Lens replacement surgery, also known as refractive lens exchange (RLE), is similar to cataract surgery in that it removes your eye's natural lens and replaces it with an acrylic artificial lens to improve your vision. However, unlike in cataract surgery, where the lens removed is cloudy, in lens replacement surgery, the lens removed is clear but faulty as it doesn’t allow you to focus clearly at all distances.
Lens replacement surgery is, therefore, designed to remove your need to wear glasses and contact lenses, and can also correct astigmatism. The artificial lenses are multifocal, which means after they are implanted into both of your eyes, you will be able to focus clearly at all distances (near, intermediate and far).
This procedure is only offered to those aged above 40 years who need to wear prescription glasses and meet strict suitability criteria. This includes the absence of any eye diseases or conditions, except short-sightedness (myopia), long-sightedness (hypermetropia) or presbyopia (age-related decline in your near vision).
Lens replacement surgery is performed in the same way as cataract surgery. You will be given two different types of eye drops — eye drops to numb your eye and eye drops to widen your pupils so your surgeon can get a better view of your lens. You will be awake during your surgery but will not feel any pain and can be given a sedative to help relax you.
A very small cut will be made into your eye, and your natural, clear lens will be broken up using an ultrasonic probe. The fragments will be removed via a fine tube. Finally, your artificial lens will be inserted. No stitches are usually needed.
The surgery takes around 25–30 minutes and is performed as a day case procedure. This means you can return home on the same day as your surgery. Each of your eyes will be operated on separately, usually one to two weeks apart. Your brain will adjust to the images coming from your new lens more efficiently if your second eye is operated on as soon as your first eye has recovered from the surgery.
There are several different types of artificial lenses that can be implanted, depending on your particular needs, such as multifocal lenses to help you see clearly at all distances and toric multifocal lenses, which correct for astigmatism too.
More recently, there are also extended depth of focus implants (EDOF), which are designed differently from traditional multifocal lenses. They offer enhanced depth of focus and reduced visual disturbances, such as glare, halos and starbursts, which can occur with traditional multifocal lenses.
Your surgeon will discuss your visual needs with you, so you can make an informed decision about which type of artificial lenses you want.
Immediately after your surgery, you will need someone to escort you home as your eye will be covered with a protective pad and shield, which will impair your vision.
You will need to wear your protective pad and shield continuously for the first 24 hours and after that wear it at night for one week, following the advice of your surgeon. This is to prevent you from rubbing or pushing your eye when you're sleeping, which can irritate or damage the site where the cut was made.
You may experience blurry vision for the first few days after your surgery, which will gradually clear up. Your vision should stabilise in around two to four weeks. You will need to take the eye drops prescribed by your surgeon for around four weeks to help prevent infection and aid healing.
You should avoid exercise, swimming and using computers for at least the first two weeks following your surgery. You can return to driving once you meet the minimum DVLA requirements ie you can read a licence plate number from 20 metres away.
Rare complications of lens replacement surgery include infection, inflammation of your cornea, inflammation of your retina, increased eye pressure, retinal detachment, which is more common if you are shortsighted, swelling of your cornea, and rupture of the back of the capsule which holds your lens. In cases of rupture, you will need surgery and may need a new lens implanted.
During the recovery process, around one in 20 patients with traditional multifocal lens implants develop visual disturbances at night ie glare, halos and starbursts. In most cases, these disturbances disappear after six to 12 months as your brain adapts to the new lenses.
It is common to have dry eyes after surgery, however, in a minority of cases dry eyes persist. This can be treated daily with lubricating eye drops.
In one in five cases, your lens capsule, which holds your lens, thickens and becomes cloudy after surgery. This will blur your vision and needs treatment with further surgery, specifically a YAG laser capsulotomy.
The more common risks of lens replacement surgery may be an acceptable trade-off if you are aged over 40 and have a high glasses prescription, a strong desire to be less dependent on your glasses or contact lenses, and are not suitable for laser vision correction.
Your surgeon will discuss the risks and benefits of lens replacement surgery with you, so you can make the best decision for your particular circumstances.
Around 95% of patients no longer need to wear glasses or contact lenses, with only around 5% needing to wear glasses or contact lenses occasionally for specific activities.
Research continues to improve lens replacement surgery and the artificial lenses implanted. Recently, a new type of artificial lens has been developed, light adjustable lenses, which are made of light-sensitive silicone. These lenses will allow your surgeon to adjust your lens power after surgery to tailor it to your specific needs. This will hopefully further increase the number of patients who can enjoy complete freedom from glasses and contact lenses.
Mr Jagmohan Chawla is a Consultant Ophthalmic Surgeon at Spire Hartswood Hospital, specialising in cataract surgery, lens replacement surgery, YAG and Argon laser eye treatments, glaucoma management and oculoplastic procedures, such as blepharoplasty, He also has special interests in refractive phacoemulsification.
If you're concerned about symptoms you're experiencing or require further information on the subject, talk to a GP or see an expert consultant at your local Spire hospital.