Refractive eye surgery is a type of eye surgery that is used to rectify refractive errors of the eye and decrease dependency on corrective lenses such as eyeglasses and contact lenses. Successful refractive procedures can reduce myopia or nearsightedness, hyperopia or farsightedness, and astigmatism or elongated corneas. A number of different procedures exist for refractive eye surgery depending upon the type and severity of the refractive error.

There are four main types of refractive eye surgery procedures: flap and photoablation procedures; corneal incision procedures; thermal procedures; and implants. Currently, the most common refractive eye surgeries involve the use of lasers to reshape the cornea.

Flap procedures involve cutting a small flap in the cornea so that the tissue underneath can be reshaped to correct the refractive error. LASIK, short for Laser Assisted In-Situ Keratomileusis, is the most popular refractive surgery and is used to correct myopia, hyperopia, and astigmatism. The LASIK procedure involves using a microkeratome or IntraLase to cut a flap into the stroma, moving the flap out of the way, removing excess corneal tissue with an excimer laser, then replacing and smoothing out the flap. LASEK is best suited for individuals with thin or flat corneas. The LASEK procedure uses a small trephine blade to cut into the shallow epithelium, after which the eye is bathed in a mild alcohol solution to soften the edges of the epithelium. The flap is gently moved out of the way so that an excimer laser can remove excess corneal tissue, after which the flap is replaced and smoothed out. Epi-LASIK, like LASEK, involves a shallow cut into the epithelium, but makes use of epikeratome to create a thin epithelium sheet for removal instead of the harsher blade and alcohol.

Photoablation, the second stage in flap procedures, makes use of ultraviolet radiation to remove excess corneal tissue. PRK, or photorefractive keratectomy, was the original laser eye surgery procedure. PRK involves numbing the eye with local anesthetic eye drops, and reshaping the cornea by destroying miniscule amounts of tissue from the surface of the eye. The laser used, an excimer laser, is a computer-controlled ultraviolet beam of light. It burns cool so as not to heat up and damage the surrounding eye tissue.

Corneal incision procedures such as radial keratotomy and arcuate keratotomy use miniscule incisions in the cornea to alter its surface and correct refractive errors. Radial keratotomy, or RK, uses a diamond tipped knife to make a number of spoke-shaped incisions in the cornea. The result of the incisions is that the cornea flattens out, minimizing the effects of myopia. Arcuate keratotomy, or AK, is very similar to RK. The diamond knife is used to cut incisions that are parallel to the edge of the cornea, as opposed to the spoke-shaped incisions of the RK procedure. These procedures have been much less common with the emergence of laser-assisted refractive eye surgeries.

Thermal procedures use heat to correct temporarily hyperopic refractive errors, or farsightedness. The thermal keratoplasty procedure involves