Refractive lens exchange surgery at Spire Dunedin Hospital

Refractive lens surgery, (also called clear lens exchange or lens exchange) is very similar to cataract removal surgery – one of the most commonly performed procedures in the UK according to clinical data. It removes the natural crystalline lens in the eye with a clear artificial intraocular lens (IOL) and can help improve your eyesight, often eliminating the need to wear glasses or contact lenses

What is refractive lens replacement?

Recent advances in the safety and predictability of micro-incision cataract surgery mean that we are now able to offer this surgery to patients who have minimal or no cataract symptoms but would like to reduce their need for spectacles.

During this procedure the natural lens of the eye is replaced with an artificial intraocular lens, the power of which can be adjusted on an individual basis to dramatically reduce spectacle dependence.

Surgery is particularly effective in those over 50 years who already wear glasses/contact lenses, to correct distance vision, and now find they need to use reading glasses as well. Glasses and contact lens use can obviously be highly inconvenient and does not always have the effect of producing a clear image. Refractive lens exchange offers the option of improved visual quality without the need for glasses or contact lenses.

What is involved in refractive lens exchange?

New techniques allow incision size to be decreased to less than 2mm. These small incisions seal themselves immediately after surgery, without stitches, and normal daily activities can be resumed soon after surgery. A further advantage of no-stitch incisions is that they do not cause a secondary focusing problem known as astigmatism.

After the incision has been made a round opening is created in the lens capsule. A phacoemulsification probe is then inserted, breaking the lens into tiny pieces which are sucked out of the eye. Phacoemulsification uses high-speed ultrasound waves, vibrating 40,000 times per second. Ultrasound phacoemulsification is quicker and safer than laser to remove the natural lens.

A lens implant is then placed in the lens capsule to replace the natural lens and return focusing function to the eye. The latest preoperative measuring and surgical techniques allow 90-95% of people to be independent of distance spectacles directly following refractive lens exchange. It is also possible to insert multifocal lenses helping to correct for the need for reading spectacles.

Our consultant will be able to advise you on the latest developments in intraocular lens technology and which models are most appropriate, on an individual basis.

How long will surgery take?

Lens surgery is a painless experience and the vast majority of operations are now done as a day case procedure. Two kinds of anaesthesia are used - topical anaaesthesia and regional anaesthesia.

Topical anaesthesia is very popular with many people because no needles are required. Instead, painless drops are used to numb the eye. No eye patch is needed and patients usually notice improved vision after 24 hours. This technique can result in a quicker recovery with fewer side effects and is completely pain free. The eye is fully anaesthetised but otherwise you are awake during the procedure, which takes about 15 minutes. 

The alternative procedure involves a Sub-Tenon’s anaesthesia where a local anaesthetic is injected into the tissues around the eye. The eye is patched for the rest of the day and patients usually notice improved vision after 24-48 hours.

Local anaesthesia also avoids the post-operative hangover from a general anaesthetic in patients with, for example, chest problems.

The operation is usually performed as a day case, shortening the time in hospital and reducing expense for the patient.

General anaesthesia is still available for patients who prefer to be completely asleep. Many patients worry that they will see what is happening during the operation but all that is usually noticed is a bright light and vague shapes. Although you have to lie fairly still, there is no need to be rigidly immobile - being alert means a patient can adjust their position or even cough or sneeze, provided some warning is given.

Risks and complications of refractive lens surgery?

Many advances in recent years have made the operation safer and improved the visual performance of the new lens. However, you should be aware that there is a small risk of complications, either during or after the operation. Complications are usually treatable, possibly requiring further surgery. In a few cases serious problems such as infection or retinal detachment occur, which may result in visual loss. A continuous audit programme is run to reduce these risks and results are consistently better than national benchmark data.

One of the commonest problems following lens surgery is the development of posterior capsule opacification, as a reaction to the presence of the lens implant. This can result in blurred vision but is easily treated as an outpatient procedure using a YAG laser.

Benefits of refractive lens surgery include:

• Greater clarity of vision - vision is crisper and sharper;
• Many studies have shown that people enjoy improved quality of life after successful lens replacement surgery. Most people feel that driving and activities such as reading, sewing, golf and using a computer are all much easier.
• Removal of astigmatism through the use of Toric lenses which allow the power of the lens to be different at different orientations within the eye. This allows correction of abnormal corneal curvature and increases independence from spectacles post-operatively.
• No subsequent need for reading glasses, for close distance visual focusing, in selected cases. Many people are delighted with this option but it does have some drawbacks, including possible haloes around lights at night. Our consultants here at Spire Dunedin will discuss the relative merits and whether or not a multifocal lens is appropriate for you, on an individual basis.

Note: Eye measurement and lens technology are continuously improving and the vast majority of patients find that they no longer require glasses or contact lenses for the majority of activities. However, it is impossible to guarantee that no glasses or contact lenses will be required after the procedure, but around 90-95% of patients achieve spectacle independence following surgery. If one of the gentle multifocal lenses are used then this usually enables around 90% of activities to be carried out without reading spectacles, with occasional use of glasses for smaller print and/or dim light situations.

Our consultants are very happy to discuss the procedure with you. Don't hesitate to contact our Ophthalmology department to find out more.