Cataract

Quick Facts: CATARACT

Early: NO SYMPTOMS

Later: VISION BECOMES CLOUDY, SENSITIVITY TO LIGHT, FIND IT DIFFICULT TO SEE IN BRIGHT LIGHT, TROUBLE SEEING AT NIGHT, DIFFICULTY SEEING WELL ENOUGH EVEN WITH GLASSES, IN SOME PEOPLE VERY “THICK” CATARACTS UNTREATED FOR A LONG TIME CAN CAUSE ACUTE GLAUCOMA WITH HIGH EYE PRESSURE

Who is at Risk: AGE > 40, DIABETES, PREVIOUS EYE INJURY, USE OF STEROID MEDICATIONS, PROLONGED EXPOSURE TO SUNLIGHT ESPECIALLY WITHOUT SUNGLASSES

Did you know?

Singapore, cataract affects around 80% of people aged 60 and above in Singapore and is the most common cause of blindness in the world.

1. Cataracts are very common and will affect most people at some point in their lives. By age 80, most people would either have cataracts or have had their cataract surgery done.
2. Cataract surgery is the most common operation performed in Singapore.
3. Cataract surgery can potentially correct your “degree” and provide relatively spectacle free vision in a selected group of patients.

What is Cataract?

In all our eyes, there is a natural lens. This lens is responsible for focusing light entering the eye on the retina so we can see well. To do this, the lens needs to be clear.
A cataract is when our lens has become cloudy. This causes our vision to become hazy and blurry, similar to looking through a fog or dirty windscreen of a car.

What are the symptoms of Cataracts?

You may experience:

• Blurry vision
• Double vision
• Extra sensitive to light: experiencing glare when looking at bright lights or in daylight
• Difficulty seeing well in dim lighting
• Colours appearing faded or taking on a yellow tint

What is the treatment for cataracts?

• Environmental: if you have early cataracts, you may be able to manage by doing the following:
  • Increase the lighting at home and at work
  • Wear sunglasses to reduce glare
  • Get a new pair of glasses: when cataracts occur, they can cause a shift in the focusing power of the eye. Changing your glasses may help to improve your vision in the initial stages of a cataract.
• Surgery may be offered when:
  • Blur vision is affecting daily activities such as driving, watching TV, enjoying certain hobbies and even work.
  • Glaucoma or other eye conditions may benefit from removal of the cataract and becomes part of the treatment for the eye condition or help in monitoring the condition because the cataract is preventing a clear view of the internal structures of the eye.
  • Spectacle-free lifestyle choice is desired: sometimes the presence of a cataract presents an opportunity for us to correct both the blurring of vision caused by the cataract and the blurring of vision caused by short-sightedness or long-sightedness, astigmatism and  presbyopia (or “lao hua” – in Singapore local parlance). This offers the opportunity to see for most situations without spectacles.

What happens in cataract surgery?

Cataract surgery is performed as a day surgery case in the operating theatre, so you will not need to stay in hospital normally. The surgery will usually take less than 30 minutes although this may vary depending on the complexity of the cataract surgery.

Cataract surgery is not painful as you will be given anaesthesia around the eye. This reduces the need for general anaesthesia where you will be put to sleep. Most patients are awake during the operation and may be given some sedation to reduce anxiety. The combination of anaesthesia to the eye and sedation allows for cataract surgery to proceed very comfortably for almost all patients. In some special situations, general anaesthesia may still be considered.

4 basic steps in any cataract surgery

1. 1. Gaining access to the cataract
      • This will involve making a small entry point in the transparent surface of the eye called the cornea to enter the eye.
      • Circular opening is then made in the front surface of the natural lens bag to allow access to cloudy cataract in the lens bag
   2. Removal of the cataract
      • Phacoemulsification: currently, most of cataracts are removed with the use of this ultrasound-based technique where ultrasound energy is delivered through a pen-like handpiece to remove the cataract bit by bit in a smooth and controlled fashion. Usually no stitching of the entry wound is required because only a very small entry wound is needed for the handpiece. This has the advantage of faster healing and earlier recovery of vision as stitches and larger wounds cause more astigmatism.
      • Extracapsular manual technique: this involves manually easing the cataract out of the eye through a larger wound. This technique is less commonly used nowadays but still has a role for very thick and dense cataracts as the ultrasound in phacoemulsification may not be possible to perform safely without significant risks. The disadvantage is that it involves a larger wound and will require stitching. The combination of a larger wound and stitching will mean a longer time to visual recovery and the possible requirement of removing stitches at the clinic later. That is why we advice our patients not to wait too long in having their cataracts removed, because when a cataract becomes too thick after waiting a long time.
   3. Placement of an artificial lens implant called the intraocular lens implant
      • After your cataract has been removed, what is left is the empty lens bag.
      • The removal of your natural cloudy cataractous lens needs to be replaced by a lens implant, otherwise you will not be able to see without very thick glasses

