Posterior Capsule Opacification and YAG Laser Capsulotomy

Cataract surgery is a wonderfully successful procedure for improving vision. During surgery, your cloudy cataract is replaced with an artificial lens implant that permanently resets your vision. However, months or years after the operation, many patients will notice that their vision becomes slightly blurry again.

The most common reason for this is called ‘posterior capsule opacity’ (PCO). This is a minor problem that is easily treated with a brief and painless laser procedure. In this article I will explain posterior capsule opacity and its management.

Above: the surgical steps of cataract surgery

What is Posterior Capsule Opacity?

Cataract is a clouding of the natural lens inside the eye. During cataract surgery, your ophthalmologist removesthe cloudy cataract but leaves behind the delicate lens capsule. An artificial intraocular lens (IOL) is then injected into this lens capsule. Over the following weeks the lens capsule will shrink wrap around the IOL to hold it securely in place.

The lens capsule is coated with living cells that once formed part of your cataract. These remaining cells can multiply and migrate across the lens capsule. As they grow, the lens capsule becomes cloudy, wrinkled and opaque. Thisis known as Posterior Capsule Opacification (PCO).Even though your artificial IOL remains perfectly transparent, the clouding of the lens capsule (called PCO), can make your vision blurry.

Most patients will develop posterior capsule opacity if they live long enough. If you have had cataract surgery in both eyes, PCO can affect both eyes, but each eye may be affected at different times.

Above: Photograph of Posterior Capsule Opacity (PCO) growing behind an intraocular lens. The pale tissue is the PCO, which clouds the vision. The opaque cells are called Wedl cells.

What are the symptoms of Posterior Capsule Opacity?

The symptoms of PCO are very similar to the symptoms of cataract.

  • Blurred vision. This usually develops gradually, over months or years.
  • Seeing glareand streaks around lights at night.
  • Difficulty reading, including road signs when you’re driving.

Risk factors for developing Posterior Capsule Opacity

You may wonder why some patients develop PCO months after their cataract surgery, while other patients don’t develop it for many years. There are several reasons for this, including the intraocular lens material, surgical technique, and age of the patient. Below is a list of the key risk factors fordeveloping PCO.

Risk factor 1: Intraocular lens material and design

The most important factor affecting your likelihood of developing PCO is the material that your artificial intraocular lens is made of. Although all modern intraocular lenses are made from acrylic plastic, this exists in two forms: acrylics that attract water (hydrophilic) and acrylic that repel water (hydrophobic).

Intraocular lenses made from hydrophilic acrylic are much more prone to attracting PCO than lenses made from hydrophobic acrylic. It has been calculated that hydrophilic lenses may be 30-70 times more likely to develop PCO than hydrophobic lenses.  However, many surgeons will still choose to implant hydrophilic intraocular lenses due to their thinner size and favourable optical properties.

The edge profile of your intraocular lens also significantly influences your likelihood of developing PCO. Lenses that have square, sharp edges have a much lower risk of PCO than lenses with smooth round edges. Research indicates that the square edge acts as a physical barrier that impedes the migration of lens cells across the lens capsule. Intraocular lenses with square edges therefore help to prevent PCO from reaching the centre of the lens capsule, where it would cloud a patient’s vision.

Hydrophilic lenses inherently have less-square edges than hydrophobic lenses, as they are made from a dehydrated material that is cut and then rehydrated. As the lens rehydrates it swells, causing the lens edge to becomes slightly rounded. In contrast, hydrophobic lenses are cut to shape and left permanently dehydrated. This leaves the edge profile square and sharp.

Risk factor 2: Your age

Younger patients develop posterior capsule opacity much faster than older patients. Young patients heal more vigorously following any surgical procedure – their lens capsule also tends to opacify much faster. Children undergoing cataract surgery will invariably develop posterior capsule opacity, usually within 12 months of the surgery (or less). In contrast, many 80 year old patients may not develop significant PCO within their lifetime. When performing cataract surgery for patients less than 55 years of age I tend to favour hydrophobic intraocular lenses, to help to delay their onset of PCO.

Risk factor 3: Meticulous Surgical Technique

Although PCO is not a serious problem, I always do everything I can to delay its onset for my patients. There are two main surgical strategies to reduce the likelihood of PCO when performing cataract surgery.

