Narrow-angle glaucoma, or closed-angle or angle-closure glaucoma, is a type of glaucoma that manifests suddenly.
The primary reason for the development of narrow-angle glaucoma is the buildup of fluid behind the iris. This can cause a quick increase in intraocular pressure (IOP).
A Medical EmergencyNarrow-angle glaucoma is different from open-angle glaucoma and rarer. It affects 1 in every 1000 individuals.
The frontal part of your eye contains the anterior chamber. While a majority of the population has a normal anterior chamber, it is shallow in some people. Shallow anterior chambers reduce the angle. The iris in such eyes tends to bunch up when the pupil dilates and it closes off the angle. The iris can also close the angle in a dark room.
In a few cases, inflammatory eye diseases can cause the anterior chamber to become sticky. This causes the iris to stick to the lens, which results in intraocular fluid pushing the iris and closing the angle (pupillary block).
Eye diseases related to severe diabetes and tumors can result in the development of narrow-angle glaucoma.
Narrow-angle glaucoma has to be treated as a medical eye emergency. If the intraocular pressure does not reduce quickly, then it can result in permanent vision loss.
Symptoms of Narrow-Angle GlaucomaSymptoms of narrow-angle glaucoma can vary from person to person. While some might not experience any symptoms, others might experience it intermittently. This is dependent on the primary cause of glaucoma.
Some of the common symptoms include
- Pain and inflammation
- Blurred vision
- Pressure over eyes
- Mild pupil dilation unrelated to lights
- Red eyes
- Cloudy cornea
- Extreme light sensitivity
- Halos around lights
- Nausea that can be accompanied by vomiting
Treatment of Narrow-Angle GlaucomaLaser iridotomy is the most preferred treatment choice for narrow-angle glaucoma. An outpatient procedure, iridotomy can be completed in one sitting.
The primary purpose of using laser iridotomy is the equalization of pressure between the anterior and posterior chambers.
The doctor, in this procedure, will first use pilocarpine drops to dilate the pupil and make the iris thinner. After 20 to 30 minutes, the surgeon will use a laser to develop a hole in your iris which will help in restoring the fluid flow to the front.
The doctor will place the hole (usually about one-half of a millimeter) at an appropriate place depending on the severity, but in most cases, the surgeon will place the iridotomy in the superior peripheral iris, usually under the upper eyelid.
Once a hole is made, the intraocular fluid can flow freely from the posterior portion to the anterior portion where the trabecular meshwork helps in draining it. The free flow of fluids helps in decreasing IOP.
A laser iridotomy once performed does not close because of the presence of certain chemicals in the aqueous fluids. Because of this, the chances of future development of pupillary blocks decreases to a large extent. The only exceptions to this are eyes that have a growth of new blood vessels or an eye that has an inflammatory disease.
If you have bleeding issues, your surgeon might use argon laser first and then complete the iridotomy with Nd: YAG laser.
AftercareOnce the procedure is completed, the doctor places apraclonidine in the treated eye and checks the IOP on an hourly basis for a few hours. If there is an increase in IOP, it is treated immediately.
As inflammation is inherent in these types of procedures, your doctor will apply corticosteroids every five minutes for the first 30 minutes after the surgery and then on an hourly basis for six hours.
After this, the drops should be used every six hours a day for one week. Postop follow up is scheduled 1 to 6 weeks post-surgery. If your doctor detects any complication, an appropriate treatment protocol is initiated. Your doctor also performs a visual field test to assess the damage caused to the optic nerve. Of note, you do not wear a patch after the surgery.
The TakeawayNarrow-angle glaucoma is a severe disease and should be dealt with promptly. Once the procedure has been completed, it is important to have annual eye checks to make sure no further complications arise.