Frequently Asked Questions about
Refractive Surgery and Refractive Errors

It is important that the patient understands that there is some risk in every surgical procedure. However, in laser surgery the risk is extremely low. Laser equipment’s outstanding technology resources makes the procedure one of the safest and most precise interventions.

The goal of refractive surgery is to correct refractive errors (myopia, hyperopia, and astigmatism) to decrease or eliminate the need of glasses or contact lenses. Surgery can be performed applying different surgical techniques. The most common are LASIK and PRK.

Yes. We have facilities that can meet this need, but the patient should know that he or she will spend most of the day at the hospital.

Laser surgery is done under topical anesthesia, instilling 4 drops on the eye just a few minutes before the procedure.

Regardless of the technique used (PRK or LASIK), most patients report just a certain discomfort, sometimes they feel gritty eyes and tearful, but these symptoms disappear quickly. PRK usually causes a little more discomfort than LASIK. It is extremely important to follow correctly the instructions given by the doctor.

Your normal activities can begin the day after surgery, however, when it comes to work, it depends largely on your work place conditions.

Refractive surgery provides the following advantagens:
– Greater comfort to the patient;
– No eye dressing pad is necessary;
– No stitches are necessary;
– Anesthesia by eye drops;
– No overnight stay at the hospital;
– Average surgery length is 15 minutes, but the laser is needed only for a few seconds, depending on the patient’s need;
– The patient will be able to return to work the day after the surgery, depending on the work place conditions (no pollution) and the kind of activities performed. There are cases were, instead of refractive surgery, the solution is to remain wearing glasses or contact lenses. In about 5% of the cases of those who undergo laser surgery, a residual refractive error may remain and a new laser procedure could be needed.

Average surgery length is 15 minutes, but the laser is needed only for a few seconds, depending on the patient’s need.

Excimer Laser Amaris offers a set of unique solutions for personalized treatment of refractive errors, reducing higher-order aberrations and thereby improving visual quality after treatment. Based on the Schwind-CAM integrated software and Zernike coefficient, it is possible to study the ocular and corneal aberrations and their respective treatments (spherical aberration, coma, trefoil, quatrefoil, etc.) as well as treat aspherical profile.

Laser in-Situ Keratomileusis (LASIK) is a technique used in refractive surgery that can correct myopia, hyperopia, and/or astigmatism. However, it requires greater dexterity from the surgeon since a special surgical blade is used: the microkeratome. This technique differs from PRK because it corrects vision sculpturing an internal layer of the cornea, instead of acting on the corneal surface. Post operatively the surface to be healed is minimal, so there is little risk of corneal haze and no or very little post-operative discomfort, as well as less need for post-op medication, and vision is restored in a few days, usually within 24 hours.

Photorefractive keratectomy (PRK) corrects refractive errors removing cornea surface tissue. It is mostly used to correct low to moderate levels of myopia, hyperopia, and astigmatism. It is the technique of choice for young patients with myopia. PRK presents high level of security as one of its advantages, especially in patients with thinner corneas or slight changes in curvature.

Considering the different forms of cornea treatment using Excimer laser, the two that are applied for treating the surface opacities are: Phototherapeutic Keratectomy (PTK) and Photorefractive Keratectomy (PRK), the latter being reserved for situations where there is a need to correct an associated refractive error. PTK is used for superficial diseases of the corneal epithelium and anterior stroma as, for example, recurrent epithelial erosion, corneal scarring or corneal dystrophy. Beyond removing the opacities, it can be used to achieve a more regular cornea surface. Therefore, PTK has become an alternate procedure to Superficial Keratectomy and corneal transplants, be it lamellar or penetrating transplant. However, PTK is limited in treating medium and posterior stroma corneal diseases, and its use should be avoided if the patient has inflammatory or active infectious corneal disease.

Laser vision correction is considered to be a procedure which safely corrects up to 10, at the most 12 diopters depending on the corneal curvature and thickness. If the patient presents a higher level of myopia, other techniques are recognized to be more efficient and safe, like the implant of phakic intraocular lens. Artisan-Worst lens is the one most frequently used. This intraocular lens is implanted in the anterior chamber of the eye, a space right behind the cornea, and is fixated on the anterior part of the iris. Once in place, the lens will stay in the eye permanently, without the need for change, even in high myopias of 20 or even 25 diopters.
Surgery is performed under local anesthesia, and there is no need for the patient to spend the night at the hospital, as visual recovery takes place within 24 hours. This kind of lenses has been implanted at Sadalla Amin Ghanem Eye Hospital and at Sadalla Laser since 1995.

Myopia is a condition in which the eye is unable to see far with clarity. This is due to the shape of the myopic eye, where the image is formed before it reaches the retina. It is usually treated with prescription glasses, contact lenses or laser surgery. Corrective lenses do not cure or regress myopia, instead they compensate for the refractive error, focusing the image on the retina.

When the eyeball is smaller than it should be it is more difficult to focus near objects, having a clear image formed on the retina. Hyperopia is very common in children and can go away as their eyes grow. Hyperopia can be corrected with prescription glasses, contact lenses or, in specific cases, laser surgery.

Astigmatism distorts and clouds the vision at any distance. The majority of astigmatism cases are congenital (inborn errors) and do not change throughout life. Small astigmatism errors are common and can appear at any point in life, not requiring correction with glasses or contact lenses, unless symptoms are present. In some cases, corrective lenses for astigmatism can distort peripheral image and cause symptoms during the glasses adaptation period (dizziness, nauseas, impression that one is walking on a hill). Astigmatism correction can be achieved with corrective lenses or laser surgery.

Eyestrain or presbyopia is a natural and progressive loss of ability of the eye to focus on objects. Eyestrain typically happens after people reach their 40’s, because over time, the crystalline lens (the inside eye’s lens) loses the flexibility needed to adjust focus. Thus, people who have never used glasses, need them for reading and people who have used them often require multifocal lenses. The only people who do not need reading glasses after age 45 are myopic, as they have the sight focus naturally close.

To check the price of refractive surgery and payment conditions, please contact us by phone + 55 (47) 3481-5343.