Refractive Lens Exchange
Refractive Lens Exchange (RLE) is designed to restore distance and reading vision in the over 50s, and is an alternative to LASIK Blended Vision
Refractive Lens Exchange
Premium multifocal intraocular lenses have revolutionised what can be offered for patients having lens replacement surgery.
Refractive lens exchange may be a better option than laser eye surgery, such as LASIK or PRK, for some patients, especially those already needing glasses for reading (presbyopia) or whom are significantly long-sighted (hyperopia). Refractive lens exchange (usually abbreviated to RLE) is also known as refractive lens surgery, lens replacement surgery or clear lens exchange.
RLE surgery replaces the clear natural lens inside the front part of your eye with an artificial intraocular lens (IOL). The technical procedure is very similar to cataract surgery, although in RLE no cataract is present and the natural lens being removed is still clear.
There are a wide variety of artificial lenses available which will correct your prescription (refractive error) for any short-sight, long-sight and/or astigmatism, and so improving your general vision for e.g. driving or television.
Improving close vision is the most common reason for performing refractive lens exchange
More advanced premium multifocal IOLs can now also reduce or eliminate your need for reading glasses, bifocals or varifocals, improving both distance and reading vision. Improving close vision is the most common reason for performing refractive lens exchange.
RLE and loss of reading vision
Everyone loses the ability to focus for reading, known as presbyopia, becoming apparent after the age of 40-45 for most people. Presbyopia is a normal part of ageing, where your eye’s natural lens loses its flexibility and your ability to focus for close vision declines. It can appear to come on quite quickly, over a few weeks or months. Lens replacement surgery is most often performed to correct this age-related loss of near vision.
Suitability for lens exchange surgery
Patients who are best suited for lens replacement surgery include:
- Moderate to high degrees of long-sight (hyperopia)
- Those age 50+ who use reading glasses (presbyopia)
- Those not suitable for LASIK or phakic IOL treatment
Lens replacement surgery is most commonly used for people with presbyopia (using reading glasses after the age of 40) or higher degrees of long-sightedness, and for whom laser eye surgery (LASIK, PRK or LASEK) or phakic IOL surgery are not options.
If you suffer from both needing reading glasses and moderate to severe hyperopia so that your distance vision is quite blurred, lens surgery may be your only option to attain clear vision and no or reduced minimal reliance on glasses after your operation.
Lens surgery may be an option for those not suitable for LASIK
LASIK Blended Vision is used more commonly at Focus for many patients in their 40s and 50s due to its demonstrated safety profile, combining better reading vision with also treating any short-sight, long-sight or astigmatism. One of our surgeons can advise if lens replacement surgery (RLE) or LASIK Blended Vision is right for you.
Lens Replacement Surgery
RLE and cataract surgery
The operation for lens exchange surgery is essentially identical to cataract removal. In cataract surgery, the natural lens inside the eye has become somewhat opaque and the lens is being removed to restore vision lost to this impediment to clear sight. In RLE, the lens is clear without the changes found in cataract, and is being replaced to reduce or eliminate the need for glasses, either for distance, reading, or both.
The operation for lens exchange surgery is essentially identical to cataract removal
RLE can be a treatment for early cataracts
Lens replacement surgery is often considered by patients who have the beginnings of cataracts and which when left will gradually worsen and require standard cataract surgery. If you have been diagnosed with early-stage cataracts, you could elect to proceed to have lens replacement surgery, without waiting for the lens changes to progress and cause visual loss.
Intraocular implants can provide significantly better vision, compared to being dependent on reading glasses, bifocals, varifocals or contact lenses. Lens surgery then removes the possibility of developing cataracts, as the natural lens has replaced with an advanced implant.
Choice of lens implants
In common with cataract surgery (when done privately), you will have three main choices for which implant (intraocular lens, IOL) you will want after the removal of your natural lens. This depends on an assessment of your eyes and vision, and your visual requirements after surgery.
- Standard Monofocal IOLs – to correct your distance vision only (including topic IOLs that also correct astigmatism)
- Monofocal IOLs with monovision – to correct distance and reading – one eye is focused for sharp distance vision and the other focused for reading, liberating you from the need for glasses for all or most tasks – a very established option and similar in its effects to LASIK Blended Vision
- Premium Multifocal IOLs – to correct vision at multiple ranges, i.e. far, intermediate (PC) and reading vision
You may also see references to accommodating IOLs, which have been designed to allow vision at multiple distances by moving small distances inside the eye under the action of your normal focusing muscle. There is little evidence that these work in the long-term and so they are not offered at Focus.
The choice of lenses is very individual and will be determined at consultation with your surgeon, where you can discuss together your visual needs after treatment.
The RLE Procedure
Lens replacement surgery usually takes between 10 and 15 minutes per eye and is performed as a day-case. Each eye can be done separately, usually about a week apart, or both eyes can be treated on the same day (as is commonly done in other European countries and now increasingly in the UK).
Anaesthetic drops are used during lens surgery to ensure the eye is numb, so usually you will not feel any discomfort or pain.
Most people describe immediate improvement in their vision after surgery, and normal recovery to your full schedule of activity usually takes between several days and up to one week. The ultimate outcome of refractive lens surgery can take up to 4-8 weeks, and you may be aware of some changes in your vision, such as some blur, and halos and glare at night. You might also feel some dryness of a foreign body feeling as your eyes heal.
