Yag laser peripheral iridotomy is a treatment for primary angle closure, narrow angle and narrow angle glaucoma. An Nd:YAG laser to create a small hole in the peripheral iris. This improves the circulation of fluid inside the eye and widens the anterior chamber angle. Fluid which is produced behind the iris bypasses the iris and has an easier access to the eye's internal drainage system between the iris and the cornea. This might lower the pressure in the eye, but that is not the primary goal of laser peripheral iridotomy. The primary goal of the procedure is to reduce the risk of acute angle-closure glaucoma. This is not aimed at improving vision. 

Please note that: Vision once lost from glaucoma can not be regained. All treatment/operation for glaucoma is aimed at slowing down the rate of progression of glaucoma so that the risk of complete blindness in one's lifetime may be reduced.

Yag laser peripheral iridotomy eliminates pupillary block by allowing the aqueous to pass directly from the posterior chamber into the anterior chamber, bypassing the pupil.

The fellow eye in a patient with acute angle-closure glaucoma or chronic angle-closure glaucoma has a 50% chance of developing acute angle-closure glaucoma.Therefore, if a narrow or occludable angle is noted on examination, Yag laser iridotomy is offered to the fellow eye of the affected eye as a prophylactic treatment to reduce the risk of acute angle closure glaucoma.

Certain patients, especially hyperopic (far sighted) patients, are at increased risk of having narrow angles. Therefore, gonioscopy (viewing drainage angle using a special contact lens) should be performed. If narrow/occludable angle is noted on the examination, Yag laser iridotomy is recommended.

This procedure is performed in the outpatient clinic. You will be explained about the procedure and an informed consent will be taken from you. You will have your vision and eye pressure checked followed by some eye drops (one of the drops will constrict your pupil and might give you transient browache/headache for few hours). During the laser you will be seated upright infront of the laser machine which looks similar to the machine in the photograph at the top of this page. You will have some anaesthetic drops on your eye and a special contact lens will be put on your eye for the laser treatment. The laser takes about 5-10 minutes.

You will have eye drops after the laser treatment and your eye pressure will be checked about an hour later. You will be prescribed some eye drops to use to that eye for 4 weeks and will be reviewed back in 1-2 weeks in the clinic.

If you happen to experience reduced vision, pain and red eye please do contact your local eye emergency without delay.

Furher related information  http://emedicine.medscape.com/article/1844179-overview

Yag Laser Peripheral Iridotomy video:

http://www.youtube.com/watch?v=l_HNTuVv7cI

Various Glaucoma treatment including laser iridotomy video:

http://www.youtube.com/watch?v=X9NgArAMAQ8