CPT® Code 66179

The procedure described by CPT® Code 66179 involves the creation of an aqueous shunt to an extraocular equatorial plate reservoir through an external approach, specifically without 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 channels and aqueous veins. In cases where traditional medical therapies or surgical options, such as trabeculectomy, have proven ineffective in managing elevated intraocular pressure (IOP), this procedure serves as an alternative solution. The aqueous shunt effectively bypasses the trabecular meshwork and Schlemm's canal, thereby alleviating the pressure within the eye. The procedure is particularly indicated for patients experiencing increased IOP due to conditions such as iris swelling, abnormal vessel formation, or iridocorneal endothelial (ICE) syndrome. During the operation, 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 subsequently absorbed by the blood vessels on the surface of the anterior eye. The procedure may also involve the application of Mitomycin C, a cytotoxic drug, to minimize scarring, followed by the instillation of antibiotic and/or steroid drops, and the application of a contact lens bandage before patching the eye. This comprehensive approach aims to effectively manage IOP and improve patient outcomes.