Summary & Overview
CPT 66635: Iris Tissue Removal to Enlarge Pupil
CPT code 66635 represents an ophthalmic surgical procedure to remove part of the iris to enlarge the pupil and improve vision. This anterior segment surgery can be clinically indicated for patients with restrictive pupil function that impairs visual acuity or access to other intraocular procedures. Nationally, accurate coding for this procedure affects clinical documentation, surgical quality tracking, and payer adjudication for ophthalmology services.
Key payers typically included in analyses are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication provides readers with an overview of the clinical context for CPT code 66635, expected sites of service, and common billing considerations. Benchmarks and payer coverage patterns are summarized where available; when specific data elements are missing in the input, the text notes that data are not available.
Readers will learn the clinical intent of the code, the typical service setting for the procedure, and which major national payers are relevant to coverage discussions. The content is intended for billing managers, ophthalmology clinicians, and policy analysts seeking a concise reference on coding and the procedural role of CPT code 66635 within ambulatory and hospital-based ophthalmic care.
Billing Code Overview
CPT code 66635 describes a surgical procedure in which the provider removes part of the iris (iridectomy or iridotomy-type tissue removal) to enlarge an existing pupil with the goal of improving the patient’s vision. This procedure is an ocular surgical service focused on the anterior segment of the eye.
Service type: Ophthalmic surgery — iris tissue removal to enlarge pupil
Typical site of service: Hospital outpatient department or ambulatory surgical center (ophthalmic surgery setting)
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A typical patient is a 65-year-old with medically significant visual impairment from a small, fixed pupil due to chronic iridocorneal adhesions or traumatic iris sphincter damage, presenting with glare, photophobia, and decreased visual acuity despite optimal medical therapy and corrective lenses. The ophthalmologist evaluates visual acuity, slit-lamp exam, intraocular pressure, and documents a scarred or constricted pupil that cannot be adequately dilated. Preoperative workup includes informed consent, ocular measurements, potential anticoagulation review, and discussion of alternatives (e.g., peripheral iridotomy, prosthetic iris device). On the day of service in an ambulatory surgery center or hospital outpatient department, under monitored anesthesia care or local anesthesia with sedation, the surgeon performs a surgical iris sphincterotomy/iridectomy to remove part of the iris margin to enlarge the existing pupil to improve vision. Postoperative workflow includes same-day recovery, topical antibiotics and steroids, follow-up visits to assess inflammation, intraocular pressure, and functional visual improvement, and documentation of any complications. Typical sites of service are an outpatient ophthalmic surgery center, hospital outpatient department, or rarely an office procedure suite with appropriate sterile field and anesthesia support.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 | Increased procedural services | Use when the procedure required substantially greater work than usual due to extensive synechiolysis or complex iris pathology. |