66761

👩🏾‍⚕️CPT Code 66761: Documentation & Billing Guide

Iridotomy/Iridectomy, Peripheral (Including Transfixion); for Glaucoma, with Operating Microscope

Last Updated: February 2026
Status: 2025 Medicare Fee Schedule Compliant
Specialty Tags:ophthalmology CPT glaucoma medterm ophthalmology diagnostic ophthalmology medical_coding

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QUICK REFERENCE

Element	Details
Code	66761
Code Type	Surgical Procedure - Ophthalmology
Procedure Type	Peripheral iridotomy/Iridectomy for glaucoma using operating microscope
Global Period	010 days (minor surgical procedure)
Work RVU (2025)	3.92 RVU
Practice Expense RVU (2025, Non-Facility)	2.17 RVU
Practice Expense RVU (2025, Facility)	1.12 RVU
Malpractice RVU (2025)	0.33 RVU
Total RVU (2025, Non-Facility)	6.42 RVU
Total RVU (2025, Facility)	5.37 RVU
2025 Medicare Fee (Non-Facility)	~$207.78(6.42RVU\times$32.3465 CF × GPCI)
2025 Medicare Fee (Facility)	~$173.82(5.37RVU\times$32.3465 CF × GPCI)
Conversion Factor (2025)	$32.3465
Estimated Commercial Insurance	$500 - 1,500
Global Period Includes	Pre-operative visit, procedure, post-operative visits (10 days)
Common Place of Service	Hospital outpatient (22), ASC (24), office surgery center (11)
Specialty	Ophthalmology, Glaucoma Specialist
Procedure Time	15-30 minutes

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📋SHORT DEFINITION

CPT 66761 describes a peripheral iridotomy or iridectomy (surgical removal of iris tissue) performed with an operating microscope for the treatment of angle-closure glaucoma. This procedure involves creating an opening in the peripheral iris to allow aqueous humor to flow around the iris and behind the lens, relieving intraocular pressure in angle-closure mechanisms. The operating microscope provides magnification for precise surgical control.

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LONG DEFINITION

CPT 66761 represents a microsurgical iris procedure used to treat or prevent angle-closure glaucoma by creating a patent opening between the anterior and posterior chambers of the eye.

Angle-Closure Glaucoma: Why Iridotomy Matters

Angle-Closure Mechanism:

• In angle-closure glaucoma, the iris is pushed forward against the cornea, blocking the drainage angle
• This blockage prevents aqueous humor from draining, causing elevated intraocular pressure (IOP)
• Elevated IOP damages the optic nerve and causes vision loss

How Iridotomy Works:

• Creates an opening (hole) in the peripheral iris
• Allows aqueous humor to bypass the lens and flow directly from posterior to anterior chamber
• Relieves forward bowing of iris
• Opens the drainage angle and restores aqueous humor outflow
• Reduces IOP and prevents further optic nerve damage

Why Operating Microscope:

• Magnification allows precise tissue placement and cutting
• Better visualization of iris anatomy and anterior chamber
• Reduces trauma to surrounding tissues
• Enables precise size and location control of iridotomy
• Essential for safe peripheral iris surgery

Clinical Indications for 66761

Acute Angle-Closure Glaucoma:

• Acute angle closure with elevated IOP (emergency situation)
• Requires rapid IOP reduction to prevent permanent vision loss
• Iridotomy definitive treatment after emergency IOP management

Subacute or Chronic Angle-Closure Glaucoma:

• Intermittent angle-closure episodes
• Chronic partial angle closure with elevated IOP
• Progressive optic nerve damage despite other treatments

Narrow Angles (Anatomically Predisposed):

• Anatomically narrow angles at risk for angle closure
• Fellow eye of patient with angle-closure glaucoma (prophylactic)
• Prevention of angle-closure glaucoma in at-risk patients

Secondary Angle-Closure Mechanisms:

• Angle closure from iris bowing (malignant glaucoma)
• Phacomorphic angle closure (lens-related)
• Angle closure from iris neovascularization
• Aqueous misdirection/malignant glaucoma

Other Indications:

• Iridectomy for iris lesion
• Iris tissue removal for pupillary membrane management
• As adjunctive procedure during other eye surgery

Procedure Technique

Pre-Operative Assessment:

• Gonioscopy to assess anterior chamber angle
• IOP measurement (Goldmann applanation tonometry, other methods)
• Optic nerve evaluation
• Fellow eye assessment
• Risk stratification for angle-closure risk

