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Refractive Surgery – Understanding the Process

 

Refractive surgery is a modern method that rectifies vision defects, such as myopia, hyperopia or astigmatism. With the help of refractive surgery, the patient’s dependence on eyeglasses or contact lenses is eliminated. Sight deficiencies can be rectified by the remodeling of the cornea, or by the replacement of the natural lens with an artificial lens.

There is no universally valid method of correcting refractive vices. The best option should be decided after a careful examination and after discussions with the ophthalmologist. If you are considering a refractive surgical intervention, please discuss with your ophthalmologist on the life style and on the visual requirements for the definition of the best procedure for you.

Whom does it concern?

  • Patients who are more than 22-23 years old;
  • There should be proof of stagnation in the evolution of diopters in the last 18 months prior to the operation;
  • In case of female patients, they should not be pregnant and nursing;
  • They should not suffer from diabetes or other systemic disorders.
  • Depending on the thickness of the cornea, the following can be corrected: myopia of up to 7-9 diopters, hyperopia of up to 4-6 diopters or astigmatism of up to 4-6 diopters.

Which are the available methods?

PRK (Photorefractive keratectomy)

PRK is a surgical intervention used in the decrease of diopters in case of myopia, hyperopia and astigmatism. The diopter decrease operation by PRK means the definite change of the corneal shape by sculpting it with an excimer laser, which thus leads to an improvement of light focusing on the retina. It is used mainly for small errors of refraction.

The eye can be sore (swelling) for 72-96 hours after the operation. The healing process then continues for a number of days and it can vary from one patient to another. Until complete healing, refraction can vary slightly. Usually, there is a period during which the patient’s vision blurs. In some patients (especially those with higher refractive defects), these symptoms can linger to a larger or smaller extent.

What do you need to know about the diopter decreasing operation by PRK:

  1. The operation is conducted with local anesthesia, administered by drops.
  2. During the diopter-decrease operation, the patient is perfectly aware. Nevertheless, he/she cannot feel, nor see how the actual intervention is conducted, because his/her vision is very blurred.
  3. The diopter-decrease PRK means the removal of the corneal epithelium, i.e. the corneal surface layer. After the completion of the operation, the related eye is covered with a protective lens, to favor the recovery of the corneal cell layer.
  4. The ophthalmologist recommends that you rest your eyes and avoid challenging activities that may hinder healing.
  5. After the diopter decrease operation, the patient will follow a treatment, with drops, to avoid the occurrence of infections and to accelerate the recovery of the epithelium.
  6. The patient will return to periodic controls, the frequency of which will be set by the ophthalmologist.
  7. The recovery requires more time because the epithelial cell layer should be completely restored.
  8. PRK cannot rectify presbyopia, a disorder caused by the aging of the lens, the natural lens of the eye. Thus, people older than 40-50 years will continue to wear reading glasses even after their diopter-decrease operation.
  9. Risks and complications linked with this intervention:
  • shining and halos;
  • wounding of the cornea, haze;
  • infection of the cornea.

How does it work?

The epithelial cells of the cornea are removed, by scraping its surface with a metallic tool and with 20% alcohol. Next, the following corneal layer, called stroma, is shown, at the level of which the excimer laser will act. This high precision laser uses a cold light beam (ultraviolet) for remove (“ablate”) microscopic amounts of corneal tissue, which thus leads to the intended remodeling. Once the laser remodels the cornea, a therapeutic contact lens is applied, for 4-to-5 days, until the complete restoration of the epithelial cells. Eye laser surgery requires only topical anesthesia, and the eye is not wrapped (dressed) after the operation.

Femtolasik – Laser technology of the future, available now t

FEMTOLASIK joins fully the newest developments of laser applications, thus generating an increased degree of comfort during and after the intervention as such. Most of the patient continue their daily activities since the first day after the operation.

To whom is Femtolasik recommended?

The ideal candidate for Femtolasik should meet the following conditions:

  • be older than 22-23 years;
  • stable refraction for at least one year;
  • sufficient thickness of the cornea, which should allow the surgeon to create an adequately thick corneal flap;
  • present refractive errors within the following ranges: myopia between -1D and -12D, hyperopia between +1D and 6D, astigmatism of up to +/-6D;
  • not suffer from systemic diseases or autoimmune disorders (diabetes, rheumatoid polyarthritis, ankylosing spondylitis).

Steps of the treatment:

Step 1: Assessment of the state of health of the eyes.

The first step in the FEMTOLASIK treatment is represented by the calculation of the characteristic features of your cornea, with the help of refractive investigations (topography, pachymetry, pupilometer, specular microscopy), after which the physician will decide whether you are eligible for this type of treatment.

Step 2: Your customized Femtolasik laser treatment.

The intervention is conducted in 2 stages:

Stage I: the creation of the corneal flap, by the femto state-of-the-art method, which does not involve the use of the scalpel, but of the Carl Zeiss Visumax femtosecond laser, the most advanced in the world at present. Owing to the Femtosecond laser technology, the thickness of the flap can be personalized depending on the thickness of your cornea, which allows refractive surgery even in the case of thinner corneas. Furthermore, the accuracy of the flap creation with the Femto laser is considerably superior to the one with the automatic micro-keratome, instrument used in the classic LASIK.

Stage II: after the creation of the corneal flap, the ablation of the diopters is conducted with the excimer laser, by the technique of customized ablation. The operation is completed by re-applying the flap in anatomic position, and then applying a therapeutic contact lens for one days (not always).

Which are the contraindications?

  • Diabetes
  • Patients with collagen diseases, autoimmune diseases, immunodeficiency;
  • Patients with eyes diseases, such as herpes simplex or herpes zoster in medical history, severe allergies, keratoconus or ocular hypertension;
  • Patients who are pregnant or nursing;
  • Patients who are undergoing treatment with amiodarone, Accutane;

What happens after the operation?

Usually, you can return home immediately (you will need somebody to drive you, if you arrive by car). You can feel a temporary burn or sensation of foreign body immediately after the surgical intervention. You may also expect some kind of lack of viewing definition immediately after the operation, but it will be cleared by the second day. Your sight should stabilize and continue to improve within several days, although, in rare case, this can last several weeks. In most of the patients, eyesight improves immediately.

The benefit of the FemtoLasik method is that, on the second day after the operation, in general, the patient sees and feels wells. You will be asked to return for periodic controls, and a treatment based on drops will be prescribed for a specific period. Several days of rest are recommended.

Like with any other surgical intervention, you should follow always the doctor’s instructions and prescribed treatment. Moreover, it is important that you do not rub your eyes, because there is a risk of detaching/decentering the corneal flap. For any type of discomfort/postoperative complication, please contact your ophthalmologist.

 

source: Metropolitan Hospital Marketing & Communication Dept., May 2016

photo credit: bigstockphoto.com