Vision correction surgery, also known as refractive and laser eye surgery, refers to all surgical procedures used to treat vision problems. This field has made great progress in recent years. Refractive and laser eye surgery have resulted in better vision for many patients.
Image source: Zhanku Hailuo
Most vision correction surgery reshapes the cornea (the clear part that covers the surface of the iris) so that light passes through the cornea and focuses on the retina at the back of the eye. Other surgeries work by replacing the natural lens.
1. LASIK (laser excimer laser in situ keratectomy)
LASIK is suitable for people with nearsightedness, farsightedness, and astigmatism. Doctors reshape the tissue beneath the cornea so that it focuses light correctly. LASIK differs from other surgeries by opening a flap of skin on the surface of the cornea to reach the underlying tissue. Doctors can also use a type of computer imaging technique (wavefront technology) to generate clear images of the cornea as a guide.
In Epi-LASIK (microkeratome laser subepithelial keratomileusis), the doctor separates the thin layers of the cornea, reshapes the cornea with a laser, and uses Protection is provided by a soft contact lens, which supports the flap while the cornea heals.
2. PRK (Laser Optical Keratectomy)
PRK is used to correct mild to moderate nearsightedness, farsightedness, and astigmatism. Like LASIK, surgeons use a laser to reshape the cornea. But this surgery only affects the surface of the cornea, not the underlying tissue. Doctors may also use computerized imaging of the cornea.
Image source: Zhanku Hailuo
PK (radial keratotomy) used to be a common method for correcting myopia. However, with the advent of more effective laser eye procedures such as LASIK and PRK, this method is now rarely used.
3. LASEK (laser laser subepithelial keratomileusis)
LASEK is similar to PRK in that the doctor cuts a flap, uses an alcohol solution to loosen the tissue, uses a laser to reshape the cornea, and then uses a soft contact lens to support the skin while the eye heals valve. This method can treat nearsightedness, farsightedness, and astigmatism.
The same is true for Epi-LASEK (Micro-Excimer Laser Subepithelial Keratomileusis). Doctors cut a small flap in the cornea, use an alcohol solution to separate the thin layers of tissue from the cornea, and then use a laser to reshape the cornea. It is also protected with a soft contact lens, which supports the flap while the cornea heals.
4. RLE (Refractive Lens Exchange) and PRELEX (Multifocal Lens Replacement)
RLE stands for Refractive Lens Exchange, also known as PRELEX, Clear Lens Extraction (CLE), Refractive Lens Replacement (RLR). As with cataract surgery, the doctor makes a small incision at the edge of the cornea to remove the natural lens and replace it with a silicone or plastic lens. This method can correct deep farsightedness or nearsightedness. Patients with thin corneas, dry eyes, or other minor corneal problems have worked well with this method. LASIK or LASIK-related surgery can be used in conjunction with RLE to correct astigmatism.
PRELEX is used to treat people with presbyopia or a loss of elasticity in the eye. The doctor removes the natural lens and replaces it with a multifocal intraocular lens.
5. Intacs (implantation of stromal rings)
Intacs are also known as intracorneal stromal ring segments, or ICRs. The doctor makes a small incision in the cornea and places two crescent-shaped plastic rings around the outer edge. These two rings flatten the cornea, redirecting the way light enters and focuses on the retina. ICR was once used to treat myopia, but has been replaced by laser surgery and is now used to repair keratoconus, the thinning of the cornea and vision loss caused by the irregular shape of the cornea.
6. IOL implantation
Intraocular lens implantation is primarily reserved for patients whose myopia is too deep to receive LASIK and PRK. The doctor makes a small incision at the edge of the cornea and attaches the lens to the iris or behind the pupil. Unlike RLE, this procedure preserves the patient’s natural lens.
7.AK or LRI
AK or LRI is short for astigmatic keratotomy, which is not a laser eye surgery but a surgical procedure to correct astigmatism. In astigmatism, the patient’s eye resembles a football instead of being round. The doctor makes one or two incisions in the sharpest part of the cornea. This helps the cornea relax, rounding the cornea. This procedure can be performed independently or in conjunction with other laser eye procedures such as PRK, LASIK, RK, etc.
8. Are these procedures safe and effective?
The good results of these procedures are well documented, but like other procedures, these procedures alsoSide effects may occur. Patients must keep the following points in mind.
Infection and delayed healing. A small number of people develop infections after PRK or LASIK. This usually means post-operative discomfort and longer healing time.
undercorrection or overcorrection. You won’t know how well the surgery will work until the eye heals. Patients may still need to wear glasses or contact lenses. If vision is poor, a second laser surgery, called laser enhancement, may be done.
Better vision. This is rare, but some people do have worse vision after surgery. Common causes are removal of irregular tissue or excessive corneal opacity.
The cornea is too cloudy. This is part of the natural healing process after some refractive or laser eye surgery. It usually does not affect future vision and can only be detected by an eye exam. Sometimes vision may be affected, and a second surgery may be required. LASIK produces less corneal opacity than PRK. In addition, the use of mitomycin, an antitumor antibiotic, during PRK surgery can help prevent this from happening.
Degenerative vision. Occasionally, the effects of surgery wear off after a few months or years, and a second surgery may be needed to improve vision.
Halo effect. Halos may appear in dim lighting, making it difficult to drive at night or see clearly. As the pupil dilates, the untreated area outside the cornea produces a second image. This can happen after LASIK or PRK. Doctors may use laser optic zone or wavefront technology to produce a three-dimensional image of the eye to allow for more precise procedures and less chance of halos.
The flap is damaged or lost. LASIK surgery leaves a hinged flap in the center of the cornea. The tablet may need to be repositioned during the first few days after surgery or after severe direct damage to the eye.
Image source: Zhanku Hailuo
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