CPT® Code 66175

The CPT® Code 66175 refers to the procedure known as transluminal dilation of the aqueous outflow canal, specifically Schlemm's canal, with the retention of a device or stent. This procedure is primarily indicated for the treatment of open-angle glaucoma, a condition characterized by increased intraocular pressure (IOP) that can lead to optic nerve damage and vision loss. The technique aims to enhance the natural drainage of aqueous humor from the eye, thereby reducing IOP. During the procedure, a scleral flap is created to access the canal, which is then deroofed to expose its interior. A flexible hollow microcatheter with a lighted tip is introduced into the canal, allowing for visualization and navigation. A viscoelastic agent, such as high viscosity sodium hyaluronate, is instilled to facilitate the dilation of the canal. Unlike the related procedure coded as 66174, which does not involve the retention of a device, CPT® Code 66175 includes the placement of a stent or suture within the canal to maintain its patency. This retention is crucial as it helps to keep the canal open, thereby ensuring continued drainage of fluid and management of IOP in patients suffering from glaucoma.