Editing LASIK (section)

==== Pre-operative examination and education ====
In the United States, the US [[Food and Drug Administration]] (FDA) has approved LASIK for people 18 years of age and older, but the [[American Academy of Ophthalmology]] recommends people wait until age 21 because vision needs to stabilize.<ref name="FDA L">{{Cite web |date=7 November 2018 |title=When is LASIK not for me? |url=https://www.fda.gov/medical-devices/lasik/when-lasik-not-me |website=U.S. [[Food and Drug Administration]] (FDA) |access-date=16 December 2019 |archive-date=19 September 2019 |archive-url=https://web.archive.org/web/20190919022717/https://www.fda.gov/medical-devices/lasik/when-lasik-not-me |url-status=live }}</ref><ref>{{Cite web |last=Boyd |first=Kierstan |date=9 August 2024 |title=LASIK — Laser Eye Surgery |url=https://www.aao.org/eye-health/treatments/lasik |access-date=14 September 2024 |website=American Academy of Ophthalmology |archive-date=18 January 2024 |archive-url=https://web.archive.org/web/20240118162254/https://www.aao.org/eye-health/treatments/lasik |url-status=live }}</ref> More importantly the patient's eye prescription should be stable for at least one year prior to surgery.
The patient may be examined with pupillary dilation and education given prior to the procedure. Before the surgery, the patient's [[cornea]]s are examined with a [[Corneal pachymetry|pachymeter]] to determine their thickness, and with a topographer, or corneal topography machine,<ref name="Finn" /> to measure their surface contour. Using low-power [[laser]]s, a topographer creates a [[topographic map]] of the cornea. The procedure is contraindicated if the topographer finds difficulties such as [[keratoconus]]<ref name="Finn" /> The preparatory process also detects [[Astigmatism (eye)|astigmatism]] and other irregularities in the shape of the cornea. Using this information, the surgeon calculates the amount and the location of corneal tissue to be removed. The patient is prescribed and self-administers an antibiotic beforehand to minimize the risk of infection after the procedure and is sometimes offered a short acting oral sedative medication as a pre-medication. Prior to the procedure, anaesthetic eye drops are instilled. Factors that may rule out LASIK for some patients include large pupils, thin corneas and extremely dry eyes.<ref>{{cite web|url=https://www.tlcvision.com/lasik-candidate/|title=Am I a Candidate For LASIK Surgery? TLC Laser Eye Centers|website=Tlcvision.com|access-date=20 December 2018|archive-date=15 September 2024|archive-url=https://web.archive.org/web/20240915032433/https://www.tlcvision.com/lasik-candidate/|url-status=live}}</ref>