Microscopic Iridotomy/Iridectomy:

• Patient positioned supine under operating microscope
• Topical anesthesia applied to eye (proparacaine, lidocaine)
• Eyelid speculum inserted to hold eyelids open
• Surgical microscope focused on iris
• Surgical approach:
  • Transfixion approach (most common): Needle or laser creates small opening, then iris is lifted through needle, and iris tissue is excised with scissors or forceps
  • Direct approach: Small incision in peripheral cornea, iris tissue grasped and excised directly
• Entry site typically at 10-12 o’clock position (superior iris)
• Iris opening typically 1-2mm diameter
• Hemostasis achieved (usually self-limited bleeding; may use cautery if needed)
• Anterior chamber may be reformed with balanced salt solution (BSS) if needed
• Incision closed (if corneal incision) with sutures or self-sealing

Verification:

• Patent iridotomy confirmed: aqueous flow visible through opening
• Gonioscopy performed post-operatively to confirm angle opening
• IOP monitoring post-operative

Procedure Duration: Typically 15-30 minutes

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Key Distinctions

Code	Description	Method	RVU (Work)	Global
66761	Iridotomy/iridectomy for glaucoma, with operating microscope	Surgical microscope	3.92	010
66762	Iridotomy/iridectomy for glaucoma, without operating microscope	Manual/loupes	3.28	010
65765	Iridectomy, surgical (non-glaucoma indication)	Surgical microscope	3.47	010
66770	Closure of cyclodialysis (different procedure)	N/A	4.20	010
66835	trabeculectomy/glaucoma (different procedure)	Surgical microscope	6.07	090

Critical Distinctions:

• 66761 vs. 66762 - Both are iridotomy for glaucoma. 66761 uses operating microscope (higher RVU 3.92). 66762 is without operating microscope (lower RVU 3.28). If you used microscope, code 66761. If not, use 66762.
• 66761 vs. 65765 - 66761 is iridotomy/iridectomy for glaucoma treatment. 65765 is iridectomy for other indications (iris lesion, pupillary membrane, etc.). Diagnosis code must support angle-closure glaucoma for 66761.
• 66761 vs. 66835 - 66761 is iridotomy (10-day global). 66835 is trabeculectomy (90-day global). Different procedures with different RVUs and global periods.

Important Note:

The use of operating microscope is the key differentiator between 66761 (with microscope) and 66762 (without). Documentation must verify that operating microscope was used.

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WORK RELATIVE VALUE UNITS (wRVUs) & COMPONENTS

Work RVU Breakdown (2025)

RVU Component	Value	What It Represents
Work RVU	3.92	Physician work, surgical skill, decision-making, technical complexity
Practice Expense RVU (non-facility)	2.17	Operating microscope, surgical instruments, surgical supplies, staff support
Practice Expense RVU (facility)	1.12	Lower due to hospital/ASC equipment overhead
Malpractice RVU	0.33	Malpractice insurance and liability (minor surgical procedure but intraocular)
TOTAL RVU (non-facility)	6.42	Total relative value units
TOTAL RVU (facility)	5.37	Total relative value units (lower)

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RVU Conversion to Dollar Amount (2025)

Formula: RVU × Conversion Factor (CF) × Geographic Practice Cost Index (GPCI) = Payment

2025 Medicare Conversion Factor: $32.3465

Typical Calculations (Non-Facility, GPCI = 1.0):

• 3.92 wRVU × $32.3465=\ast \ast$126.88** (work component)
• 2.17 PE RVU × $32.3465=\ast \ast$70.23** (practice expense)
• 0.33 MP RVU × $32.3465=\ast \ast$10.67** (malpractice)
• Total = ~$207.78 per procedure (non-facility, GPCI 1.0)

Facility-Based (Hospital/ASC):

• 3.92 wRVU × $32.3465=\ast \ast$126.88** (work component, same)
• 1.12 PE RVU × $32.3465=\ast \ast$36.23** (practice expense, lower)
• 0.33 MP RVU × $32.3465=\ast \ast$10.67** (malpractice, same)
• Total = ~$173.82 per procedure (facility, GPCI 1.0)

Real-World Range (2025):

• Non-Facility (office surgery center): $190-$240
• Facility-Based (hospital OR, ASC): $160-$200

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GLOBAL PERIOD

Global Period Status: 010 days (10-Day Global)

