Not long ago, the only way to correct refractive errors was wearing prescription glasses and contact lenses. Today, however, different surgical techniques have been invented which change the shape of the cornea to correct refractive errors. A common technique is treatment by laser in which the patient's quality of vision is enhanced. These techniques include P R K, Fem to P R K , Photo refractive mastectomy, E pi-LASER, and LASER.

Note that the success of refractive error correction surgeries largely depends on your understanding of the surgical method and expectation of your postoperative vision. Since its inception, Iran Noor Ophthalmology Hospital has performed refractive error correction with LASER surgery with the help of experienced Iranian ophthalmologists and the most advanced LASER surgery devices in the operating rooms of Noor Ophthalmology Hospital

What are P R K

LASER is an outpatient surgical technique used to correct hypertrophy, myopia, and astigmatism. It is one of the most appropriate and quickest refractive error correction techniques. In this method, a thin cut is made on the cornea and then, at surgeon’s order, patients look at a flashing light above their head. At this stage, laser is aimed at the corneal surface.

Advantages of P R K

Rapid recovery: Most patients can return to normal activities within one or two days. There is often no pain, and appropriate vision is obtained after 24 hours. There is greater discomfort in P R K (corneal cut) and P R K (laser).

Correction of an extensive range of myopia: Myopia of about 12 DP can be well corrected by LASER, while using P R K (laser) for high DP (more than 7) can lead to corneal opacity, reduced vision, and partial return of myopia. Moreover, P R K surgery (corneal cut) is unable to correct more than 5 to 6 DP.

Repeatability: This surgery can be repeated in cases of lower correction level by P R K, by lifting the thin layer created in the first surgery and using laser again. Like the first surgery, recovery is rapid.

Long-lasting effect of the surgery: Most studies show that the visual acuity score stabilizes within 3 to 6 months since corneal structure is slightly changed and repaired subsequently.

Preserving the normal corneal structure: The thin layer removed is completely fixed after a few days, so that it will not be displaced by blinking or rubbing the eye. UnlikeP R K (corneal cut), corneal rigidity and resistance against impact are not reduced in P R K surgery.

No opacity: Unlike P R K (laser) that is likely to cause corneal opacity in high scores, no corneal opacity is created by P R K  surgery.

No long-term need for eye drops: Unlike P R K, there is no need to control wound repair by steroid eye drops following P R K surgery. Moreover, P R K patients do not usually need medication for more than a week

 P R K

This surgical technique uses an exciter Laser to treat mild to severe myopia, mild to moderate hypertrophy, and astigmatism. Unlike P R K, no flap is removed in this method, and it is used for people with thin cornea or those in whom a flap should not be created depending on their jobs.

P R K

This method is similar to P R K and is used to treat myopia, hypertrophy, and astigmatism. This technique is used for people with a thin cornea. In this method, the corneal surface layer or corneal epithelium is softened by an alcoholic solution and then removed to expose the cornea to laser radiation. Afterward, the epithelial layer is returned to its original place.

General conditions for refractive error correction surgery by laser

    Minimum age of 18 years
    No change in the visual score for at least one year
    No unrealistic expectations of the surgery
    No uncontrolled diabetes
    No connective tissue disorders
    No history of corneal herpes simplex
    No glaucoma or cataract
    Not using certain medications .
    No pregnancy or breastfeeding


Key points before surgery

    Washing eyelids and eyelashes the night before surgery
    No makeup 48 hours prior to surgery
    Wearing light and comfortable clothing on the day of surgery
    Not wearing perfumes on the day of surgery
    Not using contact lenses 48 hours before surgery
    Taking tranquilizers in case of anxiety

 

Common and probable complications

 

    Dry eye
    Glaring lights
    Aura
    Reduced night vision
    Reduced clear vision
    Sensitivity to light

Probable (uncommon)

    Inflammation
    Corneal infection
    Irregular astigmatism
    Loss of vision
    Regression of the initial effects of surgery


Essential points during laser surgeries


    Watch the blinking red or green light during surgery and do not move your eyes or head.
    Depending on the type of laser used, laser surgery usually takes 10 seconds or less than a minute. Therefore, do not move your eyes while you still hear the sound of the laser.
    Do not worry about blinking because your eyelids are kept open by a device. To prevent an unpleasant feeling during surgery, do not frown nor press your eyelids.
    Keep your hands away from the surgery site because they cause contamination
 

Postoperative advice

    he first postoperative appointment is 24 hours after surgery.
    Visit your ophthalmologist at regular intervals in the first six months.
    The ophthalmologist examines the vision and condition of the eyes in the first visit.
    Avoid wearing contact and aesthetic lenses for at least three months after surgery.
    Do not use lotions, creams, or make-up around the eye for at least three days or until the physician allows you.
    Refrain from aggressive sports such as boxing, football, and karate for at least 10 weeks.
    Do not rub or scratch the eyes in the first few weeks after surgery.
    Fluctuation in vision is likely in the first few months after surgery. Vision stabilization may take 3-6 months, and you may experience impaired driving at night, glaring lights in the visual field, and aura in this period.
    To decide if a second surgery is required, you have to wait until vision stabilizes in two successive visits at least for three months.

In case of severe pain on the first night, follow these points for treatment:

    Do not worry.
    Take more analgesic.
    Rest in a semi-dark room.
    Use ice compress with a towel or a dry refrigerated cloth.
    Put in eye drops only by pulling down the lower eyelid.
    Take a shower on the second day after LASIK, and after epithelium repair and removal of bandages, which takes 3-5 days, in PRK, LASEK, and Epi-LASIK surgeries.
    Prevent water from entering the eye in the first few days.
    Use baby shampoo for washing the eyes.
    Use dry ablution (tayammum) instead of wet ablution in the first few days.
    Do not watch TV, read, work with computers, and other tasks that tire the eyes. However, these actions do not damage the eyes or weaken them again.
    Do not worry about vision fluctuation, slight burning, and headache in the first few weeks.
    Use eye drops and other prescribed medications.