REFRACTIVE SURGERY
By changing the focal length of the eye, refractive surgery aims to give near- and far-sighted people spectacle independence. This can be done through manipulating the corneal surface with LASER (LASIK and PRK), implantable contact lenses (ICLs) or removing the eye's natural lens and replacing it with an appropriate artificial one. Myopia (nearsightedness), hyperopia (farsightedness) and presbyopia or astigmatism are types of refractive errors that can be corrected through refractive surgery.
The cornea is a translucent protective covering of the outer part of the eye and works in conjunction with the sclera, the white of the eye, to fight against germs and harmful bacteria that can damage the entire structure. The cornea is also essential in the filtration of harmful ultraviolet light. Light refracts as it bounces off the cornea's curved edges and determines the eye's focusing power. Diseases and infection can damage the cornea and affect the refraction of light.
LASIK (Laser-assisted in situ keratomileusis) surgery
LASIK (Laser-assisted in situ keratomileusis) is a refractive procedure carried out to resurface an irregularly shaped cornea. This refractive surgery involves the use of a special cutting laser to correct the shape of the cornea. After numbing the eyes with eye drops, surgeons place a suction ring over the eye and cut inside the corneal flap. They create a flap in the front of the eye to access and reshape the corneal tissue. Using a laser, surgeons remove corneal tissue and recontour the remaining parts before folding the flap back in place and allowing it to rejuvenate without stitches.
PRK (Photorefractive keratectomy) surgery
PRK (Photorefractive keratectomy) is a refractive procedure that aims to redesign the cornea to refract light correctly. Like LASIK, when performing PRK surgery, doctors numb the eyes with anaesthetic drops and place a suction ring over the area to keep it open. Using a buffing tool or surgical equipment, the doctor begins by unpeeling the first layer of the cornea, the epithelium, to reach deep underlying layers. While the patient focuses on a targeted light, surgeons use an excimer laser to recontour the cornea. By doing this, microscopic tissue is removed to refine the corneal shape and its edges for perfect vision.
Implantable contact lenses (ICLs)
Inserting implantable contact lenses is a relatively painless and straightforward procedure. ICLs can be implanted in front of or before the iris, the coloured area of the eye. ICLs slip over the eye and correct vision naturally. Using a laser, surgeons create a hole in the iris for fluid to move from the back part of the eye (posterior chamber) to the front region of the eye (anterior chamber). A new lens is inserted through the cornea before the eye lens, behind the iris. The tiny incision within the cornea is left to heal without the need for stitches.