What This Means:

• CPT 66761 has a 10-day global period
• Includes: Pre-operative visit, procedure, post-operative visits for 10 days
• One flat fee covers all bundled services
• No additional payment for routine post-operative complication management during 10 days
• Separate payment only for unrelated E/M services (use modifier -24)

Billing Implications:

• Cannot bill separate E/M codes within 10 days for eye-related care (routine post-op visits, follow-up IOP checks)
• CAN bill separate E/M code for unrelated problems with modifier -24 (e.g., patient has post-operative visit AND unrelated infection)
• Same-day E/M + 66761 can be billed together with modifier -25 on E/M if separately identifiable
• Post-operative complications managed within global period are included; separate charge only if requiring return to OR

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DOCUMENTATION REQUIREMENTS FOR 66761

Minimum Documentation Components

Pre-Operative Assessment:

Chief Complaint/Indication:

• angle-closure glaucoma (acute, subacute, or chronic)
• Narrow angles (prophylactic iridotomy)
• Fellow eye of patient with angle closure
• Elevated IOP due to angle-closure mechanism
• Previous angle-closure episode

History of Present Illness:

• Duration of glaucoma or angle-closure symptoms
• Acute episode symptoms (eye pain, blurred vision, halos, red eye) if applicable
• Prior treatments (medications, laser procedures, etc.)
• Prior IOP readings and trend
• Symptoms of vision loss
• Risk factors for angle closure (hyperopia, anterior lens position, family history)

Ophthalmologic Examination:

• gonioscopy findings - CRITICAL:
  • Anterior chamber angle configuration
  • Angle width measurement (e.g., Shaffer grading: 0=closed, 1=slit, 2=narrow, 3=moderate, 4=wide)
  • Trabecular meshwork visibility
  • Angle pigmentation
  • Peripheral iris configuration (bowed forward or not)
• IOP measurement: Current IOP; comparison to baseline; IOP trend
• Slit-lamp examination:
  • Iris appearance
  • Lens position
  • Anterior chamber depth
  • Any iris lesions
  • Corneal clarity
• Optic nerve assessment:
  • Cup-to-disc ratio
  • Optic nerve appearance
  • Evidence of glaucomatous changes
• Visual acuity: Current VA; comparison to baseline
• Visual field: If recent VF available, comparison noted

Informed Consent:

• Risks: Corneal abrasion, hyphema (blood in anterior chamber), cataract formation, iris sphincter muscle damage, failure to open angle, need for repeat procedure, infection
• Benefits: IOP reduction, angle opening, prevention of acute angle closure, prevention of vision loss
• Alternatives: Medical management alone, laser peripheral iridotomy, other procedures

Baseline Photographs:

• Anterior segment photographs (if available); iris appearance documented

Imaging:

• Gonioscopy findings documented
• Anterior chamber optical coherence tomography (ASOCT) or ultrasound biomicroscopy (UBM) findings if available

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Surgical Procedure Documentation:

Operative Technique:

• Patient positioning: Supine under operating microscope
• Anesthesia: Topical anesthesia (proparacaine, lidocaine); infiltration anesthesia if needed
• Surgical approach: Transfixion approach vs. direct approach (specify)
• Entry site: Location on iris (e.g., “superior iris at 12 o’clock position”)
• Surgical instruments used: Specific instruments for iridotomy/iridectomy
• Iris manipulation: How iris tissue was grasped and removed; amount of tissue removed
• Iridotomy characteristics:
  • Size of opening (approximately mm)
  • Location on iris
  • Configuration (round, oval, irregular)
• Hemostasis: Bleeding control method (usually self-limited; cautery if needed)
• Anterior chamber management: Whether anterior chamber reformed with BSS
• Incision closure: If corneal incision, closure method and suture material
• Post-operative gonioscopy: Confirmation that angle opened; aqueous flow through iridotomy visible
• IOP post-operative: IOP measured at end of procedure (if possible)
• Intraoperative complications: None vs. specific issues (corneal abrasion, hyphema, iris prolapse, etc.)

