During cataract surgeries, the natural lenses of the patients are removed and artificial lenses are placed in the eye.
Tri-focus lenses, which have been used for a while, are called "smart lens" among the public. The popularity of these lenses, whose real name is "Trifocal Lens", is gradually increasing. Representing Turkish ophthalmologists, Turkish Ophthalmology Association President Prof. Dr. İzzet Can drew attention to the fact that these lenses are quite advanced but not smart in the way they are thought. Saying that the main goal is to get rid of glasses, Can clarified various questions about smart lenses.
What is a smart lens?
The real name of the lenses referred to as smart are "trifocal lenses", that is, trifocal lenses. These lenses are attached to the eye with cataract surgery and allow the patient to see the near (35-45 cm), intermediate (60-80 cm) and far (5 meters and beyond) distances of the eye without the need for glasses. In summary, they aim to make the person independent from the glasses.
Which eye defects are treated with smart lenses?
Trifocal lenses correct three basic conditions: 1) Cataract; 2) Presbyopia, ie being unable to see close relatives due to age; 3) Astigmatism when needed.
In fact, all intraocular lenses, whether single or multi-focused, provide the treatment of cataract disease that prevents light entering the eye and creating a healthy image. Cataract surgery serves to eliminate the problem by replacing our lens organ, which becomes dense and does not transmit light into the eye, with an artificial lens.
The artificial lens worn on the eye during surgery may have functions other than restoring transparency. In order to provide these functions, in addition to the far focus, if the near and intermediate distance focuses are added to the lens, not only distance vision but also near and intermediate distance vision without glasses is achieved.
Why are these lenses called smart?
In fact, there is no such name as "smart lens" in medical terminology. This naming is unfortunately introduced as a marketing method, but admittedly it has been extremely successful. In fact, the use of the word "smart" means that it adjusts itself to changing conditions, and adjusts itself to those conditions. However, these lenses worn inside the eye do not have the ability to adapt according to the distance, so their physical properties do not change according to the situation. They only split the light for three separate foci.
As the Turkish Ophthalmology Association (TOD), we have no objection to naming the smart lens on the condition that it is understood correctly by the public. The problem here is that among the commercialized medical services, this is being introduced to patients with incorrect information. For example, we saw that a patient who said 'I had smart lenses put on my eye' did not know that he had actually had cataract surgery and thought he had something that could be easily inserted and removed, such as a contact lens. Such examples should not be experienced and patients should be informed correctly.
Can lenses be applied to everyone?
This surgery should be performed after the age of 45, the age of presbyopia. The ideal age group can be said to be 55-70. However, these lenses can also be used at a young age in cases such as removal of the lens organ due to trauma or illness at a young age, or youth cataracts.
The preparation for the surgery to be done by planning the use of lenses is perhaps much more important than the surgery itself. These lenses may not be suitable for everyone. Life styles of the patients should be questioned by the doctor. Trifocal lenses create a slight loss of contrast. Therefore, the patient should not belong to a profession dealing with visual detail. Or it may not be suitable for someone who drives heavily at night. Because, after these operations, disturbing appearances in the form of prolongation of lights can occur in about one out of ten patients, and this problem can continue for months.
How many types of smart lens are there?
We can describe the lenses for providing glasses-free distance, intermediate and near vision in two basic subgroups. 1) Trifocal lenses; 2) Lenses that increase the depth of focus (EDOF). While the trifocal ones of these lenses are more visually successful but have more side effects, EDOF lenses have fewer side effects but may be inadequate especially in near vision.
How does the surgery and treatment process progress?
Pre-operative preparation and patient information process requires additional tests that take longer than a normal cataract surgery preparation. However, the surgery itself is no different from a traditional phacoemulsification surgery. After the operation, the treatment process with eye drops for 2-3 weeks is continued as in classical surgeries.
Are there any side effects of smart lenses?
First of all, cataract surgeries on a world scale are operations with 1,5 percent complications. The short duration of the operation generally causes the patients to perceive this surgery as an on-the-go, easy and insignificant operation. However, phacoemulsification surgery is a very difficult surgery that requires great efforts to learn and develop from the doctor's perspective and requires experience.
In addition to all these, there are also specific problems with trifocal lenses. The most important of these are the problems called dysphotopsy, which causes seeing rings around lights, glare or star-shaped light stretches. In addition, patients may need to wear glasses or undergo laser surgery for this extra defect due to the refractive error that remains from time to time after surgery.
As Turkish Ophthalmology Association, do you recommend the use of these lenses?
If the preoperative evaluations are made correctly, the correct lenses are selected according to the patient and a good surgery is performed, the use of these lenses is of course functional and safe treatment methods as they provide cataract and presbyopia treatment. There are technical and technological developments regarding these lenses, which are added every day, and it is not difficult to predict that all cataract surgeries will be performed with such multi-functional lenses in a not too long process.