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What is presbyopia?
Presbyopia, is a condition in which, over the course of a lifetime, the eyes lose their ability to see clearly at a close range.1,2 presbyopia is due to natural ageing processes that occur slowly over many years and go unnoticed for a long time. Sooner or later, everyone is affected by presbyopia, regardless of whether they were previously shortsighted (myopia), far-sighted (hyperopia) or normal-sighted (emmetropia). However, the time course and the degree of severity vary from person to person.1
How does presbyopia develop?
The lens of the eye must adapt in order to see sharply at different distances.2 Due to its elasticity, the lens can change its shape and thus its refractive power with the help of a ring-shaped muscle called the ciliary muscle. This process is called accommodation.1 As part of the natural ageing process, the elasticity of the lens decreases, as does the strength of the ciliary muscle. As a result, the lens loses the ability to change its shape and thus its refractive power and to adjust to different distances. This creates a blurred visual impression at close range. This is called presbyopia.1,2
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What is the difference between presbyopia and hyperopia?
Both presbyopia and hyperopia have impaired near vision, but the cause is different. Hyperopia, which often occurs at a young age and is usually caused by the eyeball being too short, while presbyopia is due to the decreasing ability of the lens to accommodate due to the natural process of ageing.1,2
How does presbyopia manifest itself?
Presbyopia develops slowly over many years.1,2 If near vision deteriorates from the age of 45, the cause is often presbyopia. 2 Those affected notice that reading becomes increasingly difficult and that they have to hold the newspaper or book at a greater distance from their eyes in order to still see clearly.1,2 Their arms suddenly become too short. Also quickly tired eyes or headaches associated with reading can also be a sign of presbyopia.2
How is presbyopia diagnosed?
If there are difficulties with near vision, an examination should be carried out by an eye specialist or optician to determine the visual acuity and to rule out other possible causes, such as hyperopia.1 For this purpose, the doctor uses reading charts which are held by the patients at reading distance and thus assesses the vision and the need for correction.1 The patients direct their gaze to the reading chart while the eye specialist holds different corrective lenses in front of their eye. The patients state the correction with which they can see the sharpest.
How is presbyopia treated?
Treatment for presbyopia consists of correcting the visual impairment. The following treatment options are available:
- Glasses/contact lenses. A visual impairment can be compensated by prescribing glasses or contact lenses.1-3 Reading glasses are used exclusively to correct near vision and thus enable the wearer to see sharply at close range, e.g. when reading.1-3 In the case of hyperopia or myopia in addition to presbyopia, bifocals or varifocals can also be fitted to enable optimal near vision and distant vision with only one pair of glasses.1 The lenses of bifocals allow sharp distance vision in the upper lens area, while the lower lens area is corrected for near vision. The lenses of modern varifocals offer several different strengths within the lens, which blend continuously into each other. In this way, they enable a continuous gliding between the near, middle and distance range.1 As an alternative to glasses, it is also possible to correct defective vision and presbyopia with contact lenses, known as multifocal lenses.1
- Laser treatment. A laser is used to erode the surface of the cornea to correct the visual defect(s).4,5 If presbyopia is also to be corrected, it should be borne in mind that this will continue to change naturally with increasing age. A detailed consultation with the surgeon is therefore absolutely essential.1,4-6
- Surgery. It is also possible to replace the patient's own lens surgically with an artificial lens.1,2,4 However, an artificial lens cannot accommodate because it is rigid.2 If both the distant and near ranges are to be corrected, good results can be achieved by using multifocal lenses. But here too, correction of presbyopia is not stable and changes over the years.2 Once again, the surgeon should provide detailed information before the operation.1,5,6
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References
1. Grehn F. Augenheilkunde. Springer Berlin Heidelberg 2019.
2. Walter P, Plange N. Basiswissen Augenheilkunde. Springer Berlin Heidelberg 2016.
3. Goebeler M, Walter P, Westhofen M. Augenheilkunde, Dermatologie, HNO in 5 Tagen. Springer Berlin Heidelberg 2018.
4. Augenärzte informieren: Laserverfahren. https://augeninfo.de/cms/hauptmenu/augenheilkunde/sehen-ohne-brille-refraktive-chirurgie/laserverfahren.html, Zugriff: 03.04.2020.
5. Balgos MJTD, Vargas V, Alió JL. Correction of presbyopia: An integrated update for the practical surgeon. Taiwan Journal of Ophthalmology 2018; 8: 121-140.
6. Wolffsohn JS, Davies LN. Presbyopia: Effectiveness of correction strategies. Progress in retinal and eye research 2019; 68: 124-143.