Conventional LASIK is a type of eye reshaping which is usually available on most types of laser and treats directly based on what glasses prescription you have. This type of laser eye surgery is effective for the majority of candidates but has a slightly higher risk of causing sight problems such as glares, halos and difficulty seeing at night than other kinds of laser treatment.
This kind of LASIK is a type of treatment which is available on the Wavelight laser. This treatment also uses the patients glasses prescription as a basis but also takes the thickness and curvature of the cornea into account. In this method laser energy is applied in a into the periphery of the cornea and as such this laser has been shown to reduce the risk of complications like halos, glare and problems seeing at night.
This type of LASIK, also known as custom LASIK, has several similarities to conventional LASIK. The main difference with the Wavefront-guided treatment is that as well as treating the patient’s refractive error, alterations which are unique in a patient’s eye, known as high order aberrations can also be treated. In this method a special kind of three-dimensional mapping is performed before you undergo surgery. This helps to identify any small problems occurring in the candidate’s optical system. If these problems are severe, then they may affect quality of vision, contrast sensitivity and night vision. If severe problems are identified by the mapping procedure, then treatment using the wavefront map can be performed.
Advanced surface ablation
There’s also a number of different methods that utilise an excimer laser in order to reshape the cornea in a similar way to LASIK, but without the need to create a corneal flap. These methods are generally known as advanced surface ablations and include treatments such as photorefractive keratectomy (PRK), laser subepithelial keratomileusis (LASEK), and epipolis laser in situ keratomileusis (Epi-LASIK). All of these methods first require the layer of the cornea, known as the epithelium to be removed and then ablation is performed by using an excimer laser.
Conductive keratoplasty (CK) is a method of eye correction which can be used to temporarily correct hyperopia or presbyopia. The CK method involves the use of radiofrequency waves in the cornea to cause peripheral corneal shrinkage and central steepening. Although research has shown the procedure has a great safety record, it’s effects are usually only temporary and regression is common after a few years.
Intracorneal ring segments
Also known as Intacs, these are used to correct patients suffering from mild myopia and keratoconus. Intacs are thin segments of plastic which are implanted into the peripheral cornea so that they flatten the cornea centrally. Once implanted, most patients report being unable to feel the rings, they are also removable and their effects are completely reversible in most cases. Visual recovery is usually slower than LASIK treatments and the results aren’t as predictable.
The Risks of laser eye surgery
Despite the fact that the majority of eye surgery is performed safely, every surgical procedure comes with risks. If the treatment requires a corneal flap then complications can occur when the flap on the front of your eye is folded back during the procedure. This can include swelling, excessive tearing and infections. The outer tissue layer of the cornea is also at risk of growing in an abnormal way. During reshaping, if the amount of tissue removed was not great enough then the clarity of vision experienced might not be as good as your expectations. This is known as under correction and those who are nearsighted are at a greater risk of experiencing this during surgery. In order to fix these types of problems, another surgical procedure may be required. Similarly, if too much tissue is removed then your vision can become over-corrected although this is much more difficult to fix than under correction. If an uneven amount of tissue is removed from the eye then it may lead to astigmatism. This happens when your eye moves too much during surgery and will require further surgery to correct.
Although it’s normal to experience dry eyes for the first few months following eye surgery, in some cases this can become severe. It’s normal to be prescribed eye drops in order to reduce discomfort but in excessive cases you may require another procedure and may require special plugs for your tear ducts. These can help to keep your eyes moist and prevent severe draining from your eyes. Difficulty seeing at night, glaring, double vision and halos can all occur after the surgery. Whilst eye drops are usually enough to handle symptoms like these, in rare cases more surgery will be required to fix these issues.