YAG Laser Capsulotomy

Learn the most important facts about YAG laser capsulotomy in this complete guide.

YAG laser capsulotomy

YAG laser capsulotomy is a procedure to treat a frequent occurrence in the healing process of cataract surgery: posterior capsular opacification (PCO).

One of the most common events after cataract surgery is posterior capsule opacity. This opacity is also called posterior capsule opacification, or posterior capsular opacification, PCO.

PCO is a whitening, thickening or opacity of a thin membrane (the capsule) that is just behind the new intraocular lens implant (IOL). PCO clouding does not hurt the eye, but it can reduce vision to the same extent or even worse than the original cataract. It can occur several months or years after cataract surgery, although PCO most commonly occurs about two years later.

When the surgeon removes the natural lens during cataract surgery, he or she leaves the thin clear bag surrounding it in place; this bag is called the capsule. It is used to house the new IOL implant. Some lens cells that lived on the capsular bag are usually left behind, and these cells can induce a kind of scarring that turns the transparent membrane white or cloudy.

This opacity is part of the healing process and will usually cause a gradual loss of vision after surgery. This posterior capsule opacification (PCO) can be treated successfully with a one-off minor laser treatment called YAG capsulotomy.

Cataract surgery complications

PCO is considered a normal result of healing after cataract surgery. However, other issues can be true complications and are fortunately rarer; hence cataract surgery is considered as one of the most successful surgical procedures in routine use around the world.

The UK National Health Service (NHS) performs over 300,000 cataract extractions each year. Additionally, private hospitals and facilities increase that total to around 400,000 annually. American surgeons carry out relatively many more cataract operations (approximately 3,000,000 each year) with a reported success rate of 98 per cent or higher.

Research on over 220,000 US Medicare cataract surgery patients over twelve years (1994-2006) discovered that an impressive 99.5% of patients had no severe postoperative complications. Also, the chance of severe complications has declined with developments in surgical instruments and techniques.

Potential cataract surgery side effects include:

  • Inflammation inside the eye
  • Photopsias (perceived flashes of light)
  • Dislocation of the intraocular lens (IOL)
  • Macular oedema (swelling of the central retina)
  • Droopy eyelid (ptosis)
  • Sensitivity to light
  • Raised pressure in the eye (ocular hypertension)

When complications from cataract surgery do happen, most are minor and can be successfully treated either medically with eye drops or tablets, or with additional surgery.


What is posterior capsular opacification?

Sometimes posterior capsular opacification is incorrectly referred to as a “secondary cataract.”

However, PCO is not an actual cataract because once a cataract is surgically removed, it cannot return. The transparent natural lens that transformed into a cloudy cataract is gone.

During cataract surgery, your specialist will remove the cloudy lens inside your eye and replace it with an intraocular lens (IOL). The doctor makes a hole in the capsule surrounding the lens to access the cataract.

This clear bag, known as the lens capsule, remains in place. Apart from the hole in the front surface, the capsule is otherwise intact and can be used to make a home for the new implant.

The surgeon implants the IOL implant inside this empty bag, which helps it remain in the correct place inside the eye. After cataract removal, the capsule and IOL are both transparent; hence your vision should be clear. It may take a few days, occasionally weeks, for your eyesight to fully settle.

However, in around 20 per cent of cataract surgery patients, the rear (posterior) portion of the capsule becomes whiter, hazy or opaque sometime after cataract surgery, giving us the term Posterior Capsular Opacification, or PCO for short. PCO can happen months or, more commonly, years later.

lens anatomy PCO

What causes posterior capsular opacification?

Posterior capsule opacification occurs because lens epithelial cells (see above image) and other cell types remaining after cataract surgery have grown on the capsule. Having some lens cells appears to be essential to maintaining the strength of the remaining bag, but they can also induce an unwanted opacity and loss of vision.

In some cases, if posterior opacification progresses significantly, your vision may be worse than it was before cataract surgery.

PCO is also more common in certain situations, such as where inflammation (swelling) is present in your eye or if someone has the genetic eye condition retinitis pigmentosa. However, it’s not unusual to develop PCO even if you don’t have these eye conditions.

