Within the eye, a clear fluid called aqueous humor circulates to provide nutrition and maintain its shape. Produced behind the iris, this fluid flows through the pupil to drain at the front of the eye. If this drainage pathway becomes obstructed, pressure can build rapidly, a condition known as angle-closure glaucoma that can damage the optic nerve. To resolve the blockage, ophthalmologists create a new path for the fluid using procedures like an iridotomy or an iridectomy.
Understanding Laser Iridotomy
A laser peripheral iridotomy is the most common procedure for treating and preventing angle-closure glaucoma. Performed in a doctor’s office, this minimally invasive technique uses a laser to create a tiny opening in the outer edge of the iris. This new channel allows aqueous humor to flow directly from behind the iris to the front, bypassing the pupil.
This pressure equalization causes the iris to move away from the eye’s internal drainage system, widening the angle and restoring normal fluid outflow. The laser used is often a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, which creates the opening without a physical incision. The procedure is recommended as a preventative measure for individuals with anatomically narrow angles, putting them at high risk for an acute angle-closure attack. For patients experiencing an attack, an iridotomy is the definitive treatment to quickly lower eye pressure.
The process is quick, completed in minutes using only anesthetic eye drops. Patients may see a brief flash of light and feel a slight sensation but are generally comfortable. Its minimally invasive nature and low risk of complications make it the standard treatment for conditions related to a narrow drainage angle.
Understanding Surgical Iridectomy
A surgical iridectomy is an incisional procedure where a surgeon removes a small, full-thickness piece of the iris. Instead of creating a hole with a laser, an iridectomy excises a wedge-shaped section of tissue. This creates a permanent opening for aqueous humor to flow between the eye’s chambers. The procedure is performed in an operating room and requires a local or, in some cases, general anesthetic.
Historically, surgical iridectomy was the primary method for treating angle-closure glaucoma, but its use for this purpose is now rare. The laser alternative is safer and less invasive. Opening the eye for a surgical iridectomy when pressure is high increases the risk of complications, which the non-incisional laser procedure avoids.
A surgical iridectomy is now reserved for specific, complex situations. It may be performed with other eye surgeries, like a trabeculectomy for glaucoma or a complicated cataract extraction. It is also used for removing an iris melanoma or repairing the iris after trauma, as these scenarios require the direct removal of tissue that a laser cannot perform.
Comparing the Procedures and Recovery
The fundamental difference between the two procedures is their method and level of invasiveness. An iridotomy is performed in an office setting with a laser, requiring no surgical cuts. In contrast, an iridectomy is an intraocular surgery done in an operating room, involving an incision and the use of surgical instruments to excise tissue. This distinction directly impacts the patient’s recovery process.
Recovery from a laser iridotomy is fast. Patients go home shortly after the procedure and can resume most normal activities within a day. Side effects are mild and temporary, including blurred vision, minor discomfort, and a short-term spike in eye pressure that is monitored. A less common long-term side effect is new glare or halos caused by light passing through the opening in the iris.
Recovery from a surgical iridectomy is longer and more involved. Patients must use antibiotic and steroid eye drops for several weeks to prevent infection and control inflammation. An eye patch is often worn immediately after surgery, and activities like bending and heavy lifting are restricted. Sutures may be used to close the incision and might require later removal.
The associated risks also differ. For a laser iridotomy, risks include inflammation, bleeding at the laser site, and the opening closing over time, which may require a repeat procedure. A surgical iridectomy carries the risks of any eye surgery, such as infection, significant bleeding inside the eye, and complications from anesthesia.
How a Doctor Decides Which Procedure is Necessary
An ophthalmologist’s choice between a laser iridotomy and a surgical iridectomy is guided by the patient’s specific diagnosis. For treating and preventing primary angle-closure glaucoma, laser iridotomy is the standard of care. Its high success rate, minimally invasive nature, and safety profile make it the preferred method.
A doctor will opt for a surgical iridectomy only when a laser procedure is not feasible or sufficient. This may be the case if the cornea is too cloudy for the laser to pass through and focus on the iris. A surgical approach is also used when a larger opening is needed or if a previous iridotomy has closed.