Eye is one of the sense organs which are the tool for sight. Eyes can suffer from various health problems by means of infections or by sight issues. When we say sight issues, refractive errors such as myopia (nearsightedness), hyperopia (farsightedness) and astigmatism are very common which people suffer the most.
These refractive errors can be corrected with Photorefractive Keratectomy and now the advanced version of it,LASIK eye surgery.
What is Photorefractive Keratectomy?
It is a surgical procedure wherein patient’s cornea surface is reshaped with the help of excimer laser. This procedure is performed in patients with refractive errors (nearsightedness, farsightednessand astigmatism) to correct it.
What is the procedure for Photorefractive Keratectomy?
It is a simple surgical procedure which involves removal of the corneal epithelium.
Few anesthetic drops are applied on the patient’s eye in order to avoid any discomfort to the patient and the eye lids are held with the help of devices to avoid any risk of blinking.
The eye surgeon then gently removes the corneal epithelial cells.
After removing the corneal epithelial cells, laser is performed to reshape the curvature of cornea. The laser is computer operated which accurately and precisely delivers the laser pulses of UV light which removes the epithelial cells tissues and reshapes the cornea. The laser is used for less than a minute in maximum patient population
After performing laser a temporary contact lens which acts as a bandage is placed. The epithelial cells grow naturally in less than a week. After a week doctor removes the temporary bandage.
Advantages of Photorefractive Keratectomy:
Photorefractive Keratectomy is often compared with LASIK surgery, in comparison to LASIK, this laser treatment is shallow
It is preferred for people with thin cornea and there is no to minimum risk of corneal complications
Disadvantages of Photorefractive Keratectomy:
Recovery is an important aspect after any surgery, in Photorefractive Keratectomy recovery is slower
You will get the desired vision after longtime
There are more chances of infection, inflammation and blurred vision
There is more level of discomfort
What is the difference between Photorefractive Keratectomy and LASIK procedure?
Both the procedures work on the same basic principle of reshaping cornea with the help of laser. Reshaping of cornea helps light to get focused on the retina which gives a clear vision.
The main difference is the recovery time. Photorefractive Keratectomy takes a little longer to recover.
In LASIK procedure, a microkeratome or a femtosecond laseris used to develop a thin flap. The flap is lifted to remove the corneal epithelial cells and to reshape it with the help of laser. In Photorefractive Keratectomy, a thin layer of cornea is removed and then the cornea is reshaped with the help of laser.
This flap is lifted to expose the underlying corneal tissue and is replaced after the cornea is reshaped
LASEK is the varied version of Photorefractive Keratectomy. In this method, LASEK involves lifting the epithelial layer of the cornea with the help of trephine. Trephine is the surgical instrument used in this process. The lifted epithelium is preserved and is again replaced after the surgery. But this method has slower recovery rate in comparison to PRK. There is longer duration of time to get the new epithelial layer of the cells.
Photorefractive Keratectomy has higher risk of eye infection and blurred vision, this particularly happens in the starting days of surgery. It takes a longer time for the cornea to get proper vision. But it offers the advantage that the complete surface of epithelial cornea is available for the treatment.
PRK is of particular importance if the cornea is thin. It is also important if the patient has undergone LASIK once and already has a thinner cornea.
Possible complications of Photorefractive Keratectomy
The eyes are dry and are painful
Recurrent corneal erosion, detachment of corneal epithelial cells from the basement membrane
Increased sensitivity of light and longer healing duration
Increased or decrease correction of refractive errors
There can be scarring of cornea and corneal haze
Reduced visual acuity
There is scattering of light by eyes and develops glare