Cataract

When light enters your eye, it passes through the transparent window at the front of the eye (the corneal lens) and the natural lens inside your eye. Both lenses work together to focus the world on the retina (the light-sensitive layer of cells at the back of your eye). The eye’s natural lens sits just behind your pupil, which is the black circle in the centre of your eye.

Cataract is the term we use to describe the changes that occur when the lens of the eye loses its transparency and changes from appearing like a crystal clear window to appearing like a misted window like frosted glass. The most common cause of this change is age, and medications and conditions like diabetes can also contribute. Cataracts usually start to develop in a person’s lens as they age. The opacity in the lens stops some of the light reaching the retina. This opacity can affect your vision, making it increasingly cloudy, blurry, or misty.

Cataracts usually start to develop in a person’s lens as they age. They stop some of the light reaching the retina. This can affect your vision, making it increasingly cloudy, blurry, or misty.

Risk factors for cataract development include:

• diabetes or high blood sugar
• steroid use (tablets, creams or inhalers)
• ultraviolet light exposure (for example, sunlight)
• smoking
• eye diseases: uveitis, glaucoma
• trauma to the eye
• previous ocular surgery (for example, retinal detachment surgery)
• genetic predisposition

Cataract symptoms and lifestyle impacts
Cataracts often develop slowly and painlessly. They can affect your vision and ability to do day-to-day tasks without you realising it. We can sometimes correct this gradual decline in sight with an up to date pair of glasses. More often than not, the glasses prescription continue to change, and the new pair of glasses is very soon obsolete.

The most common signs of cataract are:

• frequent changes in the prescription of glasses
• changing reading vision – either worsening in some people improving at the expense of the distance vision
• blurry vision
• difficulty reading in dim light
• poor vision at night
• glare and halos around lights, and
• occasionally, double vision.

Cataract examination in London
The most important parts of your eye examination so far as cataracts are concerned is your level of vision with and without glasses and whether or not the vision can be improved with a new glasses prescription.

If I cannot improve your vision to the driving standard, then you’ll require cataract surgery if you wish to continue to drive. Even if the patient does not drive cataract surgery is still advisable because the driving test represents a threshold beyond which the cataract becomes advanced. As your cataract advances, the rate of visual deterioration increases and the risks of surgery also increases.

Other essential parts of the cataract examination

1. An eye health assessment to ensure that cataract is the only eye condition present and that there are no other causes for poor vision. This is crucial in determining which lens implant to use and to manage your expectations.
2. Biometry. Biometry is a particular test which we use to work out which lens implant to use in each patient’s eyes. Every patient needs a different strength or power of lens implant.
3. Corneal topography to measure astigmatism. Correction of astigmatism during cataract surgery is essential to ensure good surgical outcomes. If you have significant astigmatism, then you’ll need a toric lens implant to give proper vision following surgery.

The final parts of the cataract examination relate to counselling you about:

Whether or not you will need glasses after surgery. I will determine this by the type of lens implant I recommend. Standard monofocal lens implants can correct the distance vision in patients who do not have astigmatism, but all of these patients will need reading glasses.

Patients with astigmatism will need glasses for both the distance and for reading if I don’t implant a toric lens. A toric monofocal lens will correct the distance vision if you have astigmatism, but you will still need reading glasses.

Finally, multifocal lens implants will enable you to see at all ranges without the need to wear glasses. If you have astigmatism and want to be completely glasses-free, then a toric multifocal lens implant will correct every aspect of your vision.

When do I recommend cataract surgery?
Mild cloudiness of the eye’s natural lens is a normal part of ageing. When cloudiness becomes sufficient to affect the vision or cause symptoms, I make the diagnosis of cataracts. Cataracts usually get slowly worse over time and the only treatment to permanently solve the problem and restore full vision is to remove them. The procedure is called cataract surgery.

Surgery isn’t necessary if your vision isn’t significantly affected and you don’t have difficulties carrying out everyday tasks. However many patients find the presence of a cataract worrying and find coping with the uncertainty of what will happen to their vision difficult.

In the past, there was a time when, for technical reasons, we would wait for a cataract to be ‘ripen’ or become ready for removal. That is most certainly not the case any more.

With modern cataract surgery, eye surgeons can remove a cataract at any stage. The advances in technology and particularly safety means that modern cataract surgery is a minimal risk procedure. We can even perform lens exchange procedures on patients before they develop a cataract to correct their vision and free them from needing glasses.

The cataract operation
Cataract surgery is a relatively straightforward procedure that usually takes 15 to 20 minutes. We usually carry it out as day surgery under local anaesthetic with some mild sedation, which means you’ll be awake during the procedure and can go home on the same day.

The cataract operation itself is a keyhole surgery, and I performed through 2 or 3 tiny incisions (no longer than 3mm) in the white of the eye. I then fragment the natural lens and remove it through the keyhole incision. After I remove the natural lens, I implant a folded-up, small plastic lens called an intraocular implant or intraocular lens through the keyhole incision. The plastic lens unfolds inside your eye after I place it in the correct position.

If you have cataracts in both eyes, I will discuss the option of operating on both eyes at the same time. If you have mild cataracts, then this is possible, and the vision typically takes 24 to 48 hours to clear, so surgery on both eyes on the same day is perfectly acceptable. If, however, you have medium to advanced cataracts I will typically operate on each eye a few weeks apart because your vision can take 3 to 7 days to clear following surgery. This gives the first eye time to heal and time for your vision to return to normal before having surgery in your second eye.

The risks of cataract surgery
When considering the risks of cataract surgery, it is essential you understand that not having surgery also has risks. The cataract will progress over time and when fully mature cataracts can result in total loss of vision.

The risk of permanent loss of vision in one eye after cataract surgery is 1 in 10,000 operations. The chance of this happening in both eyes is 1 in 12 million procedures. The most common cause of vision reduction after cataract surgery is an infection, but other rare reasons include retinal problems such as retinal detachment and bleeding under the retina

The risk of having reduced vision and needing a second operation to correct any problem is 1 in 500. The risk of having a minor issue that requires further treatment with eye drops is 1 in 100.