Documentation Details - CRITICAL:

• Operating microscope used (verification that 66761 appropriate vs. 66762)
• Magnification level if documented
• Iris tissue excised (iridectomy) vs. just opening created (iridotomy)
• Degree of tissue removal documented

Post-Operative Plan:

• Medications: Post-operative eye drops (antibiotics, steroids, IOP-lowering drops)
• Activity restrictions: Eye protection, avoid rubbing, water precautions
• Follow-up schedule: When to return for post-op checks
• Post-operative monitoring: IOP checks scheduled, gonioscopy follow-up, visual field follow-up
• Complications to report: Increasing pain, vision loss, persistent bleeding, infection signs

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Post-Operative Notes (Included in Global Period):

• IOP: Post-operative IOP readings at follow-up visits
• Anterior chamber: Clarity, hyphema status (if present)
• Angle status: gonioscopy confirmation that angle remains open
• Iridotomy patency: Confirmation that iridotomy remains patent (not closed)
• Visual acuity: Post-operative VA
• Complications: Infection, excessive bleeding, corneal edema, cataract changes, etc.
• Treatment response: IOP reduction achieved; symptoms improvement

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BILLING RULES & MODIFIERS

Global Period Coverage

What’s Included in 66761: ✓ Pre-operative assessment ✓ The surgical iridotomy/iridectomy procedure with operating microscope ✓ Post-operative visits within 10 days (routine follow-up, IOP checks) ✓ Routine post-operative complication management

✗ NOT Included (Can bill separately):

• Unrelated E/M during 10-day period (use modifier -24)
• Separately identifiable E/M same day (use modifier -25 on E/M)
• Return to OR for complication management (some scenarios; verify payer)

Common Modifiers

Modifier	Description	When to Use
-25	Significant, separately identifiable E/M	When both E/M and surgery performed same day; apply to E/M
-24	Unrelated E/M during postoperative period	When billing E/M for unrelated issue during 10 days
-LT/-RT	Left/Right eye	If unilateral procedure (apply to 66761)
-50	Bilateral procedure	If bilateral iridotomies performed same day (rare)
-76	Repeat by same physician	If same eye requires repeat procedure within 10 days
-77	Repeat by different physician	If different physician performs repeat procedure
None (most common)	Standard billing	Routine unilateral iridotomy

Modifier -LT/-RT Usage (Common):

• Most iridotomies are unilateral
• Apply -LT (left) or -RT (right) to specify eye
• Example: 66761-RT (right eye iridotomy)

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MEDICARE RULES FOR 66761

CMS-Specific Rules & Policies

1. Global Period Management

• 10-day global period for iridotomy
• All routine post-op care included; no separate billing
• Unrelated services must use modifier -24

2. Facility vs. Non-Facility Billing

• Non-Facility (office surgery center): Higher PE RVU (2.17), higher reimbursement (~$208)
• Facility (hospital OR, ASC): Lower PE RVU (1.12), lower reimbursement (~$174)
• Hospital facility charges billed separately

3. Operating Microscope Use (CRITICAL)

• Code 66761 requires operating microscope use
• If operating microscope NOT used, code 66762 instead (lower RVU 3.28)
• Documentation must verify microscope was used
• If billed as 66761 without microscope, susceptible to downcode audit

4. Bilateral Procedures

• If bilateral iridotomies same day, use modifier -50
• Or bill each eye separately with -LT and -RT
• Most insurers pay both eyes; some may reduce second eye payment
• Check payer policy

5. Laser vs. Surgical Iridotomy

• CPT 66761 is SURGICAL iridotomy (with microscope)
• Laser peripheral iridotomy has different CPT code (65855)
• Do NOT confuse codes; laser and surgical iridotomy are different procedures
• Most angle-closure glaucoma treated with laser iridotomy initially; 66761 typically for failed laser or surgical approach needed

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LOCAL COVERAGE DETERMINATIONS (LCDs) & NATIONAL COVERAGE

National Coverage Determination (NCD)

There is NO specific NCD for CPT 66761 (surgical iridotomy).

General Medicare Coverage Policy:

• iridotomy/iridectomy covered when medically necessary to treat angle-closure glaucoma
• Must have documented angle-closure glaucoma diagnosis
• Typically covered after failed laser iridotomy or when surgical approach indicated

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Local Coverage Determinations (LCDs) - MAC-Specific

LCDs vary by Medicare Administrative Contractor (MAC) jurisdiction.

