Laser Iridotomy


Laser iridotomy is a treatment for narrow (or closed)-angle glaucoma, one of the many types of glaucoma (read more), although it is much less common that Open Angle Glaucoma. Laser iridotomy is typically recommended, although cataract surgery may be an appropriate and sometimes better treatment because the cataract can actually cause the narrow angle by pushing the iris forward towards the cornea.:
  1. After the pressure in the eye has been reduced with medication or when medications fail.
  2. To prevent closed-angle glaucoma attacks in people who have narrow drainage angles, and in those who have had closed-angle glaucoma in their other eye.


In laser iridotomy, a small hole is placed in the iris in order to drain any excess fluid that is causing abnormal pressure in your eye. Usually, this hole is placed in the upper portion of the iris where it cannot be seen under the upper eyelid.


To better understand closed-angle glaucoma and laser iridotomy, it is helpful to first understand how eye pressure works:

The eye is constantly making new fluid (called aqueous humor) to keep the front of the eye filled. At the same time, a matching supply of fluid is constantly leaving the eye. The balance between the volume of fluid made and how much leaves determines the pressure within the eye.

In a normal eye, fluid drains by passing between the iris and crystalline lens before leaving through the drain called the trabecular meshwork. In narrow-angle glaucoma, this flow of fluid is blocked before it reaches the drain.

When the amount of aqueous humor leaving is not enough, the pressure within the eye increases, much like a balloon filled with too much water – fluid is coming in, but not enough is going out. This increase in pressure is what usually leads to glaucoma. Glaucoma occasionally occurs without high pressure (read more about glaucoma).


A laser uses light to deliver a type of concentrated energy capable of creating a safety valve hole in your iris. The laser needs to be precisely positioned for this procedure, and in order to do this, Dr. Seibel will ask you to sit in front of an instrument called a slit-lamp. This is the same instrument that is used during an eye exam. A slit-lamp is actually a type of microscope, so the laser energy will be focused with extreme accuracy.


Laser iridotomy uses the highly focused beam of a laser to create a hole on the outer edge of your iris. This opening allows fluid to properly leave the eye and lower the internal pressure.

The following is what you may expect:

  1. Dr. Seibel will place some different types of drops on your eye. Some of these will make your pupil smaller. This stretches and thins your iris, similar to stretching out the top surface of a drum, making it easier for the laser to penetrate your iris.
  2. The only kind of anesthesia required to perform a laser iridotomy is a numbing eye drop, which makes the laser surgery virtually painless.
  3. Dr. Seibel will next place a special contact lens (coated with a heavy, protective jelly) on your eye to facilitate the focus of the laser upon the iris. This lens also keeps your eyelids separated, to control blinking during the treatment, and reduces small eye movements. The jelly may remain on your eye for a while afterwards, causing your vision to be temporarily blurred.
  4. During the laser treatment, you will see a bright light, like a photographer’s flash from a close distance. You may also feel a painless pinch-like sensation, and then the procedure is over.
  5. After treatment, Dr. Seibel may ask you to stay for a few hours to monitor your eye pressure.
  6. When it is safe, you will be released. You will need to have someone there to drive you home.
  7. You may be asked to use eye drops afterwards to maintain eye pressure and reduce inflammation during the healing process. Dr. Seibel will explain their use and when you need to be examined again.


In general, there are no restrictions in activity following the laser treatment. You may return to your normal daily routine, although driving might not be advised right away. You can expect some redness of the eye, sensitivity to light, and a scratchy sensation. All of these might last for a period of days.

Your may be required to continue using eye drops for a few days following your laser treatment. These drops make your pupil smaller and can cause a temporary blurring of your vision (especially at night) and may also give you a slight headache.


The size of the hole in your iris is only that of a pinhead. Unless you really search for it, neither you nor your friends will even notice it.

The quality of your vision will not be improved by the iridotomy. The purpose of the procedure is to preserve your vision, not to make it better. Laser iridotomy is primarily used to prevent further episodes of sudden (acute) closed-angle glaucoma. And, it can usually prevent slow-forming closed-angle glaucoma in people who are at risk. Also, depending on a lot of other factors, your glaucoma may not be cured after iridotomy. You will still need to be closely monitored for high pressure in the eyes even after your procedure.

Over time, closed-angle glaucoma is known to affect both eyes in about 50% of cases. When one eye has been successfully treated for acute closed-angle glaucoma, iridotomy is usually performed on the other eye as a preventative measure.

Occasionally, even after laser iridotomy, the new drainage opening can become blocked again. If this occurs, iridotomy may be repeated and is often successful.


A laser iridotomy is an extraordinarily safe procedure. Complications, fortunately, are practically unknown.

Potential complications might include: bleeding in the eye, inflammation in the eye, and transient pressure elevations. As such, Dr. Seibel will prescribe eye drop medications (following the procedure) to help prevent these potential complications.

The chance of losing vision following a laser procedure is extremely rare. The main risk is that your iris might be difficult to penetrate and may require more than one treatment session. The other risk is that the hole in your iris will close; this happens in less than 30% of cases. Once the hole stays open for 6 weeks, it is highly unlikely that it will close in the future.

In addition, if there was any damage to the trabecular meshwork prior to the iridotomy or if you also have one of the other types of glaucoma, you may still require medications or other treatments to keep your eye pressure sufficiently low.