Refractive lens exchange is a surgical procedure in which the body's own lens is removed and replaced with an artificial lens. Refractive lens replacement is used for severe visual defects such as long-sightedness and short-sightedness, presbyopia or astigmatism. Artificial lenses include monofocal lenses, toric artificial lenses, multifocal lenses and accommodative lenses.
Refractive surgery is a treatment method for correcting defective vision.
Laser surgery (usually excimer laser) on the cornea, e.g. LASIK, is widely used. In some cases, however, laser treatment is not an option, so refractive lens replacement may be a sensible alternative.
This is particularly the case for patients with severe defective vision or with additional presbyopia. In a refractive lens exchange, doctors remove the natural lens and insert an artificial lens.
Two types of artificial eye lenses @ Mohammed /AdobeStock
Since the 13th century, people have been trying to correct visual defects with visual aids. The first intraocular lens was created in 1949 by Sir Harold Ridley (1906 - 2001).
During the war, Ridley observed that splinters of acrylic glass from airplane cockpits did not cause an immune reaction in the eye after crashes.
Based on this discovery, Ridley developed the first artificial lens, which he initially used successfully in secret. In 2000, Queen Elizabeth II knighted him for his services to refractive surgery.
Since then, research has made significant progress in inserting artificial lenses into the eye. Since then, many people have been able to see better again. The risk of complications with this procedure is very low.
Refractive lens replacement is useful for severe short-sightedness or long-sightedness. Especially from the age of 45-50, when your own lens can no longer see close up due to presbyopia.
By using a replacement lens, the natural refractive power (accommodative power) of the body's own lens is lost. This is why doctors only carry out refractive lens replacement after the onset of presbyopia.
The artificial lens is set to a specific distance. When replacing the lens, doctors usually select a refractive power that enables sharp distance vision. A visual aid (glasses or contact lenses) is then required for near vision , for example for reading.
Individual wishes and habits as well as the structure of the eye determine which artificial lens is used.
Ordinary artificial lenses for the eye (intraocular lenses) are usually available as monofocal lenses and adjust the refractive power of the eye. Doctors normally use them in cataract operations to treat cataracts. Here, too, they correct short-sightedness or long-sightedness.
Monofocal lenses do not compensate for astigmatism or presbyopia. Therefore, despite refractive lens replacement, a visual aid is required in many cases.
There are special artificial lenses that offer additional properties through further modifications.
Multifocal lenses, for example, cover a range of focal lengths and enable sharp vision at near and far distances.
Toric intraocular lenses, on the other hand, compensate for astigmatism.
As refractive lens replacement is often a cosmetic indication, a careful preliminary examination is particularly important.
This reduces risks and disappointment for the patient. The doctor should therefore provide the patient with detailed information in advance and clarify whether the patient is aiming to be completely spectacle-free.
The preliminary examinations before a refractive lens exchange include
In principle, refractive lens replacement corresponds to cataract surgery.
Doctors remove the natural lens and insert an artificial lens. To do this, they make tiny, self-closing incisions at the edge of the cornea (between 1.8 and 3.0 mm). The surgical instruments and the artificial lens are inserted through the incisions.
When removing the natural lens, the surgeons open the lens envelope and suck out the contents of the lens. A foldable artificial lens is inserted into the clear capsular bag, where it is stabilized with small retaining clips. You do not need to sew it on.
Depending on the refractive error and the patient's expectations, doctors insert an artificial lens with different optical properties. The lens is determined and specified in advance.
The following lenses are available for refractive lens replacement:
These lenses correct long-sightedness or short-sightedness. After refractive lens replacement, you can see clearly at a certain distance without glasses (e.g. in the distance).
Modern artificial lenses are foldable and made of high-quality materials such as acrylates or silicone. They are very well tolerated.
A UV filter is now standard, and artificial lenses with blue or violet light filters are also increasingly common. They offer the retina additional protection against harmful influences and achieve improved contrast perception (e.g. when driving).
Better contrast can also be achieved with aspherical lenses, which is useful for wide pupils and twilight. As their shape does not change, accommodation (adjustment to distance and near) is not possible. You therefore need reading glasses.
If you have astigmatismin addition to long-sightedness or short-sightedness, toric lenses are recommended. To correct the astigmatism, the doctor marks the toric lens on the cornea before the operation.
The line-shaped markings on the edge of the lens optics are important for correct positioning in the eye.
These lenses have several focal points, which ideally allows all everyday activities to be performed later without glasses.
Different multifocal lenses are available depending on your needs. You should therefore clarify with your doctor in advance at what distance you would like to see without glasses. You should also tell your doctor what your main activities are.
As there are also optical disadvantages (increased rings of light around light sources), a detailed discussion is essential.
Accommodative lenses are suitable for correcting presbyopia.
The principle works like this: force vectors cause the lens optics to move forward in the eye when looking at a close object.
Unfortunately, this mechanism has proven to be less effective. However, compared to multifocal lenses, they have no side effects.
Accommodative lens with double optics on the first day after surgery. With this lens model, only the anterior part of the lens, which contains a particularly strong refractive power, moves forward, allowing a relatively good effect.
Refractive lens replacement is usually performed on an outpatient basis and under local anesthesia. The patient receives an injection next to the eye or anesthetic drops/gels.
The type of anesthesia used depends on individual factors. An operation without complications takes 10 to 15 minutes.
After refractive lens replacement, you will need to take eye drops regularly for several weeks. They contain a cortisone preparation, often in combination with an antibiotic, which prevents inflammation.
The overall risk of complications is very low, although your doctor must inform you about possible complications, such as the risk of infection.
A frequently occurring late complication is secondary cataract, which is caused by clouding of the capsular bag in which the artificial lens is located.
For the patient, this means a gradual deterioration in vision, which can occur months to years after the refractive lens replacement. This phenomenon occurs more frequently the younger the patient is. Doctors remove the secondary cataract easily using laser surgery.
Depending on the type of lens, there are also specific optical side effects such as
After refractive lens replacement, the patient must take eye drops regularly for several weeks. During the healing process, regular check-ups are carried out by the ophthalmologist to ensure that healing is taking place appropriately and without complications.
You should also refrain from swimming and going to the sauna during this time to avoid increasing the risk of infection. You should also avoid heavy physical work . You should also be careful not to rub the eye during the first few days.
In the long term, there is no impairment with regard to sporting activities. However, you should limit your sporting activity in the first few weeks after refractive lens replacement.
Refractive lens exchange is a reliable and safe method for correcting all types of vision defects. It is particularly suitable as an alternative or supplement to corneal refractive surgery.
A careful preliminary examination and discussion of all advantages and disadvantages is essential. Your doctor should inform you of any possible complications.
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