Common LCD Requirements for Glaucoma Surgery:

Requirement	Details
Medical Necessity	Documented angle-closure glaucoma, elevated IOP, narrow angles at risk
Documentation	Gonioscopy findings, IOP measurements, optic nerve assessment
Diagnosis Code	ICD-10 showing angle-closure glaucoma (H40.2x)
Prior Treatment	Typically requires documentation of prior medical therapy or laser attempt
Eye Specification	Right vs. left eye must be documented

To Find Your MAC’s LCD:

1. Go to CMS LCD Search Tool: https://www.cms.gov/cclc/lcd
2. Enter your MAC jurisdiction
3. Search for “glaucoma,” “iridotomy,” or “angle-closure”
4. Review specific coverage criteria and documentation requirements

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2025 REIMBURSEMENT INFORMATION

Medicare 2025 Fee Schedule

CPT 66761 - Iridotomy/Iridectomy for Glaucoma, with Operating Microscope

Category	Value
Work RVU	3.92
Practice Expense RVU (non-facility)	2.17
Practice Expense RVU (facility)	1.12
Malpractice RVU	0.33
Total RVU (non-facility)	6.42
Total RVU (facility)	5.37
Conversion Factor (2025)	$32.3465
National Average Fee (Non-Facility, GPCI 1.0)	$207.78
Estimated Range (Non-Facility)	$190 - 240
National Average Fee (Facility, GPCI 1.0)	$173.82
Estimated Range (Facility)	$160 - 200

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Year-Over-Year Comparison (2024 vs 2025)

Metric	2024	2025	Change
Work RVU	3.92	3.92	—
PE RVU (non-facility)	2.17	2.17	—
CF	$33.2875	$32.3465	-2.8%
National Average (Non-Facility)	~$214.05	~$207.78	-2.8%

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Commercial Insurance & Medicaid Reimbursement (2025)

Commercial Insurance:

• Typically pays 2-3× Medicare rates
• Estimated 66761 payment: $500-$1,500 (varies by payer)
• Most insurers cover iridotomy when medically necessary
• Some payers may require prior authorization

Medicaid:

• Varies significantly by state
• Estimated 66761 payment: $150-$400 (state-dependent)
• Most states cover iridotomy for angle-closure glaucoma
• Prior authorization may be required

Self-Pay/Cash Price:

• Typically $300-$800 (lower than major glaucoma surgery)

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COMPARISON TO RELATED CODES

Glaucoma Surgical Procedure Codes

Code	Description	RVU (Work)	Global
66761	Iridotomy/iridectomy for glaucoma, WITH microscope	3.92	010
66762	Iridotomy/iridectomy for glaucoma, WITHOUT microscope	3.28	010
65855	Laser peripheral iridotomy	0.75	000
65765	Iridectomy, surgical (non-glaucoma)	3.47	010
66835	trabeculectomy (major glaucoma surgery)	6.07	090
66840	Trabeculotomy	4.67	010

Key Comparisons:

• 66761 vs. 66762 - Same procedure, different approach. 66761 uses operating microscope (3.92 RVU). 66762 without microscope (3.28 RVU). Documentation critical.
• 66761 vs. 65855 - 66761 is surgical iridotomy (3.92 RVU, 10-day global). 65855 is laser iridotomy (0.75 RVU, 0-day global). Completely different procedures.
• 66761 vs. 66835 - 66761 is iridotomy (3.92 RVU, 10-day). 66835 is trabeculectomy (6.07 RVU, 90-day). Major vs. minor glaucoma surgery.

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FREQUENTLY BILLED SCENARIOS FOR 66761

Scenario 1: Acute Angle-Closure Glaucoma

Patient: 68-year-old presents with acute angle-closure glaucoma (right eye)

Clinical Assessment:

• Chief complaint: Acute right eye pain, blurred vision, halos around lights
• IOP: Right eye 52 mmHg (severely elevated), left eye 15 mmHg
• Gonioscopy: Right eye angle closed (Shaffer grade 0-1), left eye narrow (Shaffer grade 2)
• Optic nerve: Right optic nerve cupping present (chronic angle closure); glaucomatous changes
• Prior medical management: Failed to lower IOP (emergency laser attempted but unsuccessful)
• Decision: Surgical iridotomy indicated

Procedure:

• Right eye surgical iridotomy under operating microscope
• Transfixion approach; superior iris at 12 o’clock position
• Peripheral iris tissue excised (iridectomy)
• Patent iridotomy confirmed; aqueous flow visible
• Post-operative IOP: 28 mmHg (initial reduction, further management planned)
• Operating microscope used throughout procedure

Coding:

