Refractive lens exchange like implantable contact lenses is capable of treating very high degrees of hypermetropia and myopia and are often considered when your prescription falls beyond the treatable range of either Lasik or Lasek. If your prescription is higher than -10.00 (short-sighted) or +5.00 (long-sighted) then refractive lens exchange is likely to be suggested to you by your surgeon.
Unlike implantable contact lenses, refractive lens exchange is generally considered for people over the age of 45 years old who already have problems with their near vision. Such people will be most likely wearing varifocals, bifocals, separate distance and reading glasses or be wearing multifocal contact lenses.
About Refractive Lens Exchange:
Put simply, the refractive lens exchange procedure involves removing your eye’s natural lens and replacing it with an artificial lens (lens implant) whose power is calculated to eliminate the prescription in your glasses or contact lenses. The natural lens inside your eye sits inside a lens capsule (like a bag) and when it is removed this capsule is left intact. The new artificial lens is then placed back into this capsule in the exact same position as your natural lens was located before it was removed.
Who is Refractive Lens Exchange Suitable For?
Refractive lens exchange is generally recommended for people over 45 years old and this is because at this age people will have already started to develop presbyopia. Presbyopia describes the natural ageing process of the lens within your eye which results in reduced ability to focus things close to you e.g. reading. Consequently, when the natural lens in your eye is removed during refractive lens exchange you will no longer have the ability to focus on things close to you. If you already need spectacles for near vision as a result of your age, then this is much less likely to have an impact on you.
Refractive lens exchange can be carried out on people below the age of 45 but it is important to understand that having surgery at this age will mean that your near vision will be worse following surgery. However, this may be a small price to pay for those people with very high prescriptions if it means they no longer have to wear their incredibly thick glasses for walking around in. Over the past few years however refractive lens exchange has advanced considerably allowing both your reading vision and distance vision to be corrected. The ways in which refractive lens exchange can treat both distance and near vision is as follows:
How Can Refractive Lens exchange Treat Both Distance & Near Vision?
- Monovision: Monovision refers to the refractive lens exchange procedure whereby one of your eyes (dominant eye) is corrected for distance vision and the other eye (non-dominant eye) is corrected for near vision. This means that one of the lens implants that are placed in your eye focuses on distance vision and the other focuses for near vision.
- Accommodating lens: During standard refractive lens exchange, the natural lens in your eye will be replaced with a single vision distance lens to eliminate your prescription. If this is done to both eyes the aim is to leave you with perfect distance vision but you will still require glasses for close vision tasks. If an accommodating lens (e.g. tetra flex) is used instead, then you will still retain some near vision. The lens implant is placed in the lens capsule where your natural lens was removed from and it works in tandem with the existing muscles in your eyes. As the focusing muscles in your eye contract to look at something up close so the accommodating lens moves forward (as it would with your natural lens) which results in clear near vision. The lens moves backwards and forwards as you change from distance to near vision and vice versa. It is important to realise that refractive lens exchange using an accommodating lens will not result in perfect near vision but is likely to be adequate for reading for short periods of time and for tasks such as checking your phone, reading a menu etc. Prolonged reading and especially when the print is small will most likely still require reading glasses.
- Multifocal refractive lens exchange: This is an alternative to an accommodating lens and is similar in design to a multifocal contact lens or varifocal in that there are different power zones on the lens for different visual requirements. E.g. there are zones on the lens for distance, intermediate and near vision. Such a lens relies on your brain to select the appropriate zone for a particular distance and therefore it is important that people considering such a lens have had a successful trial of multifocal contact lenses. Generally speaking multifocal refractive lens exchange results in better near vision than the accommodating lenses but the distance vision is often not as good. In addition to this, multifocal lenses are generally associated with more visual aberrations such as glare and haloes. It is because of this, that surgeons often combine a multifocal lens (non-dominant eye) with an accommodating lens (dominant eye) to get the best out of both lenses.
How Much Does Refractive Lens Exchange Cost?
The cost of refractive lens exchange will vary based on the clinic you choose and your exact prescription requirements. Price for the surgery typically starts from about £1500 per eye but this could be as much as £3500 per eye depending on what type of lens implant you require. Single vision lens implants are the least expensive but you will pay more for a toric lens implant and a multifocal lens implant.
Toric lens implants are required if you have a significant amount of astigmatism. A standard implant can be used if your astigmatism is only mild. You will only know for certain if you need a toric lens after you have been for a consultation.
Multifocal lens implants are also more expensive and the reason for this is that they allow you to see for both distance and reading vision following your surgery. If you choose to have single vision lens implants you are likely to need glasses for reading after surgery.
As you can see there are various factors that affect the price of refractive lens exchange and the only real way to get an accurate price is by going for a consultation at your preferred clinic.
Final Points on Refractive Lens Exchange:
As surgeons become increasingly confident with refractive lens exchange and the lenses available become more and more sophisticated so they try new ways of combining lenses. Some surgeons are starting to combine different types of multifocal contact lenses so as to get the best overall results. For example, one multifocal lens may have a bias towards distance vision and the other towards near vision and so combining them may produce optimal visual performance. Exactly which refractive lens exchange combination is best for you should be left to the expertise of the surgeon. Your surgeon will weigh up your prescription, lifestyle and visual requirements and come up with the best solution for you.
As yet refractive lens exchange is still considered a little bit of a compromise as you are unlikely to get perfect distance, intermediate and near vision. However, if you go into the surgery with realistic expectations and your surgeon has fully explained everything to you, then it is likely to be a life-changing surgery.