What is a Cataract?

What age do cataracts develop?

Cataract Surgery

What can go wrong?

I don’t have cataract: Can I have this surgery to correct my vision?

I’m getting old and hate wearing reading glasses

What types of intra-ocular lens implants are available?

What is important about Asphericity?

I have Astigmatism, can this be corrected?

I’ve had laser surgery, can I still get a good outcome?

Other Conditions

Find out more about other conditions including Glaucoma and Macular Degeneration.

The History of Cataract Surgery

Professor William Ayliffe FRCS PhD – Gresham College Lectures

What is a Cataract?

Diagram of the process

Cataract is a clouding of the crystal lens of the eye behind the pupil. In the early stages it may not cause any bothersome symptoms and just an update in spectacles will suffice.

As time progresses symptoms including glare, blurring and difficulty reading or driving, particularly at night require intervention.

High magnification pictures of cataract showing the clouding in the pupil and the view with a slit lamp showing the yellow-brownish opacity in the crystalline lens behind the pupil.

Currently the only effective treatment is to remove the opacity via a tiny 2mm incision and replace the cataract with a clear plastic lens.

What age do cataracts develop?

Generally, cataracts are an almost inevitable condition of aging. In our modern society dependent on fine visual tasks such as driving or using computers, symptoms cause problems at an earlier stage than in pre-industrial agricultural societies.
However babies may be born with cataracts, children may get cataracts from eye diseases such as uveitis or trauma, and young people may rarely develop cataracts that require removal.

There are different types of cataract and several systemic diseases and medications can also lead to cataracts developing.

Cataract Surgery

With age, disease or trauma the optical clarity of this lens becomes compromised.

With age, disease or trauma
the optical clarity of this lens
becomes compromised.

We aim to make the surgery as comfortable as possible but also safe and effective.

  • The procedure is performed as a day case and most patients chose to leave the hospital a few hours afterwards, wearing a clear shield.
  • The vision remains blurry for the rest of the day because the pupil is dilated.
  • You will be greeted by the reception staff and taken to your room, where the eye will have drops put in.
  • You will be collected a little later and taken to theatre.

In the preparation room you will have local anaesthetic drops and iodine instilled. There are no needles and you will not feel any discomfort. Some patients opt for sedation which is always available if requested.

Once in theatre you will hear some music playing whilst the team checks your identity, the type of operation and which side is to be operated. The surgeon rechecks the calculations and checks the type and power of the lens with the team.

1: Preparing for removal by making a circular aperture in the capsular bag stained blue.

2: Insertion of the lens

3: Lens sitting securely in place seconds after surgery is completed.

The surgeon uses a microscope to ensure the procedure is completed safely.

Before you know it, you will be on your way back to enjoy a well deserved snack and drink. Following cataract surgery you will wear the shield at night for the first few days, and instill drops four times a day for two weeks, reducing to twice a day for the subsequent two weeks.

Your eyes will be checked in outpatients during this period. We advise no strenuous exercise or bending over and unusual head positioning for 3 weeks after the operation to ensure the lens fixes in the correct position.

It is unwise to swim or expose the eye to unclean water for at least 2 weeks post operation to prevent the risk of infection. You may fly, walk, drive, use the computer and undertake routine chores on the day following surgery. If in any doubt about an activity do not do it until you have taken advice from the team.

What can go wrong?

The procedure is tremendously successful in experienced hands with over 96% of patients getting an outstanding visual outcome.
Nevertheless, as in all surgery, problems can happen and the expected outcome is not achieved. However, in cataract surgery with highly experienced surgeons this is most unlikely.

The most frequent of these rare problems are visual such as temporary glare and semicircular edge effects. These nearly always settle without treatment within a few weeks. With certain types of lenses such as multifocal they may be more persistent and for that reason those who need to drive a lot at night may not be candidates for certain lenses.
A very people do not get such excellent vision without glasses for a variety of reasons, including pre-existing disease (such as glaucoma or macular degeneration) or due to errors in the measurement, which require spectacles, or extremely infrequently, replacement of the lens or laser surgery to correct.

Uncommonly, and mostly in short-sighted people, the retina at the back of the eye may detach requiring surgery to refit it in place.
One in 2,000 cases can get infection or haemorrhage which is more serious and requires specialist management.

I don’t have cataract: Can I have this surgery to correct my vision?

The same procedure used to remove the crystalline lens of the eye which has no opacity, is called clear lens extraction. A number of different names are occasionally used by some companies to market this procedure.

For most long-sighted and short sighted people, even those with astigmatism, having laser by our expert team is by far the better optical and safest surgical approach to dealing with the problem. Our laser is able to correct more types of problems than most other technologies commonly used in the refractive market.

However for the very few who are not suitable for laser then clear lens extraction provides an effective but more invasive solution.
The pros and cons of this will be discussed at length in your consultation.

I’m getting old and hate wearing reading glasses

Whilst many companies will recommend clear lens extraction, our experience has shown that presbyopic laser treatment remains the most effective and safe way to manage your reading needs.

You will be assessed to exclude any eye disease and referred to our specialist laser surgeons if you wish to proceed.

What types of intra-ocular lens implants are available?

We currently offer a wide variety of lens implants. These include hydrophobic aspheric, spheric, astigmatic (toric) and extended focus (multifocal and symfony®)
Hydrophobic acrylic is the best material with unrivalled long-term stability and clarity.

What is important about Asphericity?

All convex spherical lenses focus light. However the light from the edges comes to a focus in front of the focus plane from those rays passing nearer the centre causing a blurred focus.

The cornea of the eye also has spherical aberration, but this is corrected by the crystalline lens of the eye having opposite neutralising aberrations.

The problem comes if we replace this lens with a spherical lens. The aberrations add up and produce an image for the retina that is not as sharp as that formed by neutralising aspheric lenses such as those we use in our clinic.

I have Astigmatism, can this be corrected?

Yes, using special toric lenses most patients with regular astigmatism can be corrected. You will have some extra tests and calculations to determine exactly which lens best suits your eyesight.

I’ve had laser surgery, can I still get a good outcome?

After laser refractive surgery, the shape of the eye changes. This makes calculations a little more uncertain. However, with over 20 years of experience in dealing with these eyes we have developed robust algorithms to reduce this variability.

Some patients will have the asphericity of the cornea altered by the procedure and require spherical-type lens implants.