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LASIK

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LASIK, which stands for laser-assisted in situ keratomileusis, is a type of refractive surgery. This procedure is used to correct vision problems like myopia, which is nearsightedness. It also treats hypermetropia, or farsightedness, and astigmatism. An ophthalmologist performs this surgery to change the shape of the cornea. The cornea is the clear layer at the very front of the eye. By reshaping this layer, the eye can focus light more accurately.

MEL60-UOC
MEL60-UOC

Before any surgery, a doctor must perform a detailed pre-operative screening. They need to ensure the patient is a suitable candidate for the procedure. A doctor uses a pachymeter to measure the thickness of the cornea. They also use a topographer to map the surface contour of the eye. This topographer uses low-power lasers to create a topographic map. This map helps the surgeon identify astigmatism or irregularities like keratoconus. The surgeon uses this data to calculate exactly how much tissue to remove. Patients may also take antibiotics or sedatives to prepare for the operation.

During the surgery, the doctor follows a precise mechanical process. First, they use a microkeratome, which is a blade device, or a femtosecond laser. This tool creates a thin flap in the cornea. The surgeon leaves a hinge at one end of this flap. Then, the flap is carefully folded back to reveal the corneal stroma. The stroma is the middle section of the cornea. Next, a computer-controlled excimer laser is used. This laser performs laser ablation, which means it vaporizes microscopic amounts of the stroma. Once the reshaping is finished, the flap is repositioned. The flap acts as a natural bandage and adheres without stitches.

There are different ways to perform this surgery. One variation is called wavefront-guided LASIK. In this version, the surgeon uses a wavefront sensor to guide the excimer laser. This helps correct more than just simple nearsightedness or astigmatism. It aims to address higher-order aberrations to create a more optically perfect eye. Another advancement is topography-assisted LASIK. This method is intended to increase precision and reduce side effects during night vision. The first topography-assisted device received FDA approval in September 2013.

The history of this technology involves many important discoveries. In the 1950s, José Barraquer developed early techniques in Bogotá, Colombia. He used a microkeratome to cut very thin flaps in the cornea. Later, in 1979, researchers at IBM discovered the capabilities of the excimer laser. They found that a 193 nm wavelength could etch organic tissue with extreme precision. In 1983, Steven Trokel suggested using this laser for eye surgery. He found the laser incisions were much smoother than older diamond knife methods. Gholam A. Peyman later applied for a patent for this procedure in 1985.

LASIK has been used by millions of people around the world. Between 1991 and 2016, more than 40 million procedures were performed globally. In the United States alone, roughly 9.5 million people have had LASIK. The FDA has approved the procedure for people aged 18 and older. However, the American Academy of Ophthalmology suggests waiting until age 21. This is because vision needs to be stable for at least one year. Most patients recover quickly and return to activities within one or two days.

After the surgery, patients must follow specific postoperative care instructions. They are usually prescribed antibiotic and anti-inflammatory eye drops for several weeks. To protect their eyes, patients might wear dark eyeglasses or protective goggles. They must also use preservative-free tears to keep their eyes moisturized. Sometimes, a doctor will place a bandage contact lens on the eye. This lens is typically removed after three to four days to aid healing. Proper care is essential to minimize the risk of complications after the procedure.

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