2014 03 19
How do we stop depending on our glasses?
Source: The Lietuvos Rytas newspaper
I only have two eyes, but I need three pairs of glasses. I use one pair for reading, the second one for working with documents and on the computer, and the third one I need for driving. Sometimes I leave a pair of glasses behind, and then the problems start.
Ophthalmologists are quite used to hearing similar complaints from older people. Middle age brings eyesight changes and even those who could see very well before start wearing glasses.
Far-sighted and near-sighted people encounter even more problems.
Is it possible to live without wearing spectacles? Ophthalmic microsurgeons Paulius Rudalevičius and Aidas Kirtiklis claim that it really is. Surgery to replace the lens of the eye with an artificial intraocular lens may help patients to regain clear eyesight. More about this in our conversation with Dr. P. Rudalevičius below.
-What are the functions of the lens?
The lens is a component of the optical system of the eye. The system helps the light to be focused on the retina, the information is sent via the fibres of the optic nerve to the brain, where the images are formed.
The lens is unique in that it can change the refractive power of the optical system of the eye – it doesn’t just allow the light to pass through but focuses it as well. Thanks to the lens doing its job, i.e. changing the refractive power of the optical system, a person can see clearly when looking at different distances – distant, medium, or when reading.
-Why does the eyesight of older people change?
The aging lens becomes harder and less flexible. Just like joints and tendons. It is not an illness, but a normal physiological process which is called presbyopia by medical professionals.
People start noticing changes in their eyes from approximately 45 years when they experience discomfort looking at near objects. In the beginning, the person tries to move the objects further away, but later they realize that they can’t read the small script at all. Men begin having difficulties when shaving and women when applying make-up, as they cannot see their face clearly up close.
People start wearing glasses for work. Every three to four years a new pair with stronger lenses are needed, as with the advancement of physiological processes the lens of the eye becomes harder and harder.
Far-sighted people are especially affected by this inconvenience. If earlier their difficulties were linked to near objects, presbyopia now makes it also hard for them to see things in the distance. People find themselves owning two or sometimes even three pairs of glasses: for reading, for driving, and for seeing clearly at mid-distance.
People become fully dependent on their glasses, and they have to have all pairs on them all the time if they want to be able to see clearly.
Spectacles with progressive lenses are an option, as they are intended for close-up work as well as distance viewing. However, some people find it hard to get used to or even tolerate them. Besides, these expensive lenses have to be replaced every few years as physiological processes continue.
There are many far-sighted people who are affected by the onset of presbyopia, and they make up about 35% of the total population.
Near-sighted people also experience presbyopia related problems. They continue having trouble seeing things in the distance but their glasses start standing in the way when they wish to read a book or a newspaper. They clearly see the text with their spectacles off but can’t see the faraway objects having looked up from their book.
The issue does not occur overnight, but it gradually makes our lives difficult.
-What is offered by modern ophthalmology?
Eye lenses can be replaced. We have been carrying out implantations of multifocal intraocular lenses for over five years now, and our experience shows that 90% of our patients are no longer dependent on their glasses, notwithstanding their age or severity of eyesight problems before the surgery. One-tenth of patients still put their glasses on for specific tasks.
We are delighted to hear that someone has become independent of their glasses, that they can read a receipt or product description in the shops, do a job requiring good near vision, or simply read a book.
Following the surgery, a number of patients are now actively pursuing sports. One patient is a photographer who can see without his glasses even in the specific light or in the presence of shadows. There are also a few surgeons who perform surgeries using a microscope. All this shows that the implanted intraocular lenses work really well.
We have also had some hunters who are pleased with their everyday vision and also see well during night-time hunting which requires dynamic vision and looking through optical devices.
-Does vision stay the same following implantation of intraocular lenses?
The qualities of the implanted lens do not change, and the surgery results are long-lasting, therefore the visual sensations of patients are the same all the time.
Nonetheless, we have to remember that it is not just the optical system of the eye, which is fixed through implantation of the artificial lens, that is responsible for the vision. The visual function can be impacted by a lot of different factors, e.g. trauma of the eye, retinal diseases, glaucoma, and stroke, which affects parts of the brain involved with vision.
-Are these lenses suitable for everyone?
The lenses are not suitable for patients with various eye diseases, trauma, or damage to the eye.
We would not approve of this surgery for a young near-sighted person, wearing -2 prescription spectacles, when he or she still has about twenty years before the possible onset of presbyopia. If a person wants to see without glasses, we could offer them a different solution.
We are not inclined to operate on patients with presbyopia who have unrealistic expectations and think that their eyes will see the same as they did when they were young. Accordingly, we talk and explain things in great detail to try to establish whether the person has certain expectations that we will not be able to fulfill.
Patients need to get used to the implanted lenses, just like getting used to the glasses, and on that account, some patience is required. It may take a few weeks or even months for the human brain to adjust to the artificial lenses.
Patients must understand what they are committing themselves to, and especially because they are getting the lenses for life.
There is another patient group that could benefit from intraocular lenses. These are presbyopia sufferers also affected by cataract - the condition in which the lens of the eye becomes progressively opaque. This cannot be helped by glasses, and the sufferers feel as if they are looking at the world through a dirty glass window. In such cases, the lens is replaced with an artificial one.
Cataract patients are normally implanted with a standard monofocal intraocular lens with one focusing distance, i.e. patients get the best possible clarity at one distance. For being able to see at different distances, patients need to wear glasses.
With the implantation of the multifocal lens, all problems are solved at once – the cataract is removed and the vision at all distances is improved.
-Can the body reject the implanted lens?
They are made of a material that is very well tolerated by the human body. I have never come across a lens rejection myself.
-What are the qualities of advanced intraocular lenses?
The lenses that we implant today have qualities that were not available 15-20 years ago. They have UV blocking protective filters. In addition, the latest lenses are able to adjust to different lighting conditions and improve vision at twilight.
The intraocular lenses that we currently use not only restore good vision at different distances but also correct corneal astigmatism, which means that patients do not require cylinders to be added to the lenses of their spectacles.
-Are there any age limits?
People are very different. An 85-year old may look and feel younger than a 60-year old, e.g. he can drive, travel, and go diving. The condition of the human eye may also vary a great deal. Our discussion with the patient is not limited to surgery, we also talk about their future plans. If the person wishes to pursue an active lifestyle and needs to be able to see well, there are no age limits.