What are narrow angles?

The angle refers to the “drain of the eye”. It is the space in the front of the eye between the cornea (outer clear part of the eye) and the iris (colored part of the eye). 


It is responsible for making sure the natural fluid within the eye, called the aqueous humor, drains effectively and efficiently. This in turn maintains the eye pressure (IOP). 


“Narrow angles” is a condition where this drain is anatomically shallow. This puts you at risk for a sudden “glaucoma attack”. 

In a glaucoma attack, fluid builds up in the eye causing a sudden increase in IOP. This dramatic rise in IOP leads to optic nerve damage, which can cause irreversible vision loss. The risk of such an attack is about 1% per year. 


For most patients, treating narrow angles is a preventive measure to open up the angle/drain and reduce the risk of a sudden attack – this is called laser peripheral iridotomy (LPI).

What is an LPI?

LPI is a quick, effective, in-office procedure. It reduces the risk for  developing or worsening glaucoma. 

A microscopic hole is created in the iris to open the angle and reduce the risk of glaucoma. You cannot see it with the naked eye. It may also lower the eye pressure in certain situations. 

How is an LPI done?

The eye is pretreated with a drop that makes the pupil small. This takes about 20 minutes to work. You may experience a small headache, this is normal. 

The laser itself takes less than five minutes. There is minimal pain. Most people feel slight pressure, if they feel anything at all.

IOP is checked 30 min after the laser. Please allow a minimum of 60 minutes for the visit. 

Risks and side effects: 

In general, risks of the laser are low. There is a small chance of prolonged sensitivity to light and/or glare. This is much less common with new generation lasers like the one in our office. 

About 15% of the time, the angle may not open enough to reduce the risk of glaucoma. Or the hole that is made may close/become smaller over time. If this happens, alternate laser procedures, medications, and/or cataract surgery may be indicated. 

Your vision may be a little blurry on the day of the procedure. Other side effects include redness, sensitivity to light, and foreign body sensation. These typically last 1-2 days after the laser. 


There are NO restrictions. You may exercise, shower, and return to work as soon as you feel comfortable. You will use a steroid eye dropper 1 week after the procedure.

What can I do to reduce the risk of a "glaucoma attack"?

Dilation, like during a routine eye exam, may trigger a glaucoma attack. Make sure to tell all eye care providers about your diagnosis. Avoid medications like decongestants and certain anti-depressants. If your medication, especially a new one, has a warning about  glaucoma, be sure to tell your ophthalmologist about it.   

Will I need eye drops?

In some cases, the pressure increases gradually leading to glaucoma. 

If you have glaucoma, you may still need to use eye drops. LPI is NOT a substitute for eye drops.