What happens after cataract surgery?

• A shield will be placed over your eye to protect it while you heal from surgery.
• You will rest in a recovery area. Then you will be ready to go home.
• You will have to use eye drops after surgery.
• Avoid getting soap or water directly in the eye.
• Do not rub or press on your eye.
• Initially, you may take a little time getting used to the brightness of your vision after cataract surgery. You may find it useful to wear sunglasses to help with this.
• You will need to wear a protective eye shield when you sleep for the first week in most cases, we will advice you accordingly.
• You should expect to be able to resume normal activities like driving and exercise after a week in most cases. In some cases, this may take a little longer and we will advise you accordingly.

Intraocular lens implant: the replacement lens after removal of your cataract

The intraocular lens (or IOL) is the artificial lens that replaces the eye’s natural lens which is removed during cataract surgery.

This IOL is made of medical grade silicone, acrylic, or other plastic compositions which can remain inert in the eye without causing inflammation or other problems.  The IOL has a long history and dates back to the second world war when Sir Harold Ridley discovered that shattered windscreen from fighter planes embedded in the eye of  pilots did not cause any infection or inflammation for years.

Because of this, the IOL is good for a lifetime and will serve its function of providing focusing power for your eye to see clearly for a lifetime without the need for replacement.

The IOL is also designed to be placed inside the natural pocket or lens bag of the eye and remains very stable without shifting or displacement in almost all patients. Of course, in a very small minority of us, the IOL can shift in position, but this is very rare.

Correcting different refractive errors (“degree or power” of your spectacles) through cataract surgery

There are 3 types of refractive errors or “degree” that cause blurring of vision:

1. Myopia or Hyperopia: which is short-sightedness or long-sightedness which causes blurring of vision when looking at distant objects.
2. Astigmatism: which is an irregularly shaped cornea also causing blurring of vision when looking far.
3. Presbyopia: which is difficulty focusing for near objects, this usually begins to set in from age 40 requiring reading glasses to help us see well for near.

The correction of these refractive errors through cataract surgery is achieved through 2 ways:

1. Implantation of specific types of intraocular lenses to achieve the required vision needs.
2. Targeting specific “degrees” after cataract surgery
   1. For example, in monovision, one eye is operated to achieve very good distance vision while the other eye is operated to leave a small amount of short-sightedness to help with reading or intermediate distance vision.

The types of intraocular lenses available as follows:

1. Monofocal IOLs: these are the most used. “Mono” meaning single, so monofocal means single focus lenses where the implanted lens is usually only able to focus either for far or for near. These lenses can only correct short-sightedness or long-sightedness. They will not be able to help with astigmatism or presbyopia (“lao hua”).
2. Toric IOLs: these lenses function like a monofocal IOL by correcting your short-sightedness or long-sightedness. They also have the added benefit of correcting your astigmatism. If you have astigmatism and use only monofocal IOLs, you may still need glasses for distance vision after your cataract surgery. The use of toric IOLs when you have significant astigmatism can help provide clearer vision for distance and may even offer spectacle-free distance vision in some cases.

3. Multifocal IOL: these lenses have the ability to provide focus for far as well as near. These lenses are a possible option if you are are very keen to not have to wear glasses most of the time. However, it is important to understand that they do not totally replace the need for reading glasses, especially for extended periods of near work such as reading a book for more than an hour.
   Multifocal IOLs are also “not a perfect solution” .  There are some “trade-offs” in exchange for being relatively spectacle free.

