Refractive surgery is a surgical procedure to correct the refractive power of the eye. It is done to get rid of glasses and contact lenses or to reduce the number/ power of glasses. Refractive surgeries are used to treat eye errors such as myopia (far-sightedness), hypermetropia (near-sightedness), presbyopia, and astigmatism.

WHO IS ELIGIBLE FOR THE SURGERY?

This surgery can only be done on patients above the age of 18 years with stable power of glasses. Eye surgeons decide on the available options only after proper investigation of the eyes.

CORNEA BASED REFRACTIVE SURGERY

The power of glasses can be corrected with the help of laser and it is further divided into 3 types.

A. PRK (Photorefractive Keratectomy- Surface Procedure)

In this procedure, the topmost layer of the cornea, also known as the epithelium, is carefully removed. This is followed by further processing with an excimer laser, which reshapes the surface of the cornea. This improves the patient's refractive power. Contact lenses are worn for a few days to allow the eye to heal. Through PRK, the corneal epithelium is removed, allowing cells to regenerate after surgery. The epithelium is very thin and usually returns to normal within 3 days.

B. LASIK (flap based procedure)

A flap (100-120 microns thick) is created in the upper layer of the cornea. This flap can be created in two ways.

1. Microkeratome: A microkeratome is a precision surgical instrument with a blade designed for creating the corneal flap in LASIK surgery.
2. Femtosecond laser: It is a special laser that precisely creates the flap on the cornea. A separate machine is required for its processing. Femtosecond laser assisted LASIK is also known as Femto- LASIK/bladeless LASIK.

After the flap is created by either of the above two methods, and placed over the remaining corneal bed. At the end of the procedure, the flap is placed back on the corneal bed or surface. And the patient is discharged home with medication.

C. LENS BASED SURGERY

(PROCEDURES IN EXCEPTIONAL SITUATIONS IN NON SUITABLE CANDIDATE FOR LASIK)
Lens-based surgeries include an 'intraocular' procedure to correct the number of glasses. The types are as follows:

1. Implantable Collamer Lens (ICL):-In this surgery, an artificial lens is placed in front of the original lens in the eye.
2. Refractive Lens Exchange :-The natural lens of the eye is removed and replaced with an artificial intraocular lens of suitable capacity.