A guide to premium lens surgery
When the lenses of the eyes become dysfunctional, lens surgery is an option to replace the lenses with artificial ones. In this article, a consultant ophthalmic surgeon, Mr Sidath Wijeltillek,a explains the options for premium lens exchange surgery.
What are lenses?
The lenses are transparent discs of proteins (crystallins) that are located in the eye behind the cornea. The lenses are the final structure that light passes through before reaching the retina, where the light is converted into visual data. Their purpose is to focus vision and relay fine detail at various distances. They can become dysfunctional over time, due to the crystallins destabilising, cells not regenerating as rapidly as in youth, and cumulative exposure to sunlight. The lenses then can become cloudy and opaque, leading to cataracts, or they can become rigid and unable to calibrate to refocus, leading to nearsightedness (presbyopia).
Lenses can also be disordered for reasons besides ageing. Abnormally shaped or structured eyes– which can include eyes that are too long or short, lenses that are too thin or thick, and the curve of the eyeball being too steep or flat – can occur due to illness or can be present from birth.
Refractive errors and lens complications lead to blurry vision and difficulties seeing at various distances.
To correct lens issues, surgical replacement is a popular option for patients. The surgery is called intraocular lens (IOLs) exchange.
What is lens surgery?
The procedure involves the surgeon making a small incision on the surface of the eye, which will be numbed with anaesthetic eye drops (although some patients may be put under a general anaesthetic). Through the incision, the surgeon can extract or destroy the defective lens using an ultrasonic probe. A synthetic lens is then inserted. Typically, no stitches or sutures are needed to seal the incision. The procedure takes around 30 minutes to perform, and patients can go home the same day, provided they wear protective eyeglasses or shades to shield against unintentional eye touching and light sensitivity. The eyes should not make contact with water for at least two weeks to avoid infection or irritation.
At a basic level, the synthetic lenses used for IOL surgery are monofocal, meaning that they may be useful for distance sight but will not be useful for mid- or short-range distances – or vice versa, where they can help the patient see up close but do not provide clear vision in the distance. This can be a source of frustration for patients, but now there are more premium options for IOLs that patients can select from, according to their needs and lifestyles, to allow them to see in a way that suits them best.
What are the options for premium lenses?
Premium lenses reduce a patient’s reliance on glasses and contact lenses and can correct multiple refractive issues at once -- a patient with cataracts and astigmatism can have both seen to in the same surgery.
Toric lenses
Toric lenses can be used to correct astigmatism, which is related to the shape of the cornea and causes streaky lights in vision. A Toric lens can also help patients become less reliant on glasses for distance vision, though it is also single focus.
Multifocal lenses
Multifocal lenses can offer different focal points for near, mid, and far distances. The usual side effects that can come with multifocal lenses are reduced contrast sensitivity, which would be more prominent at night – almost all patients who receive this implant can expect some light distortion. This usually resolves after a few weeks.
Extended depth of focus lenses
Extended depth of focus (EDOF) lenses provide focus for distance and mid-distance in a continuous range and are associated with fewer side effects than multifocal lenses. These lenses are used to correct presbyopia. These lenses work by creating a single elongated focal point to extend the range of vision.
IOLs are designed to stay in the eyes and correct the vision permanently (barring any changes to the eye over time, which is a possibility, such as eye trauma, cancer, or degenerative eye diseases). The lenses are not susceptible to cataracts, but complications such as headaches, glaring lights, and eye discomfort are possible, however the risk is quite low, as this is a procedure with a high success rate.
