Summary & Overview
CPT 67331: Strabismus Surgery After Eye Injury or Prior Non‑Muscle Ocular Procedure
Headline: CPT code 67331: Add-on strabismus surgery for eyes with prior injury or prior non-muscle ocular procedures
Lead: CPT code 67331 denotes an add-on surgical service for strabismus correction when prior ocular injury or earlier eye procedures (not involving extraocular muscles) increase operative complexity. The code captures the additional work and planning required to address factors such as scar tissue or altered anatomy.
CPT code 67331 matters nationally because it differentiates routine strabismus procedures from those requiring greater surgical effort due to prior trauma or non-muscle ocular operations, which can affect coding, billing, and reimbursement processes across payers. Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.
Readers will learn: the clinical context and proper use of this add-on surgical code; typical sites of service where the procedure is performed; common modifiers and billing considerations (listed separately); and how payers commonly approach coverage for add-on ophthalmologic procedures. The publication also provides benchmarks and policy context relevant to coding integrity and procedural documentation.
This summary is intended for national audiences including coding professionals, ophthalmic surgeons, and revenue cycle staff who need concise guidance on when CPT code 67331 applies and what operational factors influence its use.
Billing Code Overview
CPT code 67331 is an add-on strabismus surgery procedure performed when a patient has a prior eye injury or prior ocular procedure that did not involve the extraocular muscles. This service reflects the additional operative planning and complexity needed to perform strabismus surgery in the setting of previous trauma or procedures, such as excision of excessive scar tissue or other factors that increase surgical difficulty.
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Service type: Surgical, ophthalmologic strabismus correction as an add-on to a primary strabismus procedure
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Typical site of service: Hospital outpatient department or ambulatory surgical center; may also be performed in a physician office-based surgical suite when appropriate
Clinical & Coding Specifications
Clinical Context
A 34‑year‑old patient presents with persistent horizontal diplopia and limitation of ocular motility six months after a penetrating corneal laceration that required primary repair but did not involve the extraocular muscles. Clinical examination demonstrates a restrictive strabismus with scar tethering and significant globe misalignment. Preoperative evaluation includes a complete ophthalmic history, binocular vision assessment, ocular motility measurements, slit‑lamp and dilated fundus exam, and imaging (orbital CT or MRI) to evaluate scarring and extraocular muscle position. The surgeon documents increased operative complexity due to prior ocular trauma and adhesions.
The planned operative workflow for the add‑on strabismus procedure (67331) involves: preoperative consent and marking, general anesthesia, exploration of the ocular surface and conjunctival perimuscular tissues, careful dissection and excision of scar tissue, identification and mobilization of affected extraocular muscle(s), adjustment (recession/resection or repositioning) to restore alignment, hemostasis, and conjunctival closure. Postoperative care includes topical antibiotics and steroids, patching or eye shield, and scheduled follow‑up to monitor alignment, motility, and wound healing. This add‑on code is reported in conjunction with a primary strabismus procedure when prior ocular injury or prior non‑muscle eye surgery increases planning and surgical complexity.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 |