   What are these “trade-offs”? Namely:

   • Glares, haloes and starbursts: these visual symptoms are most pronounced at night when looking at a point source of light.. An example will be when driving at night and facing an oncoming headlight. (See image below)
     • Glare is a blurring or smearing of lights
     • Haloes are distinct rings around lights
     • Starbursts appear as rays of streaks coming from lights
   • Vision in the night or dim lighting may also be less clear

Multifocal IOLs are also “not a perfect solution” .  There are some “trade-offs” in exchange for being relatively spectacle free.

What are these “trade-offs”? Namely:

• Glares, haloes and starbursts: these visual symptoms are most pronounced at night when looking at a point source of light.. An example will be when driving at night and facing an oncoming headlight. (See image below)
  • Glare is a blurring or smearing of lights
  • Haloes are distinct rings around lights
  • Starbursts appear as rays of streaks coming from lights
• Vision in the night or dim lighting may also be less clear

In spite of these trade-offs, carefully selected patients who have cataract surgery with multifocal IOLs have a high degree of satisfaction and are very happy with being able to see both far and near without the need for glasses most of the time. The

5. Multifocal Toric IOL: this is an “all-in-one” IOL which corrects short-sightedness or long-sightedness, astigmatism and presbyopia (or “lao hua”).
6. Extended Depth of Focus IOLs (EDOF): these lenses also provide an extended range of vision allowing for some near vision, so is similar to multifocal IOL. The difference lies in the way this is achieved. EDOF uses a different lens design to help provide some degree of reading vision but may not be able to achieve as good near vision as multifocal IOLs. In return for less strong reading ability, the EDOF lenses may have less glare and halo side-effects.

So cataract surgery is increasingly becoming more individualised because of the range of options for achieving different vision needs. We need to take into account different factors such as your occupation and your hobbies, how often you drive at night and whether you read a lot or work on the computer a lot, even the length of your arm to determine what your reading distance is before deciding which implant and what type of outcome will suit your requirements best.

What are the risks of cataract surgery?

Modern cataract surgery has a good track record with a success rate of up to 98%. However, any surgery will have some risks. Here are some of the risks:

1. Infection: this is very rare and occurs in less than 0.1% of all cataract surgeries performed.
2. Bleeding in the eye: this is also very rare and occurs in 0.03% to 0.1% of cataract surgeries.
3. Swelling of the front or back of the eye: this may occur and, in most cases, settles down after treatment.
4. Retinal detachment: Individuals with high myopia are at slightly increased risk of developing a retinal detachment, a condition which will need laser treatment or further surgery.
5. Raised pressure in the eye: This may give rise to headache or eye pain, and almost always
6. responds to eyedrops, tablets or an injection.
7. Damage to the lens membrane called Posterior Capsule Rupture (PCR): The empty membrane or “skin” of the cataract is always left intact in the eye, so that the artificial lens can be placed within it. However, this very thin, fragile structure can be damaged in 1-2% of cases, usually without any impact to vision. Very rarely, pieces of the cataract may slip through to the back of the eye; an additional surgery will then be required to remove them. This will incur some extra cost.
8. Posterior Capsular Opacification (PCO): this is what is often referred to as a “secondary cataract” or the “return of cataract”. In fact, once your cataract has been removed, it will never return. In PCO, what has happened is a membrane called the posterior capsule becomes cloudy. It might help to think of the posterior capsule as a transparent pocket. It used to hold your natural lens which was removed during cataract surgery and now holds your new intraocular lens in place. If you notice cloudy vision again, you might need to have a laser procedure. The laser creates an opening in the cloudy capsule and is called a posterior capsulotomy (or a YAG laser capsulotomy). This procedure helps restore clear vision and is a very quick treatment that is done in the clinic with no down time.

Cost of Cataract Surgery

Cataract surgery is a medical treatment that is eligible for Medisave use. The amount that can be used is $2450. This can either be from your own medisave account or your next-of-kin’s account.

https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/age-related-macular-degeneration

https://www.aao.org/eye-health/diseases/amd-treatment

The symptoms and possible related eye conditions/diseases in this section are for general reference only, and do not contain all visual symptoms or all possible related conditions or diseases. If you have any unusual vision symptoms, speak with your ophthalmologist.