What does the treatment involve?
There are various types of glaucoma and the majority of cases are asymptomatic. It is not until the advanced stages of the disease that a loss of vision and peripheral visual field is evident.
An exception to this rule is closed angle glaucoma, in which a sudden increase in intraocular pressure accompanied by blurred vision, red eyes, dilated pupils, severe eye pain and even nausea and vomitting may occur.
This is due to the fact that the aqueous humour exit passageway is compromised as the camerular angle is obstructing the iris. It is an eye emergency and must be treated quickly with a procedure called a Nd-YAG laser peripheral iridotomy.
When is this treatment indicated?
A complete and thorough eye exam can identify in good time those who have an anatomical eye predispostion that could put them at risk of suffering from what is commonly known as an "acute glaucoma attack".
These patients would undergo a preventive Nd:YAG laser peripheral iridotomy, thus avoiding the possibility of them suffering acute decompression of intraocular pressure in the future.
How is it performed?
The treatment involves make a small hole in the peripheral part of the iris using a Nd-YAG laser which does not require incisions.
To do so, around 30 minutes before the procedure, eyedrops are added to contract the pupil, which facilitates the effect of the laser on iridian tissue.
Then, anaesthetic drops are added and a lens is placed on the eye for a better view of the area of the iris to be treated. The procedure does not usually cause any discomfort and normally lasts a few minutes.
Once complete, the lens is removed, anti-inflammatory and anti-hypertensive eye drops are applied, a check is made to confirm that everything is in order, then the patient is discharged.
It is an outpatients treatment and does not require any prior preparation by the patient. We advise that you bring someone with you as you may experience blurred vision due to the drops used to contract the pupil and some passing glare from the light of the microscope used in the procedure.
Daily activities can be resumed the day following the intervention. After a few days, during which you should apply anti-inflammatory and anti-hypertensive eyedrops, the patient undergoes a check-up to examine their progress and the final result.
Results
In the case of an acute glaucoma attack, a reduction in intraocular pressure and in the symptoms is usually observed soon after the treatment.
The patients who undergo this procedure for preventive reasons usually experience blurred vision and photophobia that usually disappears after a few days. Occasionally, the patient seee reflective light called "dysphotopsia" which may persist for a long time.
Possible risks
An Nd: YAG laser peripheral iridotomy is a non-invasive procedure that is very safe. Some patients will find that their intraocular pressure increases temporarily, which will happen for a few hours after the treatment is first applied.
Furthermore, mild intraocular inflammation may be observed. To counteract these postoperative complications, anti-inflammatory and anti-hypertensive eyedrops must be applied for 5 to 7 days.
It is rare that mild intraocular haemorrhages occur, but if they do they are generally reabsorbed in a few days without any sequelae of any type.