Stephen Lash Eye Surgery
The stages of cataract surgery.
Imagine the cataract as a milk chocolate smartie. It has a capsule (The coloured part of the smartie) and the cataract/lens centre (The milk chocolate).
1. Two flat cuts are made in the cornea (The clear front of the eye) by the pink blade. One larger one and a side port. Both seal without sutures.
2. VIscous fluid is injected into the anterior chamber (The front chamber of the eye in front of the lens). This flattens the lens surface to help make a circular hole in the capsule (coloured coating of the smartie) easier.
3. An orange needle curved at the tip cuts from the centre of the lens capsule out to one side and a flap is lifted and peeled in a circle.
4 Some fluid id injected under the edge of the capsule to separate the milk chocolate (Lens) form the coloured coating (Capsule) of the smartie. The lens (Milk Chocolate) will now freely rotate inside the capsule (The coloured coating)
5 The ultrasound probe is place through the larger cut and the second instrument is introduced. This is called a chopper and it is designed to curve around the lens (Milk Chocolate) under the capsule (The coloured coating)
6. The lens is chopped into four pieces like a trivial pursuit counter. The chopper is curved around the lens under the capsule and then the ultrasound probe is buried into the lens. The chopper is brought towards the probe and the lens chopped in half and then quarters. Each piece is then dissolved with ultrasound and sucked out of the eye
7 This leaves the capsule with a thin layer of soft lens matter which is sucked out of the eye by the flat looking instrument (A simcoe)
8 The now empty capsule (The coulored coating now devoid of milk chocolate) is inflated with the same viscous fluid used at the beginning. This creates the space for the new plastic lens
9 The new plastic lens is injected into the capsule and slowly opens (Very slowly in this case!!) It is rotated into place.
10 The thick fluid is sucked out and the the chamber is re inflated.
11. Job done now onto the vitrectomy in this case! (Hence the three yellow things)

Cataract Surgery (Phacoemulsification)

What is cataract?

It is best to think about the lens as a ‘Smartie’ sitting behind the coloured part of the eye (The iris). A smartie has a coloured coating and a milk chocolate centre, the lens has a clear coating (The capsule) but the milk chocolate centre (the substance of the lens) becomes cloudy (Cataract).

There are several different forms of cataract from a generalised clouding of the lens as seen in older age through to the posterior subcapsular cataract (clouding of the lens just at the back part) seen in younger people, which tend to progress rapidly. We even see the appropriately named ‘Christmas tree cataract’ with beautiful multi-coloured facets. Cataracts can also result from trauma and surgery to the Jelly of the eye (Vitrectomy) and some people are born with cataracts but have no problems with their sight whilst some children require cataract surgery soon after birth (But not by me!).

How do they interfere with sight?

Cataracts may cause blurred vision, glare, ghosting and haloes and can change the power of the eye making it see better for close up work. They also change the way the eye sees colour with blue light especially fading over the years as Monet found out.

If you want to be very pessimistic then cataract starts just after birth! The lens continues to grow throughout life getting harder and harder so that children can read on the end of their nose but the 50 year old can’t read at the end of their arms! This is a normal aging process and the onset of trouble with near is called Presbyopia. As the lens continues to harden it can become cloudy hence the diagnosis of cataract. It is not a skin over the eye and this misconception probably comes from seeing the very dense white appearance in the pupil of the eye seen in very advanced cases in the third world.

How do you take out the cataract?

Whatever the type of cataract the surgery is the same. The aim is to remove the milk chocolate (The cataract) and leave the coloured coating (The capsule) intact so that a new plastic lens can be placed within. The capsule is securely fastened to a ring of muscle by millions of tiny threads (The zonules) and in most cases these are strong enough to support the plastic lens but in trauma (see video in trauma section) they may not!

When should I have surgery?

You only really ‘need’ to have your cataract removed when you cannot see well enough. Most people ‘want’ to have their cataract removed much earlier than this although NHS thresholds are generally moving towards worse vision before surgery can be performed. Some people ‘desire’ to see without spectacles and will have surgery even without any significant cataract (Refractive Lens exchange). We do not really talk about 'Ripe!'

Nobody would jump out of a second floor window. If a lion walked into the room most people would jump out of a second floor window. As it is with consent for surgery. If the cataracts bother you then it is worth contemplating surgery, if not there is no need. If you are a driver then it is best to check vision on a number plate test and consider surgery before this level of vision is in danger.

Surgery has low complication rates and results are usually excellent. There is a 1 in 1000 risk of loosing sight from an infection and less than 2% risk of a variety of minor complications such as rupture of the capsule, raised pressure and swelling of the retina which usually cause the surgeon more concern, vision is usually good even after these minor complications.

Surgery is performed with an anaesthetic drop in the eye with the anaesthetic topped up inside the eye during surgery. It is not at all painful but if the light seems too bright an injection of anaesthetic can be slipped around the back of the eye to improve comfort. You will lay flat for around 20 minutes and be covered by a drape. The lids are held open by a small speculum which is a little clip that spreads the lids. I will ask you to look at a light and, if you want me to, talk you through the procedure. I like theatre to be relaxed with music in the background. Sedation is usually not required and you can return home after a cuppa! Recovery of vision is usually rapid over days and becomes stable after 6 weeks. Both eyes can usually be done from a week apart to years later.

What lens do you put in?

This is where it gets interesting. Currently on the NHS, very good quality single vision lenses are put into the coloured bit of the smartie, we call it 'the bag'. A single vision lens will focus you at a single distance. Usually most people want to be able to see in the distance and so I aim for this. Just like there is no perfect shoe for your foot, there is no perfect lens for your eye, they come in steps of power and I will choose the closest power to zero so that the lens should enable you to see clearly in the distance.

If you have astigmatism (An eye which is rugby ball shaped rather than football shaped) lenses are available to correct this. These lenses are known as toric lenses and can be used in a single vision lens or in a multifocal. Astigmatism is not always bad and can facilitate reading vision with a distance lens giving a degree of multifocality.

If you fancy being a 'Jack of all trades and master of none' you can opt for monovision. Here I would put a standard lens in the dominant eye for distance and leave you a little bit shortsighted in your other eye enabling you to read with this eye. In this way, with both eyes, you can see well in the distance and also see for reading. This should give you about 80% of visual tasks without spectacles although you may need readers to read a book in dim light or you may prefer to boost distance vision in your reading eye for driving. Its a really simple and really good option for many people.

A step beyond this is the multifocal lens which gives you clear distance and reading vision in the one eye with the one lens. They sometimes result in glare and haloes which most people can ignore (but not all) and each generation of lens is getting better and better with far less glare and haloes than before. My current choice of lens is the Symphony lens which is an extended range lens and although all patients get haloes they are predictable and do not seem to bother them. Please read my Information Leaflet on these lenses as expectations are critical!

Personal Multifocal leaflet.pdf Personal Multifocal leaflet.pdf
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