Ophthalmology and Optometry Coding Alert

Coders -- especially those for pediatric ophthalmologists -- know how difficult sorting out the various eye muscles involved in strabismus surgery can be. With 12 ocular muscles to keep track of, one simple coding mistake could cost your practice hundreds, unless you know the ropes.

Scenario: An ophthalmologist removes a 6.5-mm section of the lateral rectus muscle of the patient's left eye and resects the muscle to strengthen it and correct strabismus. He then repeats the procedure on the right eye, again removing 6.5 mm of the lateral rectus muscle and then resecting it. Two different codes might look correct -- but only one will bring you the reimbursement you deserve.

Be careful: Because the ophthalmologist performed a resection procedure on two horizontal muscles, 67312 (Strabismus surgery, recession or resection procedure; two horizontal muscles) may look correct, but don't fall into this trap.

The strabismus surgery codes (67311-67318) describe procedures done in one eye only. Although the surgeon did resect two muscles, they were in different eyes, so 67312 is not correct.

Instead, you should report 67311 (Strabismus surgery, recession or resection procedure; one horizontal muscle) bilaterally, says Riva Lee Asbell, ophthalmic coding and reimbursement educator and principal of Riva Lee Asbell Associates in Ft. Lauderdale, Fla., who led the "Strabismus Surgical Coding Challenges" seminar at The Coding Institute's Ophthalmology Coding and Reimbursement Conference in March. Most Medicare carriers want you to report the entire session on one line with modifier 50 (Bilateral procedure) and a "1" in the units field.

Warning: Reporting 67312 would even hurt your reimbursement in this case. In the Medicare physician fee schedule, 67311 has a "1" bilateral status indicator. That means Medicare will allow you to report bilateral services and will process them for payment, says Marvel J. Hammer, RN, CPC, CCS-P, ACS-PM, CHCO, with MJH Consulting in Denver.

If you report 67311-50 or two instances of 67311 on two lines -- for example, 67311-LT for the left eye and 67311-RT-51 (Multiple procedures) for the right -- Medicare will base payment on 150 percent of the fee schedule amount for a single code.

Medicare multiplies the facility relative value units (RVUs) for 67311 (13.72) by the conversion factor of 38.0870, arriving at $522.55. Appending modifier 50 for the bilateral procedure means that Medicare would reimburse you 150 percent of that, giving you $783.83 (unadjusted for geographical location).

Reporting 67312, however, even though the descriptor mentions "two horizontal muscles," will short-change you. With no bilateral pay adjustment, the RVUs for 67312 would only bring in $623.87.

To code strabismus surgery correctly, you also need to know when you can appropriately report strabismus surgery bilaterally.

If the ophthalmologist recesses both the lateral rectus and medial rectus muscles of the left eye, that is not a bilateral procedure. This is a case for which 67312 would be appropriate. The same rules apply for the vertical muscles (the superior rectus, inferior rectus and inferior oblique muscles).

Use these CPT codes for the following strabismus scenarios, based on which muscles the ophthalmologist worked on:

• 67311 for one horizontal muscle in one eye

• 67312 for two horizontal muscles in one eye

• 67314 for one vertical muscle in one eye

• 67316 for two or more vertical muscles in one eye

• 67318 for the superior oblique muscle in one eye.

If the ophthalmologist operates on one vertical and one horizontal muscle in one eye, however, use two codes -- 67311 and 67314 (... one vertical muscle [excluding superior oblique]).

Practice: So how would you code if your ophthalmologist operates on both horizontal muscles in the left eye but only one horizontal muscle in the right eye? Use 67312-LT (for the two muscles in the left eye) and 67311-51-RT (for the single muscle in the right eye). Reporting 67311 bilaterally for the horizontal muscles in both eyes would not be appropriate.

You should use add-on codes whenever the operative report clearly documents an additional procedure -- an adjustable suture, for instance -- or a complicating condition or history.

A careful coder may be aware of a condition in the patient history that the surgeon doesn't state in the operative report. You should call this fact to the physician's attention so that he can edit it in the operative report to allow billing.

Requirement: You must report all add-on procedures and services -- those CPT codes preceded by a "+" -- with another code representing the primary procedure.

For example, you can use +67320 (Transposition procedure [e.g., for paretic extraocular muscle], any extraocular muscle [specify] [list separately in addition to code for primary procedure]) with strabismus surgery codes 67311-67318, according to CPT guidelines.

Likewise, you can only report these codes with 67311-67318:

• +67331 -- Strabismus surgery on patient with previous eye surgery or injury that did not involve the extraocular muscles

• +67332 -- Strabismus surgery on patient with scarring of extraocular muscles or restrictive myopathy

• +67334 -- Strabismus surgery by posterior fixation suture technique, with or without muscle recession.

Don't overlook: You can report +67335 (Placement of adjustable suture[s] during strabismus surgery, including postoperative adjustment[s] of suture[s] [list separately in addition to code for specific strabismus surgery]) and +67340 (Strabismus surgery involving exploration and/or repair of detached extraocular muscle[s] [list separately in addition to code for primary procedure ]) not only with strabismus-surgery codes 67311-67318 but also with add-on codes 67320-67334.

But you must report 67320-67334 with a primary procedure code. Many trauma cases may involve multiple add-on codes -- for instance, in the case of an open globe in which the ophthalmologist would have to explore for damaged muscles and insert an adjustable suture.

Watch out: The bilateral status is different for the six strabismus add-on codes. Their bilateral status of "0" means that the 150 percent payment adjustment for bilateral procedures does not apply, Hammer says. Do not use modifiers LT/RT or 50 with these codes.