have an inherent reduction in value because it is clear they are billed in addition to a primary procedure. The -51 multiple-procedures modifier should never be appended to add-on codes, or the already reduced add-on code fee could be reduced by an additional 50 percent.