Firstly, I always pay meticulous attention to polishing the patient’s lens capsule to remove as many residual lens cells as possible. I use a soft silicone capsular polisher for this purpose, as the lens capsule is incredibly delicate (just 3 microns in thickness!). Removing all lens cells from the capsule is facilitated by performing exactly correctly a step of the operation called “hydrodissection”. During this step, I inject sterile water between the lens capsule and the cataract, to from a cleavage plane that precisely separates the cataract from the capsule. Attention to detail with this step is one of the most under-appreciated aspects of modern day cataract surgery (in my humble opinion!).

The other surgical step that slows the onset of PCO is the capsulorrhexis. This is the circular opening that is made at the front of the lens capsule in order to access the cataract. The perfect capsulorrhexis is a circle 5.5mm in diameter centred on the pupil. This perfectly-sized capsulorrhexis enables the capsule to tightly shrink-wrap around the intraocular lens in a manner that impedes the growth of residual lens cells.

The Treatment of PCO: YAG laser capsulotomy

Similar to a cataract, PCO causes gradual blurriness of vision. Fortunately, the treatment of PCO is easy, safe, and painless. Furthermore, the treatment lasts for life and therefore only needs to be performed once.

PCO is removed using a laser procedure performed in clinic. The procedure is called “YAG laser capsulotomy”. The ‘YAG’ refers to the type of laser used to generate the laser energy – a neodymium yttrium aluminium garnet (Nd:YAG) laser.

What is YAG laser capsulotomy?

YAG laser capsulotomy is a procedure that uses short pulses of laser energy to cut a window in the cloudly lens capsule, so that light can pass through to the retina unobscured. The procedure is brief (less than three minutes), painless, non-invasive, and is performed in the clinic with you sitting in a chair.

How does the YAG laser work?

The YAG laser delivers pulses of infrared light to remove the cloudy lens capsule. Each pulse is just three nanoseconds in duration and is highly focused, such that the total energy delivered is tiny. The laser precisely removes the lens capsulewithout causing any damage to surrounding structures. YAG laser capsulotomy is performed on hundreds of Australians every day and is extremely safe. At Sight Specialists, we have invested in the Ellex Tango Reflex laser, which is arguably the most sophisticated YAG laser in the world. It is also an Australian product!

Above: The Ellex Reflex Tango Laser that I use at Sight Specialists

How is YAG laser capsulotomy performed?

Since YAG laser capsulotomy is an outpatient procedure performed in clinic, you can eat and drink as normal. Use any regular eye drops as normal on the day of the treatment.

What can I expect after YAG laser capsulotomy?

  • Your vision will be blurry for two hours while the dilating drops wear off. You may need someone to drive you home.
  • You may notice new floaters (specks) in your vision, which will disappear over one week.
  • Vision is normally sharper by the following morning.
  • On the day of the laser you can do all of your normal activities, including exercise and swimming. There are no restrictions.
  • The lens capsule does not re-grow and you almost certainly will not need a repeat of the procedure.
  • You will be given anti-inflammatory eye drops to use for 1-2 weeks.

Are there risks of having YAG laser capsulotomy?

All medical procedures carry some risk, although fortunately the risks of laser capsulotomy are very small. Below are the key risks you need to know:

  • Transient floaters in the vision for approximately one week. These are rarely bothersome.
  • Minor eye inflammation and redness. To prevent this, I proactively give all of my patients anti-inflammatory eye drops to use for 1-2 weeks.
  • A transient rise in eye pressure. This is rare, and tends to only occur in patients who have advanced glaucoma (the disease of elevated eye pressure).
  • Laser damage to your intraocular lens. This is extremely uncommon with modern lasers operated by ophthalmologists who are experienced with the procedure. Regardless, small marks on the lens do not tend to affect vision.

Retinal tears (a break in the camera film that lines the back of the eye). A retinal tear may cause you to see flashing lights in your vision, or a shower of new floaters. The risk of a retinal tear following laser capsulotomy is very small (<1%) and the risk is even lower if the capsulotomy is delayed more than 6 months after cataract surgery

What if I don’t have a YAG laser capsulotomy?

Although a YAG laser capsulotomy is an elective procedure, it is highly recommended. With PCO,your vision will continue to get blurrier over time. YAG laser capsulotomy is considered very safe and the are no alternatives for treating PCO.

Please do not hesitate to contact my office if you have further questions regarding posterior capsule opacity or YAG laser capsulotomy.


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Monday to Friday: 8am – 4.30pm

Dr Nick Andrew

Ophthalmologist and Eye Surgeon Gold Coast

Sight Specialists, Level 2, 95 Nerang St, Southport QLD 4215

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