In some cases, if posterior opacification progresses significantly, your vision may be worse than it was before cataract surgery.

YAG laser treatment for PCO

In 1980, Daniele S. Aron Rosa, MD, presented the use of a specific type of laser as a treatment for PCO. She had performed the first such procedure in January 1979.

The device in question is called a Nd: YAG laser, often shortened to YAG. It uses neodymium-doped yttrium aluminium garnet, a type of crystal used to create the energy beam for solid-state lasers.

Before the development of YAG laser capsulotomy, patients would need an operation known as a surgical discission. The surgeon used a knife to cut an opening in the posterior capsule, which improved vision. However, it was associated with complications such as endophthalmitis and vitreous loss. The latter is where the jelly inside the back part of the eye can bulge forward into the front of the eye.

YAG laser treatment video

The following video courtesy of the American Academy of Ophthalmology describes the benefits, procedure and risks of YAG laser capsulotomy.


Click here to book a YAG capsulotomy consultation with our friendly team. We can advise you on the right procedure.

How common is posterior capsular opacification?

Various researchers have looked at the incidence of posterior capsule opacification. According to an analysis published back in 1998, a quarter of patients developed significant PCO within five years of the procedure. Furthermore, in 1983 it occurred after almost 30% of cataract procedures.

More recent studies showed the incidence of PCO has fallen in the first few years after surgery. A recent UK study showed a range of occurrence of PCO from 7% to 22% at five years after cataract extraction.

YAG laser capsulotomy is a procedure to treat the most common complication of cataract surgery: posterior capsular opacification (PCO).

Article Authors
Publisher: London Cataract Centre
Minita Shah optometrist
Minita Shah
Samer Hamada surgeon
Samer Hamada MD
Consultant Surgeon

How many cataract patients need YAG?

As time passes, more and more patients will need to have their capsular opacification treated. As such, the cumulative incidence of YAG capsulotomy to address PCO increases each year after cataract surgery:

  • 10.6% after one year
  • 14.8% after two years
  • 21.2% after three years
  • 28.6% after four years

However, newer technologies and surgical approaches may only have delayed the onset of capsular opacification. The incidence may still likely be around 20% by 5-7 years post-op, with some surgeons saying it can rise much higher if you reassess some years down the line.

Fortunately, there is a quick and effective treatment using a YAG laser—more details below on the actual procedure.

YAG by year postop cataract surgery

Risk factors for capsular opacification

Several known risk factors will increase your chance of developing PCO, which include:

  • Being younger than 60 years of age
  • Diabetes (which also can lead to other eye problems)
  • A hard, dense cataract which takes more energy to remove
  • Not having phacoemulsification
  • Surgery after vitrectomy (removal of the vitreous gel)
  • An IOL implant that is “hydrophilic” (binds better to water)

Being younger is a known risk factor for PCO. Young people have more lens cells than older patients, and these cells are capable of multiplying to a higher degree. Plus, the levels of various hormones and cytokines in the fluid inside younger eyes aid these cells to grow and spread, leading to capsule opacification.

Research studies showed that the rate of lens cell growth in young patients (younger than 40 years of age) is three times faster than in patients who were older than 60.

Fortunately, there is a quick and effective treatment FOR PCO using a YAG laser

YAG laser procedure steps

Fortunately, a YAG laser can treat posterior capsule opacity safely, effectively and painlessly. This procedure, known as YAG laser capsulotomy, often can be performed in your doctor’s office.

YAG laser posterior capsulotomy effectively reverses the drop in vision caused by PCO. Additionally, YAG laser treatment leads to an improvement in glare symptoms and contrast sensitivity.

Please note:
Your vision will be checked before the YAG procedure. Please bring your glasses with you to the appointment. Also, clinic staff will put drops in one or both eyes to dilate your pupils but which will blur your vision for several hours afterwards. Special preparations such as fasting or changing into operating theatre clothes are not necessary.
YAG laser PCO capsule examination
YAG laser capsulotomy can be completed in a few simple steps:

Before the procedure, the nurse will dilate your pupil/s using eye drops, such as tropicamide (you may have both eyes dilated). You will also have an anaesthetic drop to numb the surface of the eye. You will sit at a small desk with an upright microscope called a slit lamp, and the YAG laser is part of this microscope. You must remain still during the procedure.

