Wednesday, 19 February 2014 12:03

Femto Lasik and Conventional LASIK

LASIK METHOD (Conventional Lasik and Femto Lasik):

This method is effective and painless. It is used to correct medium to high degrees of myopia and astigmatism, while it is the only method to correct hyperopia.

The advantages of this method are many, because treatment occurs on the corneal layer after creating a protective tissue (flap). There are two ways to create the flap.

femto lasik
Conventional LASIK with mechanical microkeratome
femto laser μυωπία femto lasik femto lasik

Femto-Lasik με Femtosecond laser

Postoperative medication lasts only ten days, while the vision is fairly good from the very first day. The degree of correction is calculated by specialized software.

There is conventional LASIK, where the flap is created with a mechanical microkeratome and FEMTO-LASIK, where it is created with a femtosecond laser. With the new Femtosecond laser technology, the surgeon is able to exclusively use laser during all the stages of the surgery, even the first stage, so that the LASIK procedure can be completed without the need to apply a “scalpel” in any of the stages. Its name is derived from the number of pulses per second in which this particular laser operates.

In particular, microscopical, rapid laser pulses are used, which operate in the infrared zone of the light spectrum and, in combination with the extremely short time of activity and the slight amount of energy, they achieve photodisruption of the tissue on which they fall (in our case, the cornea). Photodisruption is visible in the form of a bubble, which, in the end, is the force with which the femtosecond laser cuts the tissues. Subsequently, the doctor creates the flap by lifting the tissue of the cornea towards the back, at the point where the bubbles have been formed due to the light pulses. The creation of the flap lasts merely 15 seconds. That is the time when the surgeon can move on to the second stage of the procedure, that is the full correction of the refraction and the restoration of vision.



Femtosecond laser lasik, virtual laser procedure (youtube)
Femtosecond laser and cataract procedure


Published in Publications
Wednesday, 19 February 2014 10:57

Developments in Refractive Surgery

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 impressive technology, we can forever eliminate our dependence on corrective glasses or contact lenses.

There are two methods of effective correction of high or low degrees of myopia, hyperopia and astigmatism: PRK and LASIK (conventional LASIK, where the creation of the flap is done with a mechanical microkeratome and FEMTO-LASIK, where it is done with a femtosecond laser). The difference between these two methods lies in 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. 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. The most important part of a refractive surgery is thorough preoperative tests, which will show us if the patient is eligible for a procedure in that particular area. 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. 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.

Keratoconus is a non-inflammatory disorder of the cornea, which is characterized by the presence of a progressive deformation of its surface. The cornea gradually takes a “conical” shape (it expands by creating an extrusion), deforming the reflection formed in the fundus of the eye. A progressive thinning can also be observed, as well as scarring, and finally opacity in the area where the cone has formed. Despite ongoing research, the causes of keratoconus are essentially unknown. It is generally considered a genetic disease caused by multiple factors, mainly irregularities in the structure or the metabolism of various segments of the cornea. It used to be considered a rare disorder, perhaps because there weren't any diagnostic means to detect it in the early stages. Today we know that keratoconus is not so rare. There are more than 20,000 people in Greece with keratoconus (approximately 1 for every 2,000 people). It usually appears in adolescence and progresses relatively fast, while later the rhythm of deterioration decreases and stops at around 35 years of age. Physical examination does not always provide evidence for a positive diagnosis. However, keratometry can give altered parameters. The patient presents an irregular progressive astigmatism that previously did not exist. In more advanced stages, the diagnosis is easier and with the help of a slit lamp, the cornea can present the known conical form, as well as thinning and haze of its central area. Nonetheless, positive diagnosis occurs with the help of an electronic device and a test called “corneal map” (corneal topography). In this test, a 2D image of the corneal topography is taken and, based on that, we can diagnose even the subclinical forms (those that haven't presented any symptoms). It is strongly believed today that the riboflavin method can substantially delay or even stop the development of keratoconus, saving the patient from a potential corneal transplant. This method is still evolving and is called C3-R (Corneal Collagen Crosslinking with Riboflavin). Through lab tests and clinical examinations, it has been proven that it reinforces the inner structure of the cornea, stabilizing its architecture and, specifically, strengthening the bonds of the corneal collagen fibers, which are among the basic ingredients for maintaining its structure.

C3-R treatment can be done at the clinic and lasts about 60 minutes. During the treatment, drops of a riboflavin (B2) mix are instilled, which are then activated with UV rays.

Cataract is a haze of the natural lens inside the eye. This lens, which is found behind the iris (the colored part of the eye) is capable of moving and changing shape, so that it can function exactly like the lens of a camera, by focusing bright images on the retina, which, in turn, sends them to your brain. The human lens, consisted mainly of protein and water, can present some haze, in such a degree that the light and images are not allowed to reach the retina. Eye damage, certain disorders or even some medicine can cause this haze. In more than 90% of the cases, however, this haze is cause by the aging process. Cataract isn't a deposition in the eye and cannot be removed with diet or laser. The best way to treat cataract is to remove the old, hazy lens and to replace it with an artificial one. Cataract can be the cause of the blurring of clear images, the dimming of bright colors or a decrease in vision at night. It is also possible that it is the reason why reading or bifocal glasses that used to help you read or perform simple tasks, cannot help you any longer. Unfortunately, it is not feasible to prevent cataract, but only to remove and replace it with an artificial lens which can restore your vision and significantly improve quality of life. The proper time to remove cataract is when the quality of your vision starts causing restrictions in your activities and your enjoyment of life.

Modern technologies, as well as our top-ranking scientific, personnel make us capable of developing pioneering methods to treat even the most demanding eye disorders, like Inflammations, Glaucoma, Age-Related Macular Degeneration, Diabetic and Hypertensive Retinopathy, Retinal Detachment, Strabismus, Optic Neurolopathies etc., even in the most difficult of cases.

George Chronopoulos

Ophthalmologist Surgeon

Published in Publications




Τμήμα Αμφιβληστροειδούς και Ωχράς Κηλίδας