CPT® Code 66180

The procedure described by CPT® Code 66180 involves the creation of an aqueous shunt to an extraocular equatorial plate reservoir through an external approach, which includes the use of a graft. This surgical intervention is designed to facilitate the normal outflow of vitreous fluid, which typically begins at the aqueous humor and passes through the trabecular meshwork, entering Schlemm's canal, and ultimately draining into the collector channel and aqueous veins. In cases where traditional medical therapies or surgical options, such as trabeculectomy, have proven ineffective, this procedure serves as an alternative to reduce intraocular pressure (IOP). The aqueous shunt effectively bypasses the trabecular meshwork and Schlemm's canal, addressing conditions that lead to increased IOP, such as iris swelling, abnormal vessel formation, or iridocorneal endothelial (ICE) syndrome. During the procedure, the patient is positioned supine and placed under general anesthesia. A small silicone tube is implanted into the anterior chamber of the eye, allowing for the drainage of vitreous fluid through the tube into a small plate that is sutured onto the anterior eye, typically located between the sclera and conjunctiva in the upper eyelid area. This plate collects the vitreous fluid, which is then absorbed by the blood vessels on the surface of the anterior eye. In the context of CPT® Code 66180, a scleral or corneal patch graft from donor tissue may be utilized to cover the plate, ensuring its stability and minimizing the risk of conjunctival ulceration. Additionally, at the conclusion of the procedure, a cytotoxic drug, Mitomycin C, may be applied briefly to mitigate scarring before being flushed away. Post-operative care may include the application of a contact lens bandage and the instillation of antibiotic and/or steroid eye drops, followed by patching of the eye.