internal medicine

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.

Radial keratotomy was first introduced in the United States in the 1980s. Initially it was much of an investigational procedure
with doctors operating only one eye at a time and waiting for at least 3 months to observe the results
before operating on the other eye. But the surgeons gained experience over time and now they could well operate both eyes simultaneously. Now
radial keratotomy is a minor surgery that takes about 15 to 20 minutes for each eye.

Radial keratotomy is constantly improving
owing much to the rapid advances in technology
and the fact that a number of such procedures have already been performed successfully. However
RK is not as precise as LASIK and PRK. Since
RK is less predictable
only a few surgeons now perform this procedure.

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.

The operation is performed with the patient awake and mobile; however
the patient typically is given a mild sedative (such as Valium or diazepam) and anesthetic eye drops.

Lasik is performed in two steps. The initial step is to create a flap of corneal tissue. This process is achieved with a mechanical microkeratome using a metal blade
or a femtosecond laser microkeratome that creates a series of tiny closely arranged bubbles within the cornea. A hinge is left at one end of this flap. The flap is folded back
revealing the stroma
the middle section of the cornea. The process of lifting and folding back the flap can be uncomfortable.

The second step of the procedure is to use an excimer laser (193 nm) to remodel the corneal stroma. The laser vaporizes tissue in a finely controlled manner without damaging adjacent stroma by releasing the molecular bonds that hold the cells together. No burning with heat or actual cutting is required to ablate the tissue. The layers of tissue removed are tens of micrometers thick.

During the second step
the patient's vision will become very blurry once the flap is lifted. He or she will be able to see only white light surrounding the orange light of the laser. This can be disorienting.

Currently manufactured excimer lasers use a computer system that tracks the patient's eye position up to 4
0
times per second
redirecting laser pulses for precise placement. After the laser has reshaped the cornea
the Lasik flap is repositioned over the treatment area by the surgeon. The flap remains in position by natural adhesion until healing is completed.

Performing the laser ablation in the deeper corneal stroma typically provides for more rapid visual recovery and less pain.

There is no "best" method for correcting vision errors. The most appropriate correction for you depends on your eyes and your lifestyle. You should discuss you situation with your ophthalmologist or eye doctor to decide which correction will be most effective for you.

10 Reasons for Lasik!

1. Nothing is as sweet as the freedom from the hassles and inconveniences of contacts or glasses.

2. You save money! Over the years
the costs of lenses
solutions and glasses amounts to thousands of dollars.

3. You save time! In one year
the average contact lens wearer spends nearly 60 hours wetting
soaking
rubbing
cleaning and otherwise maintaining them. This is about 2.5 whole days!

4. Imagine waking up in the morning
and being able to see the clock!

5. You get to go swimming
scuba diving and be able to see things!

6. You are able to spontaneously go camping or stay overnight.

7. You are able to take a nap when the mood strikes without first having to remove lenses. Imagine the hassle saved!

8. You will be able to see while putting on makeup or shaving
no more squinting!

9. You will be able to participate in outdoor sports without glasses that fog or get splashed with rain or lenses that dry out in the wind.

10. And most important of all
you w ill be able to avoid the negative consequences of long term contact lens wear!

Clinicians wishing to undertake laser eye surgery should ensure that patients understand the benefits and potential risks of the procedure. So the better you understand your LASIK surgery
and what happens after your surgery
the better prepared you'll be for your surgery. Patients should be counseled on the potential risks and benefits of LASIK
then make an informed decision. No matter what your motivation may be
the decision to have eye improvement surgery is no small task and it should be considered carefully. If you decide Lasik surgery is for you
consulting your eye doctor is critical to making an informed decision.