24 July 2021
If you find focusing on objects ‘close up’ difficult and wearing glasses unsuitable or inconvenient then help is at hand. Debbie Thorpe of Spire Norwich Hospital asks Consultant Ophthalmologist Mr David Spokes what’s available for patients in Norfolk?
How many times have you found yourself stretching your arm out to full length to read the cooking instructions on food packaging? Or witnessed someone else doing it? I know I do it!
As we grow older, the lens of our eyes becomes less flexible, leading to problems with near vision. Tasks accomplished without glasses for a younger person are now more difficult. Reading, using a computer and other types of close work are a burden. This problem can be particularly troublesome in people who need to wear glasses for both near and distance – needing different types of glasses throughout the day, or varifocals, which not everyone finds suitable or convenient.
Mr David Spokes, Consultant Ophthalmologist at Spire Norwich Hospital explains “Over the last few years there has been a large increase in demand for lens exchange surgery, in which the eye’s ageing lens is replaced by an implant lens that is able to focus for both distance and near.
How is the procedure performed?
“Prior to surgery patients are given two sets of eye drops – the first will dilate or widen the pupils, making it easier to see the lens. The second will provide a local anaesthetic to the eye. Patients may be aware of light and movement while being treated, but will not feel any pain.
Once the anaesthetic has taken effect, a tiny incision is made on the cornea and an ultrasound probe is used to break up the lens. The fragments are removed with a fine tube and a new lens is inserted. The whole procedure only takes around 20-30 minutes. Most patients can resume most of their normal activities the next day, and enjoy the immediate benefit of improved vision.”
What about aftercare – do patients have to be careful following this procedure?
Mr Spokes continues “Usually patients are able to go home on the same day as their treatment, however they will need someone to accompany them while their vision recovers. The eyes are covered with a protective shield for a few days following the procedure. I advise to keep the shield on at night for a week or two to prevent rubbing the eye while sleeping.”
What type of lens is used?
“There are two main types of lens implant available to achieve good vision over a range of distances:
- Multifocal Lens (MFIOL) and
- Extended Depth of Focus lens (EDoF)
The MFIOL has been refined so that vision is good with few optical irregularities such as glare and haloes. The EDoF lens gives clearer vision for distance and intermediate with less glare and haloes, but patients may still need glasses for very small print. When choosing which types of lens, caution is recommended for those who are dependent on night driving in case there is some glare. Your surgeon will help you make the right choice of lens for you.”
Can lens implant treatment cause cataracts?
“With the multifocal lens there is no concern about the development of cataract in the future, because it is the ageing natural lens that forms a cataract, and this has been replaced by the new lens implant. The multifocal and EDoF lenses are also a very good choice for use during cataract surgery.
Cataract surgery gives the opportunity to correct vision for both distance and near if a multifocal or EDoF lens is used.”
What visual problems can be treated with a multifocal / EDoF lens?
- Short sight (myopia) – vision is better for near than distance
- Long sight (hyperopia) – glasses are needed for distance and near
- Astigmatism – the eye is not perfectly round so light is focussed at more than one point inside the eye causing a blurry or distorted image. Often correctable with a toric lens implant
- Presbyopia – a progressive difficulty with near vision that occurs in everyone after the age of about 45, so it becomes harder to read without glasses
- Cataract – clouding of the eye’s natural lens resulting in blurred vision, which cannot be fully corrected with glasses
Mr Spokes concludes “The type of person who will benefit most from multifocal or EDoF lens surgery is someone over the age of 50 who is having trouble with their eyesight, or someone who is developing problems due to cataract formation.
The most important factors for a successful result in multifocal or EDoF lens implantation are accurate measurement of the eye prior to the procedure and a surgeon who is highly experienced in lens replacement surgery.”
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