Currently people’s vision is naturally decreasing after the age of 40 and this has nothing in common with eventual eye defects like nearsightedness, farsightedness, or astigmatism. What’s more, this often arises with people who were never diagnosed with any eye defect.
Presbyopia is related to the progressive stiffening of the lenses and weakening ability to accommodate the eye (accommodating muscles slowly weaken). These changes cannot be prevented- resulting from the natural usage of our organism. Even the healthy lifestyle cannot assure that this will not occur. It is important to add that certain diseases, like diabetes, or taking antihistamines or antidepressants can accelerate the growth of presbyopia.
Estimates state that by 2020, the number of people worldwide struggling with presbyopia will be about 1.3 billion. This problem is easy to diagnose and possible to correct. It is worth addressing with the help of a specialist.
“Arms are too short!”- or reading the newspaper with farsightedness
The first symptoms of presbyopia are not felt in anyway: the accommodation disorders are felt as a great discomfort. This first stage of the stiffening of the lens occurs abruptly, and then at a certain time, slows down and effects the patient less violently. Every two or three years, this loss of visual clarity digresses a quarter or half a diopter. We laugh then, that our arms are two short for reading- namely that we are not able to hold the text the proper distance from our eyes in order to see it clearly and we conclude that we are farsighted. But this really does not enter the equation as “normal” farsightedness or even that possibility. This is evolving presbyopia, which has the following symptoms:
- unable to read a text up close- the smaller the letters, the greater the problem (phone text, footnote in a book, menu in a restaurant, text on the computer screen),
- headache and tired eyes, when we look up close,
- problems with vision accommodation during the twilight hours,
- double vision (diplopia).
You should be aware that after the age of 35, our vision, regardless of previously diagnosed defects, begins to deteriorate. Presbyopia is usually diagnosed after the age of 40 and its greatest severity occurs when we are 40-55 years old. Around the age of 60 (though some believe between the ages of 65 and 70) the process discontinues.
We can easily check if we have been affected by the first stages of presbyopia. Let’s focus upon the reading of a text up close, and then quickly look at a distance- i.e. out the window, at a picture or the television. If it takes a few seconds for our eyesight to adjust to the distance (to the moment when we see a sharp image), we need to seek the help of an ophthalmologist.
Correction of presbyopia – glasses
Presbyopia responds well to corrective glasses, but with an active lifestyle it is worth seeking another solution.
These arise in two variations, i.e. standard eye glass frames or half-frames with the flattening at the top. Standard glasses frames are recommended for patients who spend much of their time concentrating on objects nearby, i.e. working on a computer, analyzing documents, and reading. If we look through glasses to read objects at a distance, they will be unclear.
Therefore, if we must occasionally cast out eye at a distance, the ideal solution is the half-frame classes – characterized by wearing them toward the end of the nose with small lenses. Reading glasses are not worn all day, and are only used when we need to read something, which we see at close range. These glasses will often be put on, taken off, and place in our pocket.
Two pairs, bi-focal lenses and progressive lenses
If symptoms of presbyopia arise with someone who has been diagnosed with nearsightedness, until recently they would need to use two pairs of glasses.- the first to correct their vision defect and the second for reading. Then arose the development of bifocals or glasses that had two strengths – in the larger segment (when looking forward) was the strength to see at a distance, and in the lower segment- the higher strength permitted reading.
Yet moving from one segment to the other is very unnatural for the eye and abrupt, and not every patient is able to adjust to wearing bifocals. So progressive contact lenses were developed.
Thanks to progressive lenses, the value of changing the strengths occurs more naturally and fluidly. The upper part of the lens aids in seeing objects at a distance, the lower strength progresses to allow sharp vision at a middle distance (from several yards to a foot).
The lowest field aids in reading and seeing up close. The lower field serves to read and seeing things closer than a foot and a half. With progressive glasses, the lenses may correct the vision defect.
Correction of presbyopia – contact lenses
In the correction of presbyopia, progressive or multifocal contact lenses are very effective. They are multifocal, which allows both seeing at a distance and up close. Progressive lenses appear the same as other contact lenses, yet are constructed in such a way, that they prompt clear vision regardless of the distance.
The outer part of the lenses allows clear vision of objects at a far distance, medium distance (so called progressive channel) are also corrected, and with usage of the lower sphere, we are able to read the newspaper, book or observe objects up close.
However, it is worth noting, that the time for adaptation to wearing progressive lenses may last awhile, and in the case of the person with differing eye defects (each eye has a different defect) adaptation is not only further complicated but sometimes even impossible, which leads to finding a method solution through trial and error.
