Light adjustable lenses (LAL’s) are a recent development in corrective vision surgery and represent a significant leap forward for intraocular lenses. Intraocular lenses have various uses and they are most commonly used for treating cataracts. A cataract is effectively a clouding of the lens within your eye. During cataract surgery the old cloudy lens is replaced by a new artificial intraocular lens.
Intraocular lenses are also used in corrective vision surgery and the name given to this procedure is refractive lens exchange. Most people have refractive lens exchange if their prescription is too high for laser eye surgery. Refractive lens exchange is effectively the same as having cataract surgery, only the lens inside your eye is not being replaced because you have a cataract; it is being replaced to eliminate the prescription in your glasses/contact lenses.
Why Are Light Adjustable Lenses Better?
During refractive lens exchange the aim of the surgery is to replace your own natural lens with an intraocular lens that eliminates the prescription in your glasses or contact lenses. Calculating the power required for the lens implant is called Biometry and whilst it is accurate it is rarely ever 100% perfect. This means you may be left with a small residual prescription which may need glasses or further laser eye surgery. There are many reasons that this may occur but the most likely cause is that the healing process within your eye is variable. The beauty of a light adjustable lens is that the power can be altered after the lens has been placed in your eye. In fact, it can be altered as many times as you want until you are happy that your vision is perfect.
How Are Light Adjustable Lenses Altered?
Once your eyes have healed after surgery, your vision will be assessed by your surgeon. In most instances your vision will be good enough and therefore no adjustments will be required. If however your vision is not as good as it could be, your surgeon can then make the necessary adjustments to optimise your vision. The light adjustable lens implant is different to a standard lens implants in that it is made up of macromers (special components), whose shape and size can be altered on application of a specific wavelength of ultraviolet light.
By changing the size and shape of the lens implant, your prescription can be fine-tuned. This is a digital adjustment which is carried out by a computer and can correct even the most subtle of visual aberrations similar to how Wavefront laser eye surgery works. It is also possible to adjust the lens to give you both distance and reading vision if you are over the age of 45 years old and have presbyopia. The lens can be adjusted to give you a laser blended vision type correction or alternatively a bifocal or varifocal correction similar to your glasses. The procedure to fine tune your prescription is painless and normally only takes around 2 minutes. Once you and your surgeon are 100% happy with the vision, the power of the lens is then locked in place giving you perfect vision for life.
What Are The Risks of Light Adjustable Lens Implants?
As with all surgical procedures there are risks involved and these will be discussed with you by your surgeon. The risks are however exactly the same as they are for cataract surgery or refractive lens exchange. You can read about the risks of refractive lens exchange at the following link: Risks of refractive lens exchange.
In summary, the main advantage of light adjustable lenses is the fact that the prescription can be fine-tuned after surgery giving you a much higher chance of being glasses free for life.
How Much Do Light Adjustable Lenses Cost?
The cost of light adjustable lenses does vary between clinics but the minimum you are likely to pay is around £4000 per eye. They are generally more expensive than standard refractive lens exchange implants owing to the fact that the vision can be adjusted after they have been fitted. They are a relatively new development and therefore the price of light adjustable lenses is likely to reduce as they become more commonly used.
Am I likely to be suitable for light adjustable lenses?
Most people are suitable for light adjustable lenses and the criteria is the same as that for refractive lens exchange. The surgery is typically performed on people over the age of 40 years old and providing your eyes are healthy you are likely to be suitable for the procedure. Light adjustable lenses can pretty much treat any prescription and you are unlikely to be unsuitable based on the extent of your visual correction. Light adjustable lenses can treat both long and sighted prescriptions equally well and this is one of the main advantages over laser eye surgery which can only treat relatively low levels of long sightedness (plus prescriptions).
In terms of contraindications to surgery, the most common reasons are similar to not being suitable for laser eye surgery and you can read about these here.