A cataract can only be corrected with the help of a surgical correction. Cataract surgery is one of the most common surgical procedures and can usually be performed on an outpatient basis. There are no medications for cataracts.
Whether an operation should be carried out depends primarily on the extent to which the person affected is restricted in their everyday life by their reduced visual acuity. In case of additional eye diseases (for example optic nerve or retinal diseases) it has to be clarified whether a good visual acuity can be restored despite a successful cataract operation. Many people also decide against cataract surgery at first because of fear of eye surgery in case of mild symptoms.
If the cataract is very advanced, it must be surgically corrected even if there is no prospect of better vision, because in some cases the swelling of the lens increases very quickly. This can cause the lens capsule to tear, causing lens protein to leak out and triggering an inflammation of the eye (panophthalmitis) with increased eye pressure and severe pain.
Procedure of the operation
The principle of surgical treatment of cataracts is to remove the clouded lens and insert an artificial lens instead. In contrast to the surgical technique used in the past, nowadays the entire lens is no longer removed, but the lateral and posterior lens capsule is left in the eye. The new artificial lens must have exactly the same refractive power as the original lens. Using an ultrasound device, the length of the eye and the refractive power of the cornea can be measured, which allows the lens power to be calculated.
If both eyes are affected by a cataract, only one eye is operated on at a time. The second operation is only performed once the other eye that has already been operated on has completely healed. The operation usually takes about half an hour.
In most cases, cataract surgery is performed under local anesthesia. Anesthetics in the form of eye drops are usually used. If the entire eye must be anesthetized and immobilized, an anesthetic can alternatively be injected next to the eye.
The most common procedure today is phacoemulsification. In this procedure, an incision about three millimeters long is made in the cornea, through which the lens nucleus is crushed using an ultrasound device and then suctioned out. The capsular bag of the original lens, however, remains intact - the new artificial lens is now inserted into it. Modern artificial lenses are usually made of elastic materials, which allows them to be rolled up and inserted through the small incision into the capsular bag, where they then unfold. The new lens is automatically centered and secured with the help of two elastic stirrups. The incision usually closes by itself and heals without scarring.
If the cataract is already at a very advanced stage, it may no longer be possible to shatter the lens using an ultrasound device. In these cases, the procedure of nucleus expression is used. In this procedure, the entire lens is removed through an incision about ten millimeters long and replaced by an artificial lens. This is then fixed by the surgeon with very fine sutures.
In the period after the operation, the treated eye is covered with an ointment bandage for better healing. Care must be taken that no soap gets into the eye when showering or washing. In addition, physical exertion must be avoided during the healing process, as well as sports and sauna visits. Reading is possible again about one week after the operation. About six weeks after the operation, a new pair of glasses can be fitted by an optician.
After cataract surgery, the artificial lens remains in the eye for the rest of the patient's life - it does not need to be removed or replaced at a later date. Lenses made of different materials are available (e.g. silicones, acrylates), which can be adapted to a certain refractive power of the eye. Before the operation, the patient must decide whether he or she wants to see clearly at a distance or close up - depending on this, "distance glasses" must be used after the operation, but not "reading glasses", or vice versa.
Certain artificial lenses can also be used, which are similar in function to varifocals or multifocals. These ensure good visual acuity both at distance and at near. The disadvantage, however, is that contrast vision may be reduced and there may be more glare (especially at night).
Until recently, hard artificial lenses were the standard in cataract treatment, but nowadays they are hardly ever used.
Since cataract surgery is one of the most common surgical procedures, complications occur only in rare cases. Nevertheless, as with any surgery, there are risks in general.
If the posterior capsule of the lens tears during the procedure, complications can result. Between the lens capsule and the retina lies the vitreous body (corpus vitreum), which consists of a transparent, gel-like mass. This presses the retina onto its support. If the posterior lens capsule tears, vitreous substance can escape through the tear, which in the worst case can lead to detachment of the retina.
In very rare cases, germs enter the eye during cataract surgery, causing a bacterial inflammation (endophthalmitis). This can lead to blindness of the affected eye.
As a consequence of the surgical removal of the cataract, a so-called secondary cataract may develop. In this case, a clouding of the posterior lens capsule develops over time. While this complication used to occur in up to 50 percent of patients, modern surgical techniques have now reduced the risk to about four percent. By means of a laser, the post-cataract opacity can be removed on an outpatient basis and painlessly, without the need for another operation. The laser treatment immediately restores full vision.