Guide Easy For Health

Radial keratotomy (RK) is a refractive surgical procedure employed to correct myopia or nearsightedness. Radial Keratotomy came into existence by accident rather than through meticulous research. The procedure was discovered by Dr. Svyatoslav Fyodorov when he operated one of his patients who had met with a bicycle accident. The boy wore eyeglasses, which broke on impact, and the glass splinters lodged into his eyes. The doctor had to make several radial incisions in the corneal tissue in order to extract the glass. When the cornea healed, the doctor found that the boy’s eyesight was significantly improved.

In radial keratotomy (RK), a series of micro-fine incisions are made in the outer portion of the cornea with the aid of a high-precision calibrated diamond knife. The surgeon administers a local anesthetic, since the incisions are superficial and the procedure is fairly painless. The corneal thickness of the patient’s eye is measured prior to the surgery. Before the incisions are made, the diamond-edged cutting instrument is precisely set under the operating microscope. Thus by flattening the curvature of the cornea in such a manner, RK can easily correct myopia or nearsightedness. Read more…

Nowadays, it is estimated that more than 100 million people around the world wear contact lenses. These items are very popular and technology improves them daily making them even more desirable.

Why do people wear contact lenses?

There are people who wear contact lenses, instead of glasses, for esthetical reasons. They like themselves better with contact lenses than with glasses. Another reason that determines people to wear contact lenses is the cosmetic one. There is a great variety of decorative contact lenses that can change the eye’s appearance. And there are those who appreciate their practical side. They cannot play certain sports with glasses; they use devices that are incompatible with glasses etc. There is that category of people who are forced to wear contact lenses for therapeutic reasons. In their case, the contact lens is not an option. The contact lens can be a bandage in the healing process of different diseases or injuries of the cornea and it is a luxury that heals. There is also a combination between the two reasons – colour lenses with correction power which actually please a lot of persons.

The first contact lenses ever made were developed out of glass. After that, new types appeared, as the ones made of Plexiglas and the rigid gas permeable ones, but, nowadays, the soft contact lens is the most appreciated. Modern materials include silicon hydrogel or other plastic polymers like etalficon A, galyficon A, senofilcon A (used in the fabrication of Acuvue contact lenses). Rigid gas permeable contact lenses are recommended to the persons with dry eyes as these lenses contain no water that could evaporate during the wearing.

If you decide to wear contact lenses, you first have to go to an ophthalmologist, no matter what your reason may be. The doctor will be the one to decide which type of contact lenses fit your eyes best. Different factors will be considered for the prescription of a certain contact lens: the material (the silicon hydrogel is one of the newest discoveries in the field), the wearing time (daily wear, extended wear or continuous wear), the shape (spherical, toric or multifocal) and many more. Depending of the material, the contact lens can be either rigid or soft. The rigid one can be gas-tight or gas-permeable, but the soft one is always gas-permeable. There can also be a further classification made on the moisture content, on the amount of water in the contact lens. Read more…

LASIK, an acronym for Laser-assisted In Situ Keratomileusis, is a form of refractive laser eye surgery procedure performed by ophthalmologists intended for correcting vision. The procedure is usually a preferred alternative to photorefractive keratectomy, PRK, as it requires less time for full recovery, and the patient experiences less pain overall.

The LASIK technique was made possible by Dr Jose Barraquer (Colombia), who around 1960 developed the first microkeratome, used to cut thin flaps in the cornea and alter its shape, in a procedure called keratomileusis. This procedure was developed and pioneered by the world leading Barraquer Clinic, based in Bogota, Colombia.

LASIK surgery was developed in 1990 by Dr. Lucio Buratto (Italy) and Dr. Ioannis Pallikaris (Greece) as a melding of two prior techniques, keratomileusis and photorefractive keratectomy. It quickly became popular because of its greater precision and lower frequency of complications in comparison with these former two techniques.

In 1991, LASIK was performed for the first time in the United States by Drs. Stephen Brint and Stephen Slade. The same year, Drs. Thomas and Tobias Neuhann successfully treated the first German LASIK patients with an automated microkeratome.

Patients wearing soft contact lenses typically are instructed to stop wearing them approximately 7 to 10 days before surgery. One industry body recommends that patients wearing hard contact lenses should stop wearing them for a minimum of six weeks plus another six weeks for every three years the hard contacts had been worn.

Before the surgery, the surfaces of the patient’s corneas are examined with a computer-controlled scanning device to determine their exact shape. Using low-power lasers, it creates a topographic map of the cornea.

This process also detects astigmatism and other irregularities in the shape of the cornea. Using this information, the surgeon calculates the amount and locations of corneal tissue to be removed during the operation. The patient typically is prescribed an antibiotic to start taking beforehand, to minimize the risk of infection after the procedure. Read more…