You should expect to be able to return to work and resume driving within a few days, and your surgeon will advise you on this. The new lens lives inside your eye and you will not be able to feel it, nor is it visible to anyone talking to you. It can only be seen during an eye examination with a specialist.
The artificial IOL (intraocular lens) is designed to be a permanent replacement for your natural lens and is created to last the rest of your life. Once the natural lens is removed, so too is the tendency to lose focusing power with age. The lens power will remain constant for the decades to come and so there is very little chance of the new focusing ability decreasing over time.
Refractive Lens Exchange or LASIK for severe prescriptions?
LASIK remains the most popular option for correcting short-and long-sight, including astigmatism, and can treat more than 95% of all prescriptions. However, for extreme prescriptions and some cases where the corneal anatomy is not fully normal, replacing the natural lens (refractive lens exchange, lens replacement surgery) or adding a lens in addition to your natural one (phakic IOL, ICL) can be better options.
This is most commonly the case with high degrees of long-sight (hyperopia, farsight) where the results will be better than is possible with laser eye surgery. LASIK is best used for up to +3.00 to +4.00 dioptres of long-sight, while above this level intraocular lenses can give a better and more stable outcome.
High levels of myopia (short-sight) can be more problematic with lens exchange surgery due to the higher incidence of retinal detachment, a vision threatening complication. Fortunately, the laser combination used at Focus can treat most short-sighted prescriptions without the need to consider lens surgery.
Lens replacement surgery is more expensive than LASIK correction, but is the correct option in certain patients with high prescriptions.
Non-surgical and surgical options
Presbyopia has traditionally been addressed non-surgically, with either glasses or contact lenses:
- Reading glasses, bought over-the-counter if distance vision is good
- Bifocal or varifocal glasses to correct distance as well as reading vision
- Contact lenses with monovision – one contact lens corrects far vision, the other allows clear reading
- Bifocal contact lenses
Surgical treatments are now available to you, which can correct far vision (e.g. driving and television) as well as clear reading and even intermediate vision ranges such as a computer screen. The two main choices are:
- LASIK Blended Vision
- Lens replacement surgery
The choice of procedure will depend on your age, prescription and personal preferences.
LASIK Blended Vision
Laser eye surgery can help restore lost reading vision through an approach called Blended Vision, a procedure pioneered by our chief surgeon David Allamby in 2003. Blended Vision can be a very good option for those aged 45-65 and does not require a visit to the operating theatre. The whole procedure can be completed in the laser suite in around 10 minutes for both eyes.
Blended Vision can be a very good option for those aged 45-65 and does not require a visit to the operating theatre
Not everyone is suitable for Blended Vision, which can be determined at your consultation. You can learn more about Blended Vision here.
Refractive Lens Exchange (RLE)
Vision after lens replacement surgery
Your requirement for glasses or contacts after refractive lens exchange will depend on the choice of intraocular lens (IOL) inserted at the time of surgery – monofocal IOLs, with or without monovision, or premium multifocal lenses.
1. Monofocal IOLs
Standard monofocal IOLs have been used worldwide in cataract surgery and lens replacement surgery (without cataract), and are the standard lens used in NHS cataract operations. These lenses will provide excellent vision in the daytime and low light, and have a low risk of night vision problems e.g. halos and glares.
However, these lenses are made to provide good vision at a single focal range, and most commonly are set for clear distance vision. Reading glasses will still be needed for print and computer use.
2. Monofocal IOLs with monovision
2. If you want to eliminate or reduce your dependence on reading glasses, monofocal lenses can still provide for and near vision through an option known as monovision. In this case, one IOL is selected to give sharp distance vision, e.g. driving and television, while the other IOL is focused for close vision, often liberating you from the need for glasses for most tasks. This is a very well established option and similar in its effects to LASIK Blended Vision. Because standard lenses are used, the costs are lower than premium multifocal lens implants.
3. Premium multifocal lenses
The development of premium multifocal lenses has revolutionised what can be offered with lens replacement surgery. The IOLs allow you to see at multiple ranges and typically reduce or eliminate the need for glasses for intermediate or near work.
The choice of IOL will depend on your visual requirements and if you have a preference for where you want your clearest vision, e.g. computer range or finer close-up work. Each IOL has its own advantages and disadvantages and so the choice of lens is best made between yourself and your surgeon, who can advise on the most suitable option for you.
The choice of lens is made between yourself and your surgeon, who can advise on the most suitable option for you
Risks and Side Effects
Refractive lens exchange is performed essentially the same way as cataract surgery, and therefore RLE complications are similar to cataract surgery complications.
Refractive lens exchange typically is reserved for people who are both farsighted and presbyopic (reading glasses-dependent). Lens replacement surgery is more invasive than laser-based refractive surgery such as LASIK and PRK and comes with slightly more risk.
However, sight-threatening complications are rare, and most complications can be treated successfully with medication or additional surgery. While refractive lens exchange has been proven safe and effective, all surgery has some degree of risk, which you should discuss in detail with your eye surgeon. Refractive lens exchange risks and complications include:
- Retinal detachment, especially in extremely nearsighted people
- Dislocated IOL
- Increased eye pressure (ocular hypertension)
- Infection or bleeding inside the eye
- Droopy eyelid (ptosis)
- Glare, halos and blurry vision from multifocal IOLs
Refractive lens exchange is more invasive surgery with a higher risk of complications, compared with other vision correction procedures. But the higher risks may be an acceptable trade-off if you have a severe refractive error and a strong desire to be less dependent on eyeglasses, contact lenses and/or reading glasses.