YAG laser Capsulotomy ?

If your vision has improved following cataract surgery but become foggy and misty again over time, this does not mean that your cataracts have returned. During cataract surgery your cataract is removed and a thin membrane called the posterior capsule is left behind the new implanted lens. It is more than likely that the membrane immediately behind the implanted lens has become thicker and slightly opaque, making your vision cloudy. This can occur as early as a few months after the cataract surgery, but can also take many years to occur. This thickening of the membrane is called posterior capsular opacification (PCO) and can occur fairly frequently.

In eyes, where the PCO is causing the patient symptoms, we can easily treat this by a laser. This laser is called a YAG laser. It is named after Nd:YAG (neodymium-doped yttrium aluminium garnet; Nd:Y3Al5O12), the crystal that is used as a medium for this laser. This type of laser works by producing a plasma, which results in ablation of the posterior capsule with high precision and minimal thermal and mechanical damage to the surrounding tissues. The laser therefore essentially creates a hole in the central part of the PCO, which then allows the light to pass through the eye, resulting in a clearer image. This laser is also used in the eye for peripheral iridotomy in patients.

The treatment is carried out as an outpatient. The procedure itself takes approximately 15 minutes, but you will be in the hospital for longer. Your vision is checked and then pre-treatment drops will be needed to make the pupil larger (dilate the pupil). Following this, an anaesthetic drop will also be applied to your eye to allow placement of a large contact lens on the eye. The contact lens helps focus the eye laser as well as preventing blinking. Once the procedure is underway you may see some bright flashes or hear a tapping sound. After the procedure, you are allowed to return home and sometimes may be given some additional drops to prevent inflammation or a rise in pressure in the eye. The vision may remain blurred for 3-4 hours (a result of the larger pupil) but should return to normal by the end of the day. We therefore ask that you do not drive home after the procedure. You can resume normal activities the following day.

If you have had cataract surgery and your vision is misty again, please contact your doctor or optometrist who may send you to the hospital for laser treatment of your PCO.

What are the risks and complications of a laser capsulotomy?

Floaters are common after the procedure and are usually due to the fragments of the PCO. This usually becomes less noticeable with time. There is an increased risk of retinal detachment after the procedure especially if you are short sighted. If you see increased new floaters, flashing light or shadows in the vision you must contact an optician or an ophthalmologist urgently to check your retina. Swelling of the retina (macular oedema) may sometimes occur but usually improves over time. Very rarely the lens can be dislocated and require repositionaiing. There is a small risk of raised pressure in the eye and we occasionally give your drops if you are at risk of this.

As with any procedure there is a always a small risk of vision getting worse and sometimes a second treatment may be needed.

Sumit Dhingra

"Thank you for your exquisite care when my doctor referred me for your opinion. Your careful and unhurried assessment and thoughtful advice were exemplary. You relieved my anxiety, explaining carefully the significance of the episode, and gave confidence on the action to take should similar problems recur."