Your surgeon will then focus the laser exactly onto the back of the lens capsule. Once in focus, he or she will use the YAG laser to quickly remove or open the cloudy capsule behind the lens implant to clear the obstruction from your line of sight. A contact lens may be inserted to assist in focusing the laser onto the capsule and to help keep your eye from blinking. There is no need for an incision or to touch your eye (unless using a contact lens).

Ophthalmologists usually will advise the use of anti-inflammatory eye drops after the YAG laser procedure. Typically you will be given drops to use four times a day for a week after treatment. After completion, you will return to the lounge area.

Your doctor or nurse may check the pressure inside the eye about one hour later. If this occurs, you may need additional treatment before you can go home. This process should take a few hours at most. Furthermore, he or she will examine the eye to confirm that the hole is in the correct place within the capsule, and no further YAG laser treatment is needed. If this is the case, it will be necessary to repeat the procedure at a later date.

Your YAG procedure

The whole laser process takes just a few minutes; you should feel no pain at all. You will hear some beeping noises from the laser and can experience bright lights. Further, after the treatment, you should experience no discomfort. The laser uses light of a wavelength that the human eye cannot see, but you may notice a small red light, which the doctor uses to focus the laser beam.

While most people are suitable and very capable of remaining still, some uncooperative patients, e.g. children and mentally disabled patients, may need sedation to make the laser procedure possible.

If you would like to watch what actually happens during the use of the YAG laser, seen through the microscope, click on the video play button.

What happens after YAG capsulotomy?

There is no requirement for down-time after YAG capsulotomy; you may return to your normal activities following treatment, including swimming. However, immediately after the procedure, your eyes will still be dilated, and your vision may be blurry for a few hours. You will need to avoid being behind the wheel of a car until this blurriness has resolved.

By the following day, your vision is usually better than before surgery, although it can take several days to improve sufficiently.

You should not drive yourself home after the treatment. It can take some hours for the drops that dilate your pupils to wear off, and hence your vision may still be blurry following YAG laser treatment. You should arrange for someone else to drive you home after your YAG treatment, or plan to get home by public transport.

Floaters after YAG capsulotomy

You may notice some floaters afterwards, which are small dark objects that waft to and fro within your vision.

Floaters are harmless, made of clumps of collagen strands which drift around inside the vitreous (a jelly-like material which fills the inside of your eye). You may experience floaters in a variety of ways, e.g. as small dots, circles, clouds, lines or cobwebs.

Most people who are middle-aged or older will have experienced floaters, which are a normal part of ageing. Floaters are also more common in short-sighted patients, where they often will come on at a younger age.

Such floaters after YAG laser capsulotomy will often resolve within a few days, occasionally one or two weeks.

Most people should see their vision improve within 24 hours. As with any eye procedure, however, contact your ophthalmologist without delay should your vision deteriorate or show no improvement.

Will I need YAG treatment again?

The capsule cannot regrow and it is very unlikely you will need further treatment.

The surgeon uses the YAG laser to remove the central area of the cloudy posterior capsule. This capsule cannot regrow, and so the problematic drop in vision cannot return.

Only a single laser treatment is usually needed to permanently correct any reduction in eyesight from PCO following cataract surgery. The opened capsule will retract out of the way, clearing your line of sight.

However, if the capsulotomy opening is not of sufficient size, it may need to be repeated. The nurse or doctor will check the capsulotomy opening before you leave the eye clinic, and ensure that the new opening is sufficient.


Click here to book a YAG capsulotomy consultation with our friendly team. We can advise you on the right procedure.

