PRK and Trans-PRK. Laser correction of myopia and astigmatism

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PRK, or photorefractive keratectomy, is one of the first methods of laser vision correction. It was already used at the end of the 80s. A non-contact variant, the Trans-PRK method, was also created. PRK and Trans-PRK laser treatments are used to correct myopia, astigmatism and slight hyperopia.

What is PRK?

PRK is one of the oldest methods of laser vision correction, practiced since 1987. PRK abbreviation comes from English (photorefractive keratectomy) and means photorefractive keratectomy. It was the standard method of refractive laser surgery, which has been replaced by LASIK treatments over time. Currently, however, there is a noticeable trend of returning to photorefractive keratectomy. The PRK method has undergone a number of modifications and in many respects is as safe or even in some cases safer than the LASIK technique.

During the PRK procedure, the surgeon mechanically removes the outer layer of the corneal epithelium, and then, using an excimer laser, properly shapes the cornea, eliminating the vision defect. In the case of the Trans-PRK method, the first stage of the operation has been modified – instead of manual removal of the epithelium, a laser is also used here, which reduces pain and causes faster healing.

Photorefractive keratectomy and its variants

PRK is a method of surface vision correction, the use of which covers defects such as myopia, farsightedness and astigmatism. The main branch, or rather an extension of this method, is Trans-PRK. On the basis of photorefractive keratectomy, other variants of laser vision correction procedures with various applications were created.

  1. PRK – a standard method of keratectomy for the correction of: myopia in the range of -1,5 to -7 diopters, astigmatism not exceeding 5 diopters, less often hyperopia up to a maximum of +4 diopters. It is divided into two stages: manual and laser. Convalescence is longer than after LASIK treatments.
  2. Trans-PRK – a non-contact method safer than the standard PRK, entirely performed with an excimer laser. Among the surface methods it is the most precise and is associated with less pain. It is rarely used to treat farsightedness, but it is recommended for the treatment of corneal scars and haze.
  3. LASEK – this is a variant of PRK, in which an alcohol solution is used to soften the cornea before moving the surface layer of the cornea. An epithelial flap is then prepared and can be reused. After the procedure, the tilted epithelial flap moves to its original position, if possible. LASEK has a higher risk of corneal haze during the healing process compared to PRK.
  4. EBK-keratectomy The Epi-Bowman is a modification of the PRK and LASEK methods, as a special separator is used to remove the corneal epithelium. It does not affect the Bowman layer or epithelial nerves, and the healing process is accelerated. However, as in the LASEK method, epithelial haze may form. The advantage of EBK is the lack of the need to use metal tools and chemicals. This method guarantees the patient comfort due to the short recovery time and less pain after the procedure.

Check how to choose a method of laser vision correction.

Standard PRK treatment prices They start from about PLN 2100 for one eye, while for Trans-PRK we will pay an average of PLN 2500-5000, depending on the office.

Preparation for PRK or Trans-PRK treatment

The first stage of preparation for PRK or Trans-PRK laser vision correction surgery is patient qualification, i.e. medical history and appropriate tests. Any contraindications to the procedure should be taken into account here.

Once your surgery is scheduled, follow your doctor’s instructions. It is important to replace contact lenses with glasses. Usually for hard lenses four weeks before the procedure, for soft lenses for two weeks and for soft lenses for three weeks before the procedure. 3 hours before the procedure, we give up alcohol and refrain from reaching for alcohol drinks also for the next two days. We also avoid using face cosmetics on the day of the surgery.

PRK and Trans-PRK treatments – course

In many respects, the course of PRK and Trans-PRK procedures is similar, but in the latter case there is less interference in the organ of vision. The first step is to prepare the patient for the operation – he is placed in a designated place, the face is disinfected and the patient is given anesthetic drops to the operated eye. When the anesthesia works, the eyelids are immobilized with stays and the proper procedure is started:

  1. The first stage is instillation of a fluid into the eye and removal of the corneal epithelium – in the case of the PRK method manually, and in the case of Trans-PRK with an excimer laser.
  2. The second step is to model the shape of the cornea with a laser beam. The device uses the phenomenon of photoablation and acts on the patient’s cornea in layers. The accuracy of the treatment is due to the possibility of programming the laser for a specific defect. Safety is also increased by eyetrackers, i.e. cameras that track eye movements and allow precise operation. Laser correction of one eye defect usually takes less than a minute.
  3. The third step takes place after the formation of the cornea is complete and involves protecting the eye with a soft contact lens. The entire operation usually takes several minutes.

Are you afraid of surgery? Learn the popular myths about laser vision correction.

Recommendations after PRK and Trans-PRK laser surgery

After performing the laser vision correction surgery using the PRK or Trans-PRK method, you should wait up to 5 days for the corneal epithelium to regenerate. Then you should go to a checkup, during which the protective lenses will be removed. The doctor prescribes the use of an antibiotic and steroid eye drops with a moisturizing and soothing effect. Healing is faster and the pain is less after Trans-PRK surgery. The advantages of using this method also include faster recovery of good vision, low risk of infection and smoothing the surface of the cornea.

Do medical indications after laser vision surgery belong:

  1. avoiding rubbing and pressing the eye and its surroundings;
  2. protection of the eye against dust, dust and smoke for a month after the procedure;
  3. resignation from physical exertion, especially contact and stress sports, for a minimum of three weeks;
  4. on sunny days, wearing sunglasses for a month after the surgery;
  5. rest – do not strain your eyes by spending long time in front of the monitor;
  6. avoid swimming in water bodies and swimming pools for 2-3 months;
  7. use of eye cosmetics at the earliest two weeks after the procedure.

Read also about possible complications after laser vision correction.

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