The use of multifocal lenses is associated with the necessity of frequent adjustments by the head and neck to optimize the correct angle and view. This can be tiring and irritating, and in the case of a degenerative spinal curvature, we should completely avoid using such lenses.
Optical providers often have two types of offers of progressive lenses- standardized and individual. The latter are designed to measure based on a computer examination- the computer program compiles several parameters regarding the vision defect as well as the structure of the eye and face.
Monovision can be achieved in a variety of ways: contact lenses, ophthalmological laser treatment or an inner lens implant. It depends upon this, that the patient wears one contact lens or has an intraocular lens implant for close up, and uses the second contact for distance. Monovision can also be achieved via the path of laser correction of presbyopia.
In the ideal case, the result of monovision can be so positive to free the patient from needing glasses or possibly just reading glasses. A medium outcome would be the lessening of the eye defect, which is connected to the lessening of the number of diopters needed in the reading glasses.
As specialists emphasize, people who start wearing monovision contact lenses should not drive a car or participate in sports.
Laser vision correction for presbyopia
Depending upon this, if presbyopia is the only eye disfunction, or if it is accompanied by other eye defects, the patient has a choice from the following laser correction methods:
- if no further defect- FemtoLASIK/Monovision/PresbyMax lens replacement,
- farsightedness/nearsightedness +3 to -5/ FemtoLASIK/Monovision/PresbyMax,
- with presbyopia and other vision defects- lens replacement with implants of one- or multifocal firm FineVision (Physiol), Lisa Tri(Zeiss), Symphony (AMO), Precision Presbyopic (Ophthec) or Panoptix (Alcon).
LASIK (laser assisted in situ keratomileusis): two stage technique; corneal incision by scalpel (microkeratome), with the corneal surface being fashioned in such a way to cause the image to focus upon the retina.
FemtoLASIK (All-Laser-LASIK): thanks to the precision of the femtosecond laser, surgeons can make the corneal incision, creating a thin flap with the width of .1mm. Using the excimer laser, he can fashion the now open cornea before refolding the flap into place.
PresbyMax: in conjunction with FemtoLasik, it is an individual multifocal Schwind Amaris laser profile that enables the correction of presbyopia. This profile is based on the increasing of spherical aberrations, so that near vision is even more precise and the tolerance of diopter differences between the left and right eye as received and observed by our brain would be minimal.
KAMRA: (currently not used) the FemtoLASIK method is combined with the use of a thin Kamra disk (Kamra Corneal Inlays), which allow both distance and near vision without the use of glasses following the refractive surgical procedure. Kamra are implants designed for patients between the ages of 45 and 60. The implant works by correcting the focus of the light rays in the inner eye: it reduces the amount of light falling on the retina by the periphery of the pupil. In this way, it eliminates those rays, that the lens of the person with presbyopia is unable to focus properly. The implant is a thin, flexible disk with a diameter of 3.8 mm with a 1.6 mm hole in the center. The entire procedure’s completion lasts about 15 minutes.
Lens replacement, also known as refractive lens replacement, can be done using a variety of individually tailored lenses. In the treatment of presbyopia, the following are used:
- The latest generation of multifocal lenses (trifocal lenses, for near and distance vision and the intermediate area).
- SMonofocal lenses (also known as “strengthening lenses,” are often used in cataract surgery).
- Toric lenses (for astigmatism correction):
toric trifocal lenses (correct presbyopia and astigmatism).
- EDOF lenses (extended depth of focus) by increasing the positive spherical values, allow good vision from a distance and from an intermediate area (i.e. cells).
- Phakic lenses are implanted in addition to the natural lenses.
Treatment of presbyopia- step by step
Prior to the procedure – initial examination
At the beginning of the first visit, we will give a comprehensive anamnestic questionnaire. We will note at this time, not only previous illnesses, operations and medicines that the patient is taking, but also, we clarify what is particularly burdensome with presbyopia and what correction methods are available. We will give volumes of information related to options for correcting presbyopia.
Complete evaluation of the eye
Next, we meticulously examine the eyes. We establish the sharpness of the vision and the exact degree of presbyopia. We exam the retina and measure the inner pressure of the eye. This exam also serves to reveal any other possible disease of the eye. In the next step, we measure the eye and carry out the optical biometrics, using the most precise method for measuring the length of the axes and partial sections of the eye. We also note the curvature of the cornea- this is completely touchless with the help of a laser, which performs the measurement across the axes of the eye. This method is completely safe and helps exclude any possible measurement mistakes made via an ultrasound.
Examination of the corneas
For the purpose of optimal correction of presbyopia, an exact map of the cornea is made. With the aid of corneal tomography, we precisely measure the front and back walls and their thickness. This exam helps to define the complete anatomy of the cornea. On the basis of this “map” the strength of the eye is fixed, which plays a very important role during the corrective surgery.