Complications of YAG capsulotomy

YAG laser capsulotomy is generally a very safe and effective procedure

While YAG laser capsulotomy is generally a very safe and effective procedure, complications are possible. These include:

  • IOL (lens implant) movement and refractive change
  • IOL damage or pitting of the implant surface – the lens of the eye can be damaged by the YAG laser, leading to visual problems. In rare circumstances, the lens implant may dislocate or subsequently need to be changed
  • Inflammation (iritis)
  • Swelling in the cornea
  • Rise in eye pressure – the procedure may cause worsening of glaucoma or cause a transient elevation in intraocular pressure (IOP). Drops or tablets will treat this condition
  • Swelling in the retina (macular oedema) – the retina at the very back of the eye can become swollen, leading to blurry vision. This can be treated medically, although it can take many weeks to improve. The incidence of macular oedema after YAG laser capsulotomy is generally rare but is more likely in patients with diabetes
  • Retinal tear or detachment – the retina (the inner light-sensitive lining of the eye) can become detached. If this continues, it can lead to decreased or even a complete loss of sight. However, if a detached retina is detected early, it can usually be successfully repaired. The incidence of retinal detachment is, fortunately, extremely rare

There is evidence from research studies that lower amounts of laser energy for perhaps a smaller opening in the capsule may lead to fewer complications, including retinal detachment, rise in eye pressure, and even retinal swelling (macular oedema).

Do you need urgent treatment?

The following symptoms following your YAG capsulotomy mean that you need urgent assessment and possible treatment:

  • excessive pain
  • sudden onset of floaters (caused by small pieces of debris that float in the vitreous humour of the eye)
  • loss of vision
  • flashing lights
  • increasing redness of the eye

If you experience any of the symptoms listed above, telephone your specialist or clinic for advice immediately. If you cannot access your treating centre, you will need to visit your nearest accident and emergency department.


Click here to book a YAG capsulotomy consultation with our friendly team. We can advise you on the right procedure.

Are there alternatives to YAG laser?

The only alternative to a YAG laser capsulotomy is actually to do nothing. The capsule may or may not continue to thicken and opacify, and it will not cause any damage to the eye itself. If it does worsen, you may wish to consider having a YAG laser procedure in the future.

How do I prepare for YAG treatment?

Since this is a walk-in, walk-out procedure, you can continue to eat and drink. You should use any eye drops or other medications as usual on the day of the YAG laser treatment (unless advised otherwise).

If you decide to go ahead with a YAG laser procedure, you will be asked to sign a consent form.

Fortunately, a YAG laser can treat posterior capsule opacity safely, effectively and painlessly


Do I sign a consent for YAG capsulotomy?

If you decide to proceed with a YAG procedure, you will be required to sign a consent form. This form says that you agree to have YAG laser capsulotomy and you understand what it involves, including the risks and benefits.

Is PCO a complication?

No. It is a normal response as the capsular bag heals after removal of a cataract. The bag serves an important function to locate and fix the new lens implant (IOL) in position. It contracts like a shrink wrap around the lens. Over time, microscopic residual cells can proliferate and create scar tissue and pearly deposits over the posterior capsule.

Does my insurance cover YAG laser capsulotomy?

YAG may be covered by your health insurance plan. You will need to confirm with your insurer on the specifics of the policy. It is always a good idea to discuss with your clinic of choice as they likely have experience of dealing with insurance companies for the private cover of YAG treatments. They may be able to liaise on your behalf and arrange payment.

How much does YAG laser capsulotomy cost?

YAG laser treatment is typically around £500 per eye. YAG capsulotomy may be covered by your health insurance plan.

Does the NHS offer YAG laser treatment?

YAG surgery is certainly available on the NHS, for people whose vision and lifestyle are significantly affected by opacity of the lens capsule. Basically, the decision to undergo YAG capsulotomy is based on the same criteria as for cataract extraction:

  • Vision deterioration that is affecting work or other activities
  • Glare or dazzle induced by bright lights
  • Double vision (diplopia)
  • A significant difference in vision between the two eyes
  • Other vision-threatening eye problem/s needing visualisation of the inside of the eye

If your lifestyle is significantly affected by mistiness of the lens capsule, the NHS may offer YAG capsulotomy.

Lesya Zvarun

Clinic Manager

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