Refractive surgery has brought a revolution in myopia, hyperopia and astigmatism correction. We are already in the third decade of laser use and we can really observe that precision and safety are already here.

Dr. Chronopoulos, is refractive surgery safe today?

Refractive surgery has brought a revolution in myopia, hyperopia and astigmatism correction. We are already in the third decade of laser use and we can really observe that precision and safety are already here. With the use of this remarkable technology, we can eliminate our dependence on corrective glasses or contact lenses for good. There are two methods of effective correction of low or high degrees of myopia, hyperopia and astigmatism: PRK and LASIK. The difference between these two methods lies on the fact that, in the first, the correction occurs on the surface of the cornea, while in the second in its interior. In PRK there is some minor discomfort the first 2-3 days, while in LASIK the discomfort is insignificant and eyesight restoration happens almost immediately, on the very first day. The final result is the same in both cases.

What should someone who wishes to undergo such a procedure know, Dr. Chronopoulos?

“We are in a position to say with absolute certainty that the chances of infection from contact lenses are more than the possible complications of refractive surgery.”, the reputable scientist points out.

First of all, we are dealing with a procedure performed not only for aesthetic reasons, but therapeutic as well, with which there is a definite change in the way of life. An important role in the patient's decision to do away with glasses and contact lenses plays the trust and relationship between doctor and patient. Equally important is to have thorough preoperative tests, which will tell us if the patient is eligible for a certain procedure. Detailed and thorough preoperative tests ensure the success of the procedure. Timewise, the procedure lasts only a few minutes and it is never longer than 5 or 6 minutes for both eyes. The doctor uses local anesthesia and the patient feels no pain. It is important to note that the correction is permanent and in the very few cases where some degrees of the condition remain, then an additional laser procedure can be done to achieve full correction. An important role in the patient's decision to do away with glasses and contact lenses has the trust and relationship between doctor and patient. The 25 years of laser use allow us to say that the possibility of serious complications is negligible. Even those rare complications can be treated. We are in a position to say with absolute certainty that the chances of infection from contact lenses are more than the possible complications of refractive surgery.

The difference between these two methods lies on the fact that, in the first, the correction occurs on the surface of the cornea, while in the second in its interior.

Can presbyopia be corrected today?

Presbyopia today is outside the scope of refractive surgery and is the field where the ophthalmologists' interest is focused. The problem lies in the fact that, if we try to correct presbyopia, we unavoidably interfere with distant vision as well, which results in the patient's not having good eyesight in the distance; so we enter a cycle of procedures without end and with no effective result for the patient. Therefore, as things stand, we are not yet in a position to say that we have found a solution to correct presbyopia.


Published in the newspaper

To Paraskinio

on 1 April 2010

  
       Normal Vision                           Vision with Astigmatism

Astigmatism

When the cornea is not round but elliptical, light focuses on many points on the retina, which results in blurry close and distant vision. Astigmatism can coexist both with myopia and hyperopia.

Learn more about astigmatism and vision restoration with astigmatism laser.

News and Information on Astigmatism

Information on Astigmatism Laser

  
     Normal Vision                     Vision with Hyperopia

Hyperopia

In this condition, it is close vision that is mainly affected, but distant vision can as well, because the axial length of the eye is small in relation to the curvature and the refractive strength of the cornea. The light rays focus behind the retina which results in an effort by the hyperopic person to continually adjust his vision, which, after some time, is no longer feasible.

Learn more about hyperopia and vision restoration with hyperopia laser.

Xerophthalmia laser   

What is xerophthalmia?

Our natural tears protect our eyes and moisten them; this is necessary for a clear vision without irritations. Some people don't produce a normal quantity of tears or have problematic quality of tears, which cause the eyes to be dry and easily irritated, to be stinging and in pain, while vision may often become blurry. In some more severe cases, xerophthalmia might even be dangerous for the eye.

What are tears needed for?

The thin layer of tears of the human eye is a very complex fluid. It is excreted from various glands around the eye. It has mechanical and lubricating action and protects the eye from damaging bacteria, allergens and others infectious substances. This layer is renewed every time we blink. Our tears also have a functional role, i.e. our vision is clear only if the tear layer is intact. It is important to note that besides eye moisturizing, tear production is a reflex to external stimuli like injuries or intense emotions. However, these reflex tears help very little in mitigating xerophthalmia and that is the reason why people with “wet” eyes may often feel irritation.

What is the structure of the tears?

Tears consist of three layers. The mucus layer covers the cornea (the outside surface of the eye) by creating a low agglutination with it, so that the tear can remain on the eye. The middle layer is called aqueous layer, provides moisture and carries oxygen and nutrients to the cornea. This layer is 98% water along with small quantities of sodium chloride (salt), proteins and other ingredients. The outer lipid layer creates an oily membrane that covers the lacrimal layer and protects it from evaporation. Tears are produced in many glands around the eye. The aqueous layer is produced in the lacrimal gland, which is situated in the base of the upper eyelid. Many small glands between the walls of the eyelids produce the mucus and the lipid layer. With every blinking the eyelids spread tears on the eye. Excess tears flow towards two small ducts at the edge of the eye near the nose. These ducts lead to lacrimal tubes which end up in the nasal cavity. Communication between tear ducts and nasal cavity is the reason why, when we cry, we have a runny nose.

