Glasses are the most common solution to correct refractive visual problems.

The advantages of glasses include:

• Easy maintenance.
• Relatively low cost.
• Versatility.

The disadvantages include:

• Change in cosmetic appearance.
• Restriction of peripheral vision.
• Interference with recreational, sporting and work-related activities.
• Easy to lose or damage.
• Continual dependence.

Contact lenses are another common solution for correcting refractive visual problems.

The advantages of contact lenses include:

• No change in cosmetic appearance.
• More freedom during recreational and sporting activities.
• Better peripheral vision than with glasses.

The disadvantages include:

• High maintenance.
• Easy to lose.
• Less comfortable for patient with dry eyes.
• More difficult to fit for patients with higher degrees of astigmatism.
• Risk of Infection.

Ortho K is a technique utilizing a series of rigid contact lenses to progressively flatten your cornea, in order to treat Myopia.

The advantages include:

• The effects are reversible.
• The procedure is suitable for adolescents.

The disadvantages include:

• Continued dependence on part-time "retainer" lenses.
• High maintenance.
• Requires several visits with close follow-up.

Radial Keratotomy (RK) is the method of choice for treating low to moderate levels of nearsightedness. It was first performed by a Russian physician named Fyodorov in the 1970’s. He discovered that placing a number of microscopic incisions in a radial pattern on the cornea caused it to flatten. This flattening allowed light to focus more directly on the retina, thereby reducing or eliminating nearsightedness.

The number and length of the incisions determines the degree of correction attained. The incisions are invisible to the naked eye and take only minutes to perform. RK leaves approximately a three to four millimeter central area of the eye untouched, and the incisions penetrate approximately 90% of the cornea.

Astigmatic Keratotomy

A variation of RK, called Astigmatic Keratotomy or AK, is used to correct Astigmatism.

Limbal Relaxing Incisions (LRIs) are a modification of radial keratotomy and are often performed with RK or Cataract surgery. To treat Astigmatism, the cornea must be made more spherical or uniformly curved. Rather than flattening the entire cornea as with RK, LRIs are placed at the very edge of the cornea (the limbus) at the steepest curves. This causes the cornea to relax and become more round.

In the early 1980’s, researchers found that IBM’s new Excimer laser, used initially for etching computer chips, had refractive surgery applications as well. Unlike other lasers that tend to damage surrounding tissue, the "cold" light from the Excimer laser created no thermal damage and left a very clean margin.

Ultraviolet light and high energy pulses lasting only a billionth of a second disrupt the molecular bonds between the corneal cells with accuracy up to 0.25 microns. The beam of the Excimer light is so fine, it would take over 200 pulses to etch through a single strand of human hair. The first Excimer laser procedure to correct nearsightedness was done in 1988. Since those early days, the Excimer laser has undergone many refinements. Excimer laser technology has added more precision and predictability to altering the shape of the cornea.

LASIK is used to correct Myopia, Astigmatism and Hyperopia.

Laser in-Situ Keratomileusis (LASIK) is used to treat moderate to high levels of refractive errors. LASIK combines the computer controlled precision of the Excimer laser with the benefits of the another type of refractive surgery called Lamellar Keratoplasty.

LASIK treats the inner tissue of the cornea. First, an instrument called a microkeratome makes a flap in the outer layer of the cornea, at about 25% of its depth from the surface. Next the Excimer laser sculpts the internal corneal tissue to the correct refractive power. The corneal flap is laid back in its original position where it is allowed to dry for a few minutes. Due to the cornea’s extraordinary bonding qualities, stitches are usually not required.

PRK is the most common procedure utilizing the excimer laser. It is used to correct Myopia, Astigmatism and Hyperopia.

With PRK, no scalpels are used and no incisions are made. Your doctor prepares the eye by gently removing the surface layer of the cornea, called the epithelium. This layer naturally regenerates itself every few days. Computer- controlled pulses of cool laser light are then applied to the surface of the cornea to delicately reshape the curvature of the eye. Deeper cell layers remain virtually untouched. For most patients, only five to ten percent of the cornea is removed to obtain the desired results. The whole PRK procedure itself is usually completed in under five minutes and is painless. Since a layer about as slender as a human hair is typically removed, the cornea maintains its original strength.

If you’re over forty, wearing glasses or contacts and have been told that you're not a candidate for RK or LASIK, there is another choice. Clear Lens Replacement (CLR). In this procedure, the crystalline lens is removed and replaced with an intraocular lens. Unlike other procedures that change the shape of the cornea, your vision is corrected by changing the focusing power of the lens.

The eye is like a camera. The lens of a camera can be removed and replaced with other lenses of various focal distances. With CLR, your new intraocular lens power is selected to provide you with a focus based on your needs. Most patients prefer clear distance vision, while others want to comfortably read a menu or a computer screen.

Intraocular lenses, commonly called IOLs, may be one of the most important ophthalmic developments in the past 30 years. These tiny prescription lenses are placed inside the eye during cataract or clear lens replacement surgery (CLR), replacing the eye’s natural lens (called a cataract when it becomes clouded). Prior to the development of IOLs, cataract patients were forced to wear thick “coke bottle” glasses or contact lenses after the surgery. They were essentially blind without their glasses.

Today, patients receiving IOLs often enjoy the best vision of their lives. Thanks to sophisticated formulas used to calculate the corrective prescription power of the lens, the IOL not only replaces the need for thick glasses, it can also correct the eye’s existing refractive error.

There are two basic types of IOLs: foldable and hard. Foldable lenses are made of silicone or acrylic and can be rolled up and placed inside a tiny tube. The tube is inserted through a very small incision – less than 2.5 mm in length. Once inside the eye, the IOL gently unfolds. Hard plastic lenses are appropriate in certain circumstances determined by the surgeon. Since they cannot be folded, they are placed through a slightly larger incision.

New developments…

Lens implant surgery has become so advanced in recent years that its benefits have been extended to healthy eyes. Phakic lenses (implanting an IOL without removing the eye’s natural lens) are an option that will soon become available to young patients who may not be candidates for other refractive surgery options. And CLR, a procedure available today, gives patients over the age of 40 the option to improve their vision without glasses and avoid cataract surgery later in life.

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