Ophthalmology and Optometry Coding Alert

Two muscles in one eye does not equal one muscle in both eyes.

So how did you do with our strabismus scenarios? Check our expert answers below.

Answer 1: B. The strabismus CPT^® codes, 67311-67318, are all inherently unilateral, meaning they were performed on one eye only. Therefore, if the ophthalmic surgeon performs the same procedure on both eyes, you would report the code bilaterally – for example, with modifier 50 (Bilateral surgery) attached – to make sure you received proper reimbursement.

CPT^® code 67311 (Strabismus surgery, recession or resection procedure; 1 horizontal muscle) describes surgery on one horizontal muscle in one eye; to report the procedure done in both eyes, report 67311-50.

Don’t miss: Even though the descriptor for CPT^® code 67312 (Strabismus surgery, recession or resection procedure; 2 horizontal muscles) mentions “2 horizontal muscles,” the code is actually meant for a procedure done on two horizontal muscles in the same eye.

Example: The ophthalmic surgeon resected both the lateral rectus and medial rectus muscles in one eye. Report a single instance of 67312. If the surgeon had resected both of those muscles in both eyes, you would report 67312 bilaterally.

Answer 2: C. As you saw in Answer 1, CPT^® code 67312 describes surgery on two horizontal muscles in the same eye – so in this scenario, you would add modifier LT (Left side) to that code to show which eye was operated on. For the superior rectus muscle (vertical muscle) surgery in the right eye, you would also report CPT^® code 67314 (Strabismus surgery, recession or resection procedure; 1 vertical muscle [excluding superior oblique]).

Note that the descriptor for 67314 specifies “excluding superior oblique.” For surgery on the superior oblique muscle – which controls downward and outward movement of the eye – report 67318 (Strabismus surgery, any procedure, superior oblique muscle).

Answer 3: D. CPT^® code 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]) is an add-on code, which describes the extra work involved in using adjustable sutures in strabismus surgery. 

The ophthalmic surgeon performs this procedure so that he can regulate the tension of the suture strings on the muscle to allow adjustment of the muscle as necessary.

Because 67335 is an add-on code, it is meant to be reported in addition to the code for the specific strabismus surgery – in this case, 67314. Because both procedures were performed on both eyes, you would append modifier 50 to distinguish this as a bilateral surgery, as well.

Answer 4: A. The ICD-10 diagnosis codes for strabismus are broken down to specify:

• Whether the condition is esotropia (convergent horizontal strabismus) or exotropia (divergent horizontal strabismus)
• Monocular or alternating condition
• Which pattern the patient displays
• Which eyes (left, right, both, or unspecified) are affected.

So in the above scenario, monocular esotropia in the right eye with a V pattern would be coded with ICD-10 code H50.031. The rest of the esotropia code series describes the other manifestations of the condition:

• H50.00 – Unspecified esotropia
• H50.011 – Monocular esotropia, right eye
• H50.012 – Monocular esotropia, left eye
• H50.021 – Monocular esotropia with A pattern, right eye
• H50.022 – Monocular esotropia with A pattern, left eye
• H50.031 – Monocular esotropia with V pattern, right eye
• H50.032 – Monocular esotropia with V pattern, left eye
• H50.041 – Monocular esotropia with other noncomitancies, right eye
• H50.042 – Monocular esotropia with other noncomitancies, left eye
• H50.05 – Alternating esotropia
• H50.06 – Alternating esotropia with A pattern
• H50.07 – Alternating esotropia with V pattern
• H50.08 – Alternating esotropia with other noncomitancies.

The exotropia codes (H50.1xx) follow a similar pattern.