We offer further painless examinations on the front wall of the cornea- an optimally coherent tomography of the anterior segment of the eye. The exam is touchless and is comparable to a sonogram, instead of soundwaves there is a light laser.
Examination of wavefront
Next is the Wavefront exam. A light beam is directed at the eye, particularly upon the retina. From this place through the lens and cornea travels the front wave light. By this method one can especially underscore where the laser is needed for optimal vision strength.
Important before beginning the exam
You should not wear soft contact lenses for a week, and hard contacts for three weeks prior to the examination.
During the examination, eye drops are given to dilate the pupils. This causes a greater sensitivity to light, and for this reason you should not drive a car or operate any machinery for two or three hours after the exam.
What is the next step?
After the initial examination will be the discussion whether optical laser surgery in the given situation will be the best solution. The patient is informed about the operation procedure, risks and side effects and further treatments.
Setting the time for the procedure
If the patient opts for correction of presbyopia, we will work together to establish the ideal timeline. You may wear you contact lenses up to two days before the operation.
Laser correction of presbyopia
With this modern method, the patient can give up wearing glasses, by using two different lasers. A small incision is made in the cornea by the most modern femtosecond laser. Next, the excimer laser is used. So that sharp vision can again be achieved both near and far, the laser will be used on the dominant eye to see far off, while the second eye will be corrected for nearsightedness between -.5 and -1.5 diopters. In order that spatial vision will be to the least degree limited, we take care, so that the differences between the eyes is less than 1.5 diopters. Of course, in individual cases is a wide range of vision needs from near and far.
Each person, whether an amateur golfer or professional driver, needs better vision for distance, and therefore are more apt to accept lesser defects (like wearing glasses for night driving). In turn the one who sits all day in front of a computer and likes to read in the evening, will want better vision for near objects. If the procedure is performed in the second phase of life, problems with three-dimensional vision may occur afterwards.
The prince of poets, John Wolfgang von Goethe, had congenital monovision, which is why some call this Goethe vision
Before performing the procedure, we simulate the exact type of vision with contact lenses. This takes place in the course of the initial examination. If the initial exam is not sufficient to establish the final tolerance, the test can continue with different contact lenses, also for several days. About 80% of the time, people deal well with this process, 20% less so- for this group we can find a different method to correct presbyopia.
It is important to give yourself time to really adjust to the new vision. This means that the apparatus of vision may need several days to adjust again and see normally- without presbyopia.
Correction by implants
Presbyopia may be treated with special lens implants. This method was previously called cataract surgery, because it was based on the removal of the eye lens because of presbyopia and the placement of the artificial lenses, which could not suffer from cataracts.
The procedure is performed as an outpatient procedure, following a comprehensive vision exam. After numbing the cornea with drops, a small incision is made on the edge of the cornea. This cut is so small, that no stitch is needed to close it. The natural lens is disintegrated and suctioned with the help of ultrasound equipment. The lens sac remains intact the whole time. Next, through a small incision is placed the artificial lens, which develops on its own and exactly matches the eye. This is all pain free for the patient. After the procedure concludes, the eye is covered by a band and the patient can leave the clinic with his companion.
Multifocal lenses are very useful for the correction of presbyopia. It consists of several rings with each having different focusing ability. In this way, there remains several focal points in the eye, which enables vision both near and far. A weakness of multifocal lenses is the impediment of night driving (around reflectors and other sources of light remains rings of light and reflections).
These most modern multifocal lenses also create several focal points in the eye. They are sufficient for vision up close and far, as well as the intermediate area. Thanks to them, you can see well even as close as 60 to 80 cm. Besides that, they also correct night visibility. In our practice, we use only the newest generation of multifocal lenses.
There are several available methods for correcting presbyopia. All of the procedures can be performed as outpatients and are painless for the patients.
Monovision is the proper method for those of an advanced age, who is doing well with their distance vision eye and the near vision (before the operation a simulation is run using contact lenses).
A replacement lens is necessary if the calculation does not match the laser correction or the patient is over 50 and his natural lens is already slightly blurry (beginning of a cataract).
In the case of refraction lens replacement, the natural lens is removed with the help of a controlled ultrasound computer and replaced with a suitable artificial lens.
At SwissLaser, we use the most modern multifocal lenses (trifocal lenses), which allow good vision near and far and perfectly covers the intermediate distance between near and far (middle area).
In just a few days after the operation, the patient will enjoy good vision and will not need his glasses.
If eye defects remain after the lens replacement, they can usually be corrected by a laser procedure.