Cataract is clouding of the lens inside the eye. The human eye has a lens inside it, located behind the iris. The lens is the “zoom” of the eye and it helps focusing the light rays onto the retina. When the lens becomes cloudy enough to affect the patient’s quality of life, we do cataract surgery and we remove it with a procedure called phacoemulsification.
The lens of the eye is held in a thin clear membrane called the capsular bag. During cataract surgery, the natural opacified lens is removed from the capsular bag after opening a “window” in the front part of it and replaced with a clear plastic lens called intra-ocular lens.
Over time, the remaining capsule (your own capsular bag) behind the intra-ocular lens can thicken resulting in blurred vision – like looking through a foggy window. This condition is called posterior capsular opacification (PCO). Sometimes it gives glare when driving at night from the coming lights.
When this happens, some people incorrectly think that their cataract has come back. Cataract never comes back, but it is the posterior capsular opacification (PCO) that some people experience after cataract surgery.
It is estimated that about 20% of people develop posterior capsular opacities after cataract surgery within 5 years from the surgery (5 to 50% depending on the type of the intra-ocular lens, the age when you had surgery – the younger the more common and many other factors).
Figure 1. Before cataract surgery – the capsular bag
Figure 2. After cataract surgery, posterior capsular opacification – PCO
YAG laser capsulotomy is a type of laser treatment that is used to make a hole in this capsule to help you seeing better.
The treatment is routinely done as an out-patient procedure and involves no surgical cuts. It uses the cutting characteristics of the YAG laser to cut a window in the PCO.
Figure 3. YAG laser capsulotomy – opening a window in the posterior opacified capsule (PCO) using laser beam
BENEFITS AND POSSIBLE RISKS
The benefit of having YAG laser capsulotomy is to make your vision better.
YAG laser capsulotomy is a very safe procedure; however, like anything in medicine, there are some risks which are not common. The risks, which are rare, include:
- Raised intra-ocular pressure (the pressure inside the eye) – Usually short term and can be treated with eye drops
- Inflammation inside the eye – Usually short term and can be treated with eye drops
- Swelling of the retina, that may need further treatment
- In very rare cases retinal detachment that requires surgery which has high success rate
- Mild damage to the intra-ocular lens – these are tiny scratches that occasionally are unavoidable but they rarely affect vision
You are likely to experience increased floaters within the eye straight after the procedure, but these will become less noticeable after a few weeks. This is because we are not removing the capsule of the lens from your eye as we did during cataract surgery with the front part of the capsular bag, but we are cutting a window in the back part of the lens capsule and we push the cut piece inside the vitreous (the gel filling the eye ball). So, the floater or the veil some patients see after YAG laser capsulotomy is their own membrane that we pushed inside the vitreous.
THE LASER PROCEDURE
On arrival to the clinic on the day of the laser treatment, you will have eye drops to dilate your pupils and anaesthetic eye drops just before treatment.
You will be asked to sit in a chair and rest your chin on the chin rest of the laser machine which looks the same as the usual machine your eye doctor or optician use to examine your eyes.
A contact lens will be placed on the surface of your numbed eye. The contact lens focuses the laser beam, helps keeping the eye still and keeps the eyelids apart so you don’t have to think about keeping your eyes open. You can continue blinking as normal. The procedure is painless, but it could be slightly uncomfortable because of the bright light of the laser machine.
After the laser procedure, your vision will be very blurred because we shined a strong light into your eye during the procedure and you could not close the “lasered” eye because of the lens we inserted on your eye. This will get better within a few minutes.
You will be given eye drops to take home to prevent inflammation.
You will notice the improvement of vision within 24 hours.
POST-LASER INSTRUCTIONS
There are no restrictions following laser capsulotomy. Carry on with all your normal daily activities.
WILL I BE ABLE TO DRIVE HOME?
No, you will not be able to drive home following treatment due to the eye drops used that will temporarily dilate your pupils and blur your vision.