Coding Ahead
CasePilot
Medical Coding Assistant
Case2Code
Search and Code Lookup Tool
CareerCenter
Medical Coding Job Board
Log in Register free account

Need help choosing the right code?

Ask CasePilot about procedures, modifiers, bundling, and coding guidance.

Try CasePilot

Official Description

Biopsy of extraocular muscle

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

An extraocular muscle biopsy is a surgical procedure that involves the removal of a small sample of tissue from one of the muscles that control eye movement. The extraocular muscles are responsible for the precise movements of the eye, allowing for proper vision and coordination. During this procedure, an ocular speculum is utilized to keep the patient's eye open, providing the surgeon with a clear view and access to the muscle. The procedure begins with incisions made through the conjunctiva, which is the thin membrane covering the eye, and the sclera, the white outer layer of the eyeball. This careful approach ensures that the muscle is adequately exposed while minimizing damage to surrounding tissues. Once the target muscle is identified, a small portion of the muscle tissue is meticulously excised. It is crucial that this sampling is performed with precision to preserve the overall function of the eye muscle, thereby preventing any adverse effects on eye movement. After the biopsy is completed, the incisions are closed, concluding the procedure.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The biopsy of an extraocular muscle is typically indicated for various clinical reasons, including:

  • Suspected Muscle Disorders The procedure may be performed when there is a suspicion of underlying muscle disorders that could affect eye movement.
  • Evaluation of Inflammatory Conditions It is indicated for assessing inflammatory conditions that may involve the extraocular muscles, such as thyroid eye disease or myositis.
  • Diagnosis of Tumors The biopsy can be necessary for diagnosing tumors or neoplasms that may be affecting the extraocular muscles.

2. Procedure

The procedure for an extraocular muscle biopsy involves several critical steps to ensure accuracy and safety:

  • Step 1: Preparation The patient is positioned comfortably, and the ocular area is prepared and sterilized to minimize the risk of infection. An ocular speculum is then placed to hold the eye open, providing the surgeon with unobstructed access to the extraocular muscles.
  • Step 2: Incision Incisions are made through the conjunctiva and sclera, which allows the surgeon to carefully expose the targeted extraocular muscle. This step requires precision to avoid damaging surrounding tissues and structures.
  • Step 3: Muscle Isolation Once the muscle is exposed, the surgeon isolates the specific muscle that requires biopsy. This careful dissection is crucial to ensure that only the necessary tissue is removed without compromising the muscle's function.
  • Step 4: Tissue Sampling A small sample of the muscle tissue is then excised. The surgeon must ensure that the sampling is done delicately to preserve the overall function of the muscle and minimize any potential complications.
  • Step 5: Closure After the biopsy is completed, the incisions are meticulously closed. This may involve suturing the conjunctiva and sclera to ensure proper healing and restore the integrity of the eye.

3. Post-Procedure

Following the extraocular muscle biopsy, patients may require specific post-procedure care to promote healing and monitor for any complications. It is common for patients to experience some discomfort or swelling in the ocular area, which can be managed with prescribed pain relief medications. Patients are typically advised to avoid strenuous activities and to follow up with their healthcare provider for monitoring. Additionally, any signs of infection, such as increased redness, discharge, or fever, should be reported immediately. The healthcare provider may schedule a follow-up appointment to assess the healing process and discuss the biopsy results.

Short Descr BIOPSY EYE MUSCLE
Medium Descr BIOPSY EXTRAOCULAR MUSCLE
Long Descr Biopsy of extraocular muscle
Status Code Active Code
Global Days 000 - Endoscopic or Minor Procedure
PC/TC Indicator (26, TC) 0 - Physician Service Code
Multiple Procedures (51) 2 - Standard payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50) 1 - 150% payment adjustment for bilateral procedures applies.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 0 - Payment restriction for assistants at surgery applies to this procedure...
Co-Surgeons (62) 0 - Co-surgeons not permitted for this procedure.
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family 99 - Concept Does Not Apply
APC Status Indicator Hospital Part B services paid through a comprehensive APC
ASC Payment Indicator Surgical procedure on ASC list in CY 2007; payment based on OPPS relative payment weight.
Type of Service (TOS) 2 - Surgery
Berenson-Eggers TOS (BETOS) P4E - Eye procedure - other
MUE 1
CCS Clinical Classification 18 - Diagnostic procedures on eye
50 Bilateral procedure: unless otherwise identified in the listings, bilateral procedures that are performed at the same session, should be identified by adding modifier 50 to the appropriate 5 digit code. note: this modifier should not be appended to designated "add-on" codes (see appendix d).
51 Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d).
58 Staged or related procedure or service by the same physician or other qualified health care professional during the postoperative period: it may be necessary to indicate that the performance of a procedure or service during the postoperative period was: (a) planned or anticipated (staged); (b) more extensive than the original procedure; or (c) for therapy following a surgical procedure. this circumstance may be reported by adding modifier 58 to the staged or related procedure. note: for treatment of a problem that requires a return to the operating/procedure room (eg, unanticipated clinical condition), see modifier 78.
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
79 Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.)
82 Assistant surgeon (when qualified resident surgeon not available): the unavailability of a qualified resident surgeon is a prerequisite for use of modifier 82 appended to the usual procedure code number(s).
GC This service has been performed in part by a resident under the direction of a teaching physician
LT Left side (used to identify procedures performed on the left side of the body)
RT Right side (used to identify procedures performed on the right side of the body)
Date
Action
Notes
2011-01-01 Changed Short description changed.
2007-01-01 Added First appearance in code book in 2007.
Code
Description
Code
Description
Code
Description
Code
Description
Code
Description
CasePilot

Get instant expert-level medical coding assistance.

Ask about:
CPT Codes Guidelines Modifiers Crosswalks NCCI Edits Compliance Medicare Coverage
Example: "What is CPT code 99213?" or "Guidelines for E/M services"