Who is affected by xerophthalmia?

Xerophthalmia syndrome has many causes. One of the most common causes is aging. As we grow older, our body produces less lipid substances – 60% less in the age of 65 compared to the age of 18. This is more evident in women, who tend to have drier skin than men. This lack of oil affects the tear layer. Without the oil needed, the lipid layer cannot cover entirely the other layers, which evaporate faster and leave some areas of the cornea dry. There are many other factors, like heat, dryness in the atmosphere and wind, high altitude and cigarette smoke, that also cause xerophthalmia. Many people feel that their eyes are dry when they read or work at the computer. Frequent breaks for blinking can moisturize the eyes and alleviate the symptoms. Contact lens users may also suffer from dryness, since contact lenses absorb the lacrimal layer, creating a long-term formation of protein sediments on the lens. Furthermore, some medicines, thyroid problems, vitamin A deficiency and diseases such as Parkinson's, lupus erythematosus and rheumatoid arthritis, Sjogren's syndrome (except for xerophthalmia that causes xerostomia and dryness of the mucous membrane), and Mickulizc syndrome can also cause dryness. Women often present dryness problems during menopause, due to hormonal changes. In addition, after a stroke, it has been observed what is known as lagophthalmos, that is the inability to shut the eye properly, which results in more rapid evaporation of tears and xerophthalmia.

What are the symptoms of xerophthalmia?

Xerophthalmia symptoms are foreign object sensation, itching and burning sensation. These symptoms are similar to those of chronic conjunctivitis, but a clinical exam can show the cause of the problem. Our eyes might be slightly red, without eye gums. They make us suffer without understanding why. The cornea might present pigment epitheliopathy, that is small lesions like point scrapes. In more severe cases that haven't been treated, there is a chance to lose the eye, if there is an infection (keratitis) or of corneal melt in case of total lack of tears.

Simple irritation
Burning sensation
Redness
Itch – Sustained sensation of sand in the eyes
Blurry vision that improves with blinking
Increase in symptoms after reading, watching TV or working at a computer
Difficulty in wearing contact lensesLacrimation
Lacrimation
Intense eye irritation from smoke or wind

How can xerophthalmia be diagnosed?

The ophthalmologist can diagnose xerophthalmia in the slit lamp and ascertain the quantity of tears produced. Sometimes, tests that measure tear production are necessary. Among these, Schirmer's Test is included, where the ophthalmologist places small paper filters inside the eyelids in order to measure the quantity of tears produced.

How is xerophthalmia treated?

Xerophthalmia treatment includes local use of eye drops and ointments without prescription that relieve the eyes; for example, artificial tears with similar composition to the natural ones that are preservative free.

It is important to know that all tear products are not the same and the needs of the patients are a little different in each one. Some of these products are aqueous and relieve the symptoms for a short time. Artificial tears that are preservative free are recommended more often, since they offer more relief and don't cause further irritations. You should avoid products that remove redness or “whiten” the eyes, because they don't have the necessary moisturizing quality and often make the problem worse. In more serious cases, the ophthalmologist may place special caps in the lacrimal punctum to prevent natural and artificial tears from draining out of the eyes (with either temporary collagen caps that will be absorbed or permanent silicone caps).

There are also cases when the doctor provides the patient with special soft contact lenses that help retain moisture. Furthermore, if the eyelids don't close during sleep, the use of protective covers for the eyes is recommended, in order to minimize tear evaporation.

In any case, people who suffer from xerophthalmia should avoid exposure to dust, pollen, smoking and other environment polluting factors. In addition, their stay in a very hot environment will worsen xerophthalmia. On the other hand, interior moisturizers can help since they add moisture that helps against tear evaporation.

There are also simple everyday habits, whose change can improve the problem of xerophthalmia. For example, 8-10 glasses of water daily can keep our body well hydrated and remove metabolized waste. Also, a conscious effort to blink more often, especially when we read or watch TV can help significantly. Finally, it is advisable to avoid rubbing the eyes which might worsen the problem.

Remember:Your ophthalmologist is the best source for responsible answers on issues related to your eyes and their health. Under no circumstances is information taken from our website intended to replace him. Seek your doctor for complete information.

Eyeclinic's gem, recognized worldwide as the top Excimer Laser with the most advanced technical features, the fastest Laser source at 500Hz that reduces treatment time (less than two seconds per diopter) and performs quick refractive procedures. It has the fastest and most precise Eye Tracker with a reaction time of 2 ms (millisecond), it is able to track eye movements of all dimensions and recalibrates all the laser shots according to the micromovements of the eye, thus correcting the entire optical zone in a precise and uniform way. Because of its advanced technology, it incorporates OLCR online non-contact pachymetry, perfect for safe, real-time control of the thickness of the flap and the tissue that remains before the start of the treatment, as well as the changes in the thickness of the cornea, with continuous measurements before, during and after the procedure. Allegretto EX-500 transcends its role and is capable of increasing and reducing the thermal load on the cornea, creating an even smoother sculpting of the ocular surface, in combination with the revolutionary pulse technology of the FS-200 Femtosecond laser (creation of a smooth and very thin flap without the use of a blade). It is the new generation of correction for myopia, astigmatism, hyperopia, and corneal surface deterioration.