• 66761-RT (iridotomy for angle-closure glaucoma, right eye, with operating microscope)
• Diagnosis: H40.2214 (unspecified angle-closure glaucoma with macular hypoplasia, right eye, indeterminate stage), H40.10X4 (open-angle glaucoma with macular hypoplasia, indeterminate stage)

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Scenario 2: Prophylactic Iridotomy (Fellow Eye)

Patient: 62-year-old with history of angle-closure glaucoma in right eye (treated with laser iridotomy); now prophylactic surgery being performed on left eye

Clinical Assessment:

• Right eye: Prior laser peripheral iridotomy 2 years ago; stable IOP
• Left eye: Anatomically narrow angles on gonioscopy (Shaffer grade 1-2), no prior episodes
• Risk factors: Hyperopia, anterior lens position predisposing to angle closure
• Decision: Prophylactic surgical iridotomy indicated for left eye to prevent angle-closure episode

Procedure:

• Left eye surgical iridotomy under operating microscope
• Direct approach; peripheral iris excised
• Angle opened and patent confirmed
• Operating microscope magnification verified procedural precision

Coding:

• 66761-LT (prophylactic iridotomy for narrow angles, left eye)
• Diagnosis: H40.033 (unspecified angle-closure glaucoma with macular hypoplasia, bilateral)

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Scenario 3: Bilateral Iridotomies (Same Session)

Patient: 55-year-old with bilateral angle-closure glaucoma

Procedure:

• Right eye iridotomy performed first; confirmed patent
• Left eye iridotomy performed second; confirmed patent
• Both eyes treated with operating microscope

Coding:

• 66761-50 (bilateral iridotomies)
• OR bill separately: 66761-RT + 66761-LT
• Verify payer policy on bilateral procedure payment

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DOCUMENTATION TIPS FOR 66761

What to Document

✓ SHOULD INCLUDE:

1. Angle-Closure Diagnosis - Acute, subacute, chronic, or prophylactic iridotomy indicated
2. Gonioscopy Findings - CRITICAL:
   • Anterior chamber angle width (Shaffer grading or description)
   • Angle configuration
   • Trabecular meshwork visibility
3. IOP Measurement - Current IOP, pre-operative and post-operative
4. Optic Nerve Assessment - Cup-to-disc ratio, glaucomatous changes
5. Iris Appearance - At baseline and intraoperatively
6. Surgical Approach - Transfixion vs. direct approach specified
7. Operating Microscope Use - CRITICAL:
   • Documented that operating microscope was used
   • Magnification level if documented
   • Important for 66761 vs. 66762 differentiation
8. Iridotomy Characteristics:
   • Size of opening (mm)
   • Location on iris (e.g., “superior at 12 o’clock”)
   • Configuration (round, oval)
9. Iris Tissue Removal - Amount of iris excised (iridectomy vs. just opening)
10. Hemostasis - Method and result
11. Post-operative Angle Status - Gonioscopy confirmation angle opened
12. Iridotomy Patency - Confirmed that opening patent and aqueous flowing
13. Anterior Chamber - Clarity, any blood/hyphema
14. Post-operative IOP - Measured at end of procedure if possible
15. Intraoperative Complications - None or specific issues
16. Eye Identification - Right (-RT) or left (-LT) clearly documented
17. Post-operative Plan - Follow-up schedule, medications, monitoring

✗ SHOULD AVOID:

• No documentation that operating microscope was used (risk downcode to 66762)
• Vague angle assessment (no gonioscopy findings documented)
• No confirmation that angle opened post-operative
• No IOP documentation
• No mention of iris tissue removal (vague surgical description)
• Copy-paste documentation without case-specific details
• Ambiguity about which eye treated (right vs. left)

Sample Documentation Template

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OPERATIVE REPORT - Surgical Iridotomy for Angle-Closure Glaucoma (CPT 66761)

PATIENT: [Name]
DATE: [Date]
SURGEON: [Name, Credentials]
EYE: Right / Left ANESTHESIA: Topical anesthesia [proparacaine / lidocaine]; local infiltration [if used]

INDICATION: [Age]-year-old patient with [acute / subacute / chronic / prophylactic] angle-closure glaucoma of the [right / left] eye for surgical iridotomy.

