Narrow Angle Glaucoma

In  Angle Closure or Narrow Angle Glaucoma,  the iris physically obstructs the internal drain of the eye. In contrast to the normal open angle the iris floats forward covering over the drainage area obstructing iit. Fluid pressure builds behind the iris, causing it to billow forward (see below) and eventually, often suddenly, flop up against the drainage (“trabecular”) meshwork. When this happens, the pressure rises quickly. Pain, haloes around lights, even nausea often result. This type of glaucoma usually develops suddenly. It is called an attack of acute angle closure glaucoma. That is why it is important that in doing our routine complete eye examinations, we screen for narrowing of the angle before it becomes symptomatic. When it is suspected, a simple test called gonioscopy confirms the diagnosis. Many cases are thus prevented when the narrow angle is detected before there actually are symptoms. Laser treatment at this time prevents most cases of a glaucoma attack and carries an excellent prognosis. It is common for patients to become anxious at this unexpected finding and a surprise recommendation for prompt treatment, although after the treatment is done they generally are surprised how easy the treatment was.

Acute Narrow Angle Glaucoma

When the symptoms have begun (angle closure attack), the treatment is urgent. Emergency treatment is required for this acute and often painful condition. Laser Therapy is nearly always effective in resolving the attack. However, if the attack has been going on for any length of time, irreversible nerve damage may occur resulting in permanent vision loss. Medical Therapy may still be necessary after successful laser treatment. That is because some patients will still have “open angle” glaucoma after the attack is relieved. Some others will have developed permanent scar tissue from the angle closure (called chronic angle closure) and they, too, may need medication (or in some cases surgery) to manage that problem. Surgery is relatively infrequent but may be very helpful.

Laser Treatment for Narrow Angle Glaucoma (Iridotomy)

Fortunately, Angle Closure (narrow angle glaucoma) may be quickly and simply relieved, or even prevented, by making a small opening (laser iridotomy) in the iris to relieve the blockage of fluid behind the iris. This is usually so small as to be an invisible opening, and for nearly everyone it is hidden as well by the upper eyelid. This is best done before an attack when the risk is diagnosed (often during a routine eye examination). The procedure is performed painlessly with use of a laser. You do not need to go to the hospital for treatment. We treat our patients on our premises, in the Marin Ophthalmic Surgery Center.