CPT® Code 0621T

1. Indications

The trabeculostomy ab interno by laser is indicated for patients diagnosed with glaucoma, particularly when there is a need to reduce intraocular pressure (IOP) to prevent the progression of the disease towards blindness. This procedure is suitable for individuals who may benefit from a minimally invasive surgical option that aims to improve aqueous outflow and manage their condition effectively.

• Glaucoma Diagnosis Patients diagnosed with glaucoma requiring intervention to lower IOP.
• Progressive IOP Elevation Individuals experiencing elevated IOP that poses a risk of optic nerve damage.
• Minimally Invasive Surgery Preference Patients seeking a micro-invasive surgical option with a favorable safety profile.

2. Procedure

The procedure begins with the creation of a clear corneal incision, which measures a minimum of 0.8 mm. This incision allows access to the anterior chamber (AC) of the eye. To prevent the collapse of the AC during the procedure, a viscoelastic substance is introduced. Following this, a goniolens is placed on the cornea, or alternatively, an ophthalmic endoscope may be utilized to visualize the trabecular meshwork. The next step involves the advancement of a 500 μm diameter probe through the AC, ensuring that the bevel of the probe is oriented upwards as it makes contact with the trabecular meshwork. Once in position, the physician employs a foot pedal system to activate the laser, which is used to create approximately ten microchannels in the trabecular meshwork. These channels are spaced about 500 μm apart and cover an arc of 90 degrees. As the laser is applied, it photoablates the tissue, converting it into gas, which may result in the appearance of blood and microbubbles as reflux from Schlemm’s canal. This process is theorized to enhance the outflow tract further by inducing a pneumatic effect that dilates Schlemm’s canal, thereby improving the drainage of aqueous humor.

• Step 1: Incision Creation A clear corneal incision of at least 0.8 mm is made to access the anterior chamber.
• Step 2: Viscoelastic Introduction A viscoelastic substance is injected into the anterior chamber to maintain its structure during the procedure.
• Step 3: Visualization Setup A goniolens is placed on the cornea, or an ophthalmic endoscope is used for visualization of the trabecular meshwork.
• Step 4: Probe Advancement A 500 μm diameter probe is advanced through the anterior chamber into contact with the trabecular meshwork.
• Step 5: Laser Application The physician uses a foot pedal system to apply the laser, creating approximately ten microchannels over 90 degrees.
• Step 6: Microbubble Formation The application of the laser may result in blood and microbubbles appearing as reflux from Schlemm’s canal.
• Step 7: Pneumatic Effect The procedure is theorized to produce a pneumatic effect that dilates Schlemm’s canal, enhancing aqueous outflow.

3. Post-Procedure

After the completion of the trabeculostomy ab interno by laser, patients may experience some transient effects such as mild discomfort or visual disturbances, which typically resolve quickly. It is essential for patients to follow post-operative care instructions provided by their healthcare provider, which may include the use of prescribed eye drops to manage inflammation and prevent infection. Regular follow-up appointments are necessary to monitor intraocular pressure and assess the effectiveness of the procedure. Patients should be advised to report any unusual symptoms, such as significant pain or changes in vision, to their physician promptly. Overall, the recovery period is generally swift, with many patients resuming normal activities shortly after the procedure.