In this informative article, highly experienced consultant ophthalmic and oculoplastic surgeon Mr Jagmohan Chawla, shares his expert insight on refractive lens exchange, also known as lens replacement surgery, including how it is performed and how it compares to laser vision correction. Mr Chawla, who specialises in spectacle-free cataract surgery and refractive lens exchange, also details the associated risks and complications patients should be aware of, although the vast majority of procedures are very successful.
What is lens replacement surgery?
Lens replacement surgery or refractive lens exchange (RLE), also called clear lens extraction, may be a better option than laser vision correction for people with presbyopia and higher degrees of farsightedness and short-sightedness or pre-existing astigmatism.
Presbyopia is a naturally occurring age-related condition where the eye’s natural lens becomes harder and loses its ability to change its shape, resulting in loss of ability to focus on near objects. Presbyopia affects just about everyone and becomes noticeable sometime after forty years of age in most cases.
Refractive lens exchange replaces your eye’s natural lens with an acrylic artificial intraocular multifocal lens (IOL) to correct your defective eyesight and restore near vision and achieve sharper focus, reducing your need for readers or varifocal spectacles.
Following surgery to both eyes, multifocal intraocular lens implants enable you to focus at all distances including intermediate distances, e.g. working on computers, in due course. Using Toric customised multifocal lens implants, it is possible to eliminate pre-existing astigmatism and achieve a degree of spectacle freedom.
How is lens replacement surgery performed?
The procedure for refractive lens exchange is exactly similar to cataract surgery, with a difference in that the lens being replaced is clear, rather than a cloudy lens which is replaced in cataract surgery.
Lens replacement surgery usually takes about twenty-five to thirty minutes and is performed as a day case procedure. Each eye is done separately, usually about one to two weeks apart. The brain adjusts to new imagery coming from the new lens much better if the second eye is done as soon as the first eye has started settling down. This is known as cortical neuro-adaptation.
The operation is usually done under local anaesthetic and mild intravenous sedation. It can take a couple of days for the sight to start clearing up and near and distance vision stabilises in two to four weeks. It takes around two weeks before one can resume normal daily activities including light exercise, swimming and working on computers. Driving is possible within three days if the procedure has already been performed on the other eye. One may notice vision disturbances such as blurry vision, halos, glare or a scratchy sensation during the healing process for the first few days or weeks.
The artificial intraocular lens is a permanent replacement for your natural lens and is designed to last the rest of your life. Also, there is minimal risk of regression (loss of corrective effect or deterioration of vision) over time.
What are the risks and possible side effects of lens replacement surgery?
Refractive lens exchange is performed essentially the same way as cataract surgery and therefore the associated complications are similar. It has been proven to be an extremely safe and effective procedure although, as with any operation, there is some degree of risk.
Lens replacement surgery is more invasive that 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.
Risks and complications of refractive lens exchange include:
- retinal detachment, especially in near-sighted people
- increased eye pressure
- swelling of cornea
- inflammation or cystoid macular oedema
- droopy eyelids, which may require surgery to achieve optimal vision if present prior to RLE surgery
- glare, halos and starbursts at night time, which tend to subside within six to twelve months following surgery
- posterior capsular opacification, usually seen several years following RLE surgery and can be corrected with a short procedure of YAG laser capsulotomy in clinic
The relative higher risks may be an acceptable trade-off if you have severe a refractive error and a strong desire to be less dependent on eye glasses, contact lenses and/or reading glasses, are unsuitable for laser vision correction or are over forty years of age.
How does refractive lens exchange compare to laser vision correction?
After forty years of age when presbyopia sets in, laser vision correction is not a viable option for the majority of patients as you still need glasses for near work. Monovision (one eye corrected for near vision and the other for distance) may be an option with laser vision correction but it is not suitable for everyone and has permanent side effects, like loss of stereopsis and asthenopia.
Following laser vision correction, as age advances, cataracts may develop which would need surgery. However, this is associated with unpredictable refractive outcomes and the need to wear glasses again. An added advantage of lens replacement surgery is that a cataract cannot form at a later stage.
Pre-operative assessment is thorough with rigid selection criteria and not everyone is suitable for lens replacement surgery using multifocal lens implants. Even if you have had prior cataract surgery done with ordinary multifocal lens implants, one may still be suitable for piggyback lens implantation with multifocal lens implants, so as to enable one to acquire reading ability without having to resort to glasses.
You can read more about what results to expect from refractive lens exchange or cataract surgery, including expert guidance on aftercare, in Mr Chawla’s other detailed article on the topic.
If you think refractive lens exchange surgery could be right for you and you wish to schedule a consultation with Mr Chawla, you can do so by visiting his Top Doctors profile.