Treatments & Therapies

Refractive Surgery – Treatment, Effects & Risks

Refractive surgery

The term refractive surgery serves as a collective term for eye operations in which the total refractive power of the eye is changed. In this way, the patient no longer needs glasses or contact lenses.

What is Refractive Surgery?

Refractive surgery refers to all surgical procedures on the eye that lead to a change in the overall refractive power of the eye. With these procedures, it is possible to replace conventional visual aids such as glasses or contact lenses. Refractive surgery is considered effective and safe for the correction of refractive errors.

Refractive surgery began in the early 20th century. In the 30s, the first studies on modeling the cornea were made, which included experiments on radial keratomy to correct myopia. At that time, however, these procedures often had complications, such as scarring of the cornea. From 1978, radial keratomy was increasingly used in the USA and the USSR. In 1983, refractive correction using an excimer laser was described for the first time. The first treatment on humans took place in Berlin in 1987 with photorefractive keratomy (PRK).

In the following years, the further development of this method to the LASEK process followed. From 1989, keratomileusis could be combined with the excimer laser method. The new method was named LASIK (laser in situ keratomileusis).

In Germany, around 0.2 percent of all Germans were treated by refractive surgery procedures. Every year, about 25,000 to 124,000 procedures take place. The trend is rising.

Function, impact & goals

Refractive surgery is used to correct refractive errors such as myopia, farsightedness and intentionality. An axial refractive visual defect occurs when the eyeball length and the focal length of the optical system do not match. Myopia is when the eyeball is too long to refractive the eye.

On the other hand, a too short eyeball leads to farsightedness (hyperopia). If different focal points are present in different meridians in the optical system of the eye, it is a astigmatism (astigmatism). With the help of refractive surgery methods, the overall refractive power of the optical system can be adjusted in such a way that the environment appears sharp on the retina. Either the refractive power of the cornea is changed or the eye lens is replaced or supplemented by implantation. The correction of the refractive power takes place by changing its curvature.

For this purpose, the ophthalmologist uses a laser to remove tissue or make defined incisions. The intraocular pressure leads to a changed shape. While short-sightedness achieves a reduction in refractive power, farsightedness increases the refractive power. However, presbyopia cannot be corrected with the help of refractive surgery. Thus, a therapeutic restoration of this refractive error is not possible.

Nowadays, laser procedures have prevailed primarily for the application of refractive surgery. The most common method is the LASIK procedure. Using a fine femtosecond laser or a microkeratome, the ophthalmologist cuts a lamella with a diameter of 8 to 9.5 millimeters into the cornea of the eye. He then folds the epithelium to the side and treats the refractive error using laser technology. As a rule, only 30 seconds are needed per laser irradiation, but this ultimately depends on the extent of the refractive error.

The LASIK method has the advantage that patients have full vision again just a few hours after the procedure. So the cornea does not have to grow back, because it is only pushed aside during the operation. In addition, the patient feels almost no pain. The LASIK procedure is used for small to medium corrections. The visual defect range varies between +4 and -10 diopters.

Another method of refractive surgery is the LASEK procedure. In this procedure, tissue is removed from the skin. With the help of alcohol, the ophthalmologist completely removes the epithelium. After the procedure, the patient is given a wound dressing that protects the cornea. A variant of the LASEK method is the EpiLASEK method. In this method, the epithelium is lifted off with a microkeratome.

The oldest laser procedure in refractive surgery is photorefractive keratomy. During this procedure, the ophthalmologist removes the epithelium with a special planer. Subsequently, it has to re-form. It takes a certain amount of time for vision to return. Refractive surgery also includes the insertion of intraocular lenses, which are artificial lenses made of different materials that are biocompatible. They are implanted in the eye, changing its overall refractive power.

Risks, side effects & dangers

As with all other surgical procedures, there is also the possibility of risks and side effects with refractive surgery. For this reason, a detailed consultation with the ophthalmologist should always take place before deciding on an intervention of this kind.One of the most common complications of refractive eye surgery is impaired vision. This can be noticeable, among other things, by a limited view at dusk or during the dark. Other side effects include a gloss effect, the formation of halos or halogens and reduced contrast sensitivity. Sometimes the patient perceives phenomena in the field of vision. Over- or undercorrections are also conceivable after the procedure. They are caused by changing the diopters again.

In most cases, follow-up treatment is required to correct the complications. A new intervention can be helpful. Some patients also suffer from rare side effects such as eye irritation, redness or severe lacrimation.

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.