Presbyopia correction by implanting intraocular lenses
Medicine has discovered a new solution to the problem of presbyopia for patients who have to use glasses for reading after a cataract operation.
A new procedure has been available at CMO LASER since May 2015. This is the implantation of Reverso® multi-vision lenses. These lenses make reading glasses unnecessary for patients who have undergone cataract surgery and have single-vision lenses fitted.
Reverso® lenses may be implanted in patients of any age, once they have been found eligible for the procedure, of course, if the eye meets conditions similar to those required for multi-vision lenses (e.g. Restor) implanted during cataract surgery.
The eligibility test, apart from a detailed ophthalmological examination, covers additional tests, including corneal topography (mapping), examining the corneal endothelium and a UBM examination of the anterior section of the eye. During this, the ophthalmologist rules out the present of diseases or states which could cause the operation to be less effective – such as macular diseases, astigmatism above 0.75 Dpt or advanced diseases of the eye surface. The operation is not carried out on people whose anatomical conditions would hinder the safety of the procedure. Such conditions include low density of endothelium cells, weak natural ligaments of the lens or excessively shallow anterior chamber of the eye.
There is no natural accommodation in patients who have undergone cataract surgery and had single-vision lenses implanted. Patients usually have the strength of the intraocular lenses calculated in such a way that after the operation they can see well at a distance and use glasses for reading. Medicine has discovered a solution for them – additional intraocular lenses of the Add-on Reverso® Multifocal type made by the French company Cristalens.
Laser correction of presbyopia
The procedure involves removing the corneal epithelium using a special Epi-Clear tool (by Orca Surgical) and in this way preparing the cornea for the effects of an excimer laser whose beam changes its curvature to correct the sight defect. After the laser modelling is complete, a bandage contact lens is applied for a period of 5-7 days.
- The Reverso® lens is an Add-on type (or piggy-back) foldable posterior-chamber lens, implanted into the eye through a small tunnel incision in the cornea only 2mm wide.
The lens is fitted in the posterior chamber of the eye in the ciliary groove behind the iris.
This means that it is not visible in the mirror, for example
- After the operation, there is no need to apply (or later remove) stitches, for several weeks after the procedure eyedrops recommended by the doctor should be used. For the first two weeks after the operation, it is particularly important for the patient not to press or rub the eye which was operated on.
- Thanks to the multi-vision, diffractivel structure of the Reverso® lens, the retina receives a sharp image of both nearby and distant objects simultaneously.
After a short period of healing after the operation, usual no longer than a few days, the patient may see clearly e.g. the text of a book or newspaper without using reading glasses.
The full effect of the operation is usually achieved when multi-vision lenses have been implanted in both the patient’s eyes.
- The diffraction phenomenon used in the Reverso® lenses enables the formation of two focal points for light rays (near and distant), but may also result in a slight worsening of the sensitivity to contrast in some patients, particularly in bad lighting.
- Sharp close-up vision and reading without glasses usually require good lighting conditions. In some cases, reading very small print with low contrast, or in dim light, will require the patient to wear weak glasses (around +1Dpt).
- As in the case of other intraocular multi-vision lenses, some patients may experience detrimental optical phenomena after the operation, such as glare or halo effects.
This is why multi-vision lenses, including Reverso® lenses, are not recommended for people who, due to their lifestyle, profession or hobby, need very good eyesight in twilight or night conditions (e.g. they often drive at night).