Laser surgery uses an Excimer laser to reshape the cornea and so treat short sightedness (myopia), astigmatism and some cases of long sightedness (hypermetropia, hyperopia). It cannot treat presbyopia, which is the need for reading glasses when people reach their mid to late 40s. For some presybopic patients monovision is an option. This will be briefly discussed below. There are two main types of laser surgery.
- LASIK (IntraLASIK). A thin corneal flap is created with a femtosecond laser, the underlying cornea is then lasered with the Excimer laser to reshape the cornea and the flap is then replaced. The vision usually settles down and recovers over the next 4-6 hours, although complete healing takes weeks to months.
- Surface treatments such as LASEK or PRK. In these treatments the outer layer of cells (epithelium) is removed from the cornea, the underlying corneal tissue is then lasered with the Excimer laser and the epithelium grows back over the next 3-4 days and the vision gradually recovers over the ensuing days to weeks. People usually need a week off work for the surface laser treatments.
The laser treatment that is best suited to any particular person can be decided after scans to assess the corneal thickness and the shape of the cornea. Laser has been shown to treat up to -10D of myopia and up to +6D of hypermetropia (although hypermetropic -longsighted, treatments can be less successful and risk regressing). Successful outcomes in myopes are more predictable up to -8D and in all hypermertopes there is a high risk of the long sightedness returning. This is less so with the low hypermetropes up to +2D. For the laser treatment of patients who are short sighted or long sighted, but also presbyopic ie older than 45 years of age, correcting the distance vision will leave most people naturally needing reading glasses. This can be overcome in some cases by having one eye corrected for distance and the other eye corrected slightly for near – a method referred to as monovision. This can be discussed in more detail in your clinic appointment if indicated. It may be that clear lens extraction and insertion of a multifocal lens may be indicated in some presbyopic patients. Contact lenses may also be an option. The risks of laser surgery are included in the detailed consent form which is in the link below. For any questions or thoughts please make contact using the details given in the contacts page or for further information visit our FAQ page.