Presbyopic clear lens exchange is when someone with presbyopia chooses to replace his or her natural lens with an intra-ocular lens (IOL), usually a multifocal lens. This allows them to have an IOL that corrects a refractive error (nearsighted, farsighted, or astigmatism). The surgery is similar to cataract surgery. PRELEX is not reimbursed by all medical aids.
What to expect with blade-less lens exchange surgery
Your eye surgeon will numb your eye with local anesthetic drops.
eye surgeon will numb your eye with local anesthetic drops.
1. In laser cataract surgery, an advanced femto-second laser replaces the use of a blade for the 2-3 corneal incisions near the edge of the cornea and opening the bag of the lens. It also breaks up the lens with a cataract for easy removal. Use of a laser can improve the precision and accuracy, potentially reducing risks of surgery.
2. Using special instruments, your ophthalmologist will break up the eye’s natural lens with ultrasound and gently vacuum out the pieces through one of the incisions. The “capsular bag” that holds your natural lens in place stays intact.
3 & 4 Intra ocular lens (IOL) is folded and inserted through the incision. It is placed in the “capsular bag,” where it unfolds. An IOL will refract light properly again, giving you clear vision at certain distances.
The tiny incisions in your eye are “self-sealing,” and you will not need stitches.
It could take 6-8 weeks after surgery to be able to focus fully. Basically, your eye has to heal and relearn how to focus at various distances to see clearly.
What is the difference between multifocal intra-ocular lenses and multifocal glasses?
Implantable multifocal lenses have several rings or zones set at different powers. With this design, you are actually using both near and far vision at the same time. Your brain learns to automatically select the right focus for what you want to see.
Unlike implantable multifocal lens where your brain selects the correct focus, multifocal glasses have different zones from top to bottom. Far vision is at the top, intermediate vision in the middle and near vision at the bottom. This means that you actually look through different focusing powers in the lens to focus at different distances.
Multifocal IOL compromises
There are some compromises and differences in the quality of vision that need to be understood.
• It takes time to adapt to seeing through the new multi-focal lenses
• A Multi-focal IOL can reduce the dependency on glasses but some people it might result in generally less sharp vision, which may become worse in dim light
• Not all patients are completely free of spectacles. About 10% will still require glasses for either distance, intermediate or near vision or a combination of these
• Reading vision is usually very good but does depend on lighting. Reading may not be as good in dim light
• The reading distance is typically at a fairly fixed distance so you will need to get used to moving reading material to that position
• The selection of the correct power of the lens implant is based on very sophisticated equipment and computer formulas but it is not an exact science. Occasionally the focal length of the lens can settle too far in the distance or too close. Usually this is correctable by changing the focal length of the implant used for the second eye, “top-up” LASIK surgery or implanting a second “piggy-back” IOL
• Astigmatism (a difference in the curvature of the cornea in different meridians) can be corrected during surgery by using limbal relaxing incisions or Multi-focal lenses with a toric (astigmatic) “in-built” correction
• Vision typically is far better with the lens implants in both eyes rather than in just one. The improvement in vision after the second eye surgery can be dramatic
• Visual side-effects such as circles or halos around lights particularly at night are common. In the vast majority of cases these phenomena are regarded as insignificant. If you do a lot of night driving Mono-focal lenses may be a better choice for you
If you are tired of searching for your reading glasses presbyopia surgery might be a great option for you.