PRE-OPERATIVE FINDINGS:

Ocular Assessment:

• Intraocular Pressure (IOP): [Right X mmHg / Left X mmHg] (date of measurement)
• Anterior Chamber Angle (Gonioscopy):
  • [Right / Left] eye: Shaffer grade [X] (closed / very narrow / narrow / moderate / wide)
  • Angle configuration: [Description; iris bowed, peripheral iris touching trabecular meshwork, etc.]
  • Trabecular meshwork visibility: [Grade or description]
• Optic Nerve Assessment:
  • Cup-to-disc ratio: [X]
  • Glaucomatous changes: [Present / absent]
• Iris appearance: [Normal / edematous / traumatic mydriasis / other findings]
• Visual acuity: [VA]

PRE-OPERATIVE IMAGING: [If available: Gonioscopic findings, ASOCT findings, UBM findings]

PROCEDURE:

Surgical Technique: Patient positioned supine under [OPERATING MICROSCOPE]. Topical anesthesia applied. Eyelid speculum inserted.

Approach: [Transfixion approach / direct approach]

Surgical Method: Using transfixion approach [or specify]:

• Peripheral iris grasped and positioned for iridotomy
• Peripheral iris tissue excised with [scissors / forceps / other]
• Iridotomy created at [location: superior, 12 o’clock position]
• Iridotomy size: Approximately [X] mm
• Iris tissue removed: [Amount described]
• Hemostasis: Achieved with [pressure / cautery / spontaneous / other]

OPERATING MICROSCOPE: Operating microscope used throughout procedure at [magnification level if documented]. Provides excellent visualization and precise tissue control.

Post-Operative Inspection:

• Anterior chamber: Clear / hyphema (amount) / other findings
• Iridotomy patency: CONFIRMED patent; aqueous humor flow visible through iridotomy
• Angle status: POST-OPERATIVE GONIOSCOPY: Angle opened [specify Shaffer grade if performed]; trabecular meshwork now visible
• Iris appearance: [Post-operative assessment]

INTRAOPERATIVE COMPLICATIONS: None

INTRAOPERATIVE IOP: [If measured: X mmHg at end of procedure]

ASSESSMENT: Successful surgical iridotomy of [right / left] eye for [acute / chronic] angle-closure glaucoma. Iridotomy patent and angle opened. Patent aqueous flow confirmed.

POST-OPERATIVE PLAN:

1. Medications: [Antibiotic drops, steroid drops, IOP-lowering drops as indicated]
2. Activity: Eye rest, eye protection, no rubbing
3. Follow-up: Post-operative exam [timeframe]; IOP checks; gonioscopy follow-up
4. Monitoring: Iridotomy patency, IOP trend, angle status, vision

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AUDIT DEFENSE CHECKLIST FOR 66761

Before billing 66761, verify:

• Operating microscope used and documented - NOT just loupe magnification; this differentiates 66761 from 66762
• Angle-closure glaucoma documented - Gonioscopy findings confirming angle-closure mechanism
• Gonioscopy findings documented - Anterior chamber angle width and configuration (Shaffer grade or description)
• IOP documented - Pre-operative and post-operative measurements
• Optic nerve assessment documented - Cup-to-disc ratio and glaucomatous changes
• Surgical approach documented - Transfixion or direct approach specified
• Iris tissue removal documented - Iridectomy (tissue excised) vs. just iridotomy (opening created)
• Iridotomy characteristics documented - Size, location, configuration
• Post-operative angle status documented - Gonioscopy confirmation that angle opened
• Iridotomy patency confirmed - Opening patent and aqueous flowing post-operatively
• Eye identification documented - Right or left eye clearly specified
• Intraoperative complications documented - Or note “none”
• Diagnosis code supports indication - ICD-10 shows angle-closure glaucoma
• Post-operative IOP documented - At least initial IOP after procedure
• Anterior chamber status documented - Hyphema or blood, clarity

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RED FLAGS FOR AUDITORS

66761 claims are at audit risk if:

• ❌ Operating microscope NOT documented or used (high risk of downcode to 66762 or denial)
• ❌ Gonioscopy findings missing (no angle assessment documented)
• ❌ No documentation of angle-closure glaucoma (vague indication)
• ❌ No IOP documentation (no pre/post IOP readings)
• ❌ Surgical technique vague (no description of iris manipulation, tissue removal)
• ❌ No documentation of post-operative angle status
• ❌ No confirmation that iridotomy patent post-operatively
• ❌ Documentation appears copy-pasted
• ❌ Diagnosis code unrelated to angle-closure glaucoma
• ❌ Eye not specified (which eye treated?)
• ❌ No optic nerve assessment documented
• ❌ Laser iridotomy performed but coded as 66761 (should be 65855)

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FREQUENTLY ASKED QUESTIONS (FAQs)

Q: What’s the difference between 66761 and 66762?
A: Both are surgical iridotomy for angle-closure glaucoma. 66761 uses operating microscope (3.92 RVU). 66762 is performed without operating microscope (3.28 RVU). If you used an operating microscope, bill 66761. If not, use 66762. Documentation must verify microscope use.

Q: Should I bill 66761 or 65855 (laser iridotomy)?
A: 66761 is surgical iridotomy; 65855 is laser iridotomy. Completely different procedures. 65855 is performed first-line in most acute angle closure. 66761 is typically reserved for failed laser attempts or when surgical approach indicated.

Q: Can I bill 66761 + E/M same day?
A: Yes. Bill E/M with modifier -25 (separate identifiable service) + 66761. E/M must be separately identifiable (e.g., pre-operative evaluation is bundled, but separate evaluation for unrelated reason may be billable).

Q: Can I bill for bilateral iridotomies?
A: Yes. Use modifier -50 (bilateral) or bill each eye separately with -RT and -LT. Most insurers pay both eyes.

Q: What if operating microscope was NOT used?
A: Bill 66762 instead (lower RVU 3.28). Do NOT bill 66761 if microscope not used; risk of denial or audit.

Q: Is the iridotomy still considered a “minor surgery” for the 10-day global?
A: Yes, iridotomy is classified as a minor surgical procedure with 10-day global period, even though it involves intraocular surgery. Major glaucoma surgery (trabeculectomy) has 90-day global period.

Q: What if the angle doesn’t open after iridotomy?
A: Document the failed outcome. You still bill 66761 for the attempted procedure. If repeat procedure needed, use modifier -76 (repeat by same physician) or -77 (repeat by different physician).

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REAL-WORLD BILLING TIPS

Tips to Maximize Compliance & Revenue

1. Document operating microscope use clearly - Critical for 66761 vs. 66762 differentiation
2. Include gonioscopy findings - Angle width assessment (Shaffer grade or description)
3. Document pre- and post-operative IOP - Important for medical necessity and outcome
4. Specify right vs. left eye - Use -RT or -LT modifier
5. Confirm iridotomy patency - Document that opening is patent and aqueous flowing
6. Verify angle opened post-operatively - Gonioscopy confirmation
7. Document iris tissue removal - Iridectomy vs. just iridotomy
8. Keep operative notes specific - Avoid generic copy-paste
9. Document optic nerve status - Cup-to-disc ratio and glaucomatous changes
10. Check angle-closure glaucoma diagnosis - ICD-10 H40.2x codes for angle-closure glaucoma

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BILLING & CODING RESOURCES

Recommended Resources:

• AMA CPT Manual 2025 - Official CPT code definitions
• CMS Fee Schedule Database: https://www.cms.gov/medicare/physician-fee-schedule
• MAC LCDs: https://www.cms.gov/cclc/lcd
• American Academy of Ophthalmology (AAO): https://www.aao.org (coding resources, glaucoma guidelines)
• American Glaucoma Society: Specialty guidance on glaucoma treatment coding
• Your payer’s provider manual - Payer-specific requirements for glaucoma surgery

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SUMMARY TABLE

Element	Details
Official Definition	Iridotomy/iridectomy for glaucoma, with operating microscope
Global Period	010 days (10-day global)
Work RVU (2025)	3.92
Total RVU (2025, Non-Facility)	6.42
Medicare Payment (2025, Non-Facility)	~$208
Medicare Payment (2025, Facility)	~$174
Typical Time	15-30 minutes
Provider Required	ophthalmologist, glaucoma specialist
Common Modifiers	-RT/-LT (laterality), -50 (bilateral), -25 (separate E/M), -24 (unrelated E/M)
Typical Use	Angle-closure glaucoma treatment, narrow angle prophylaxis
Common Mistakes	Omitting microscope documentation; missing gonioscopy findings; not confirming angle opened post-op
Audit Risk	Moderate-High (microscope use and angle-closure documentation critical)
Bundling	Operating microscope included; do NOT bill separately
Telehealth Allowed	No (requires in-person surgical procedure)

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Document Created: February 2026
Compliant with: 2025 Medicare Physician Fee Schedule, CMS National and Local Coverage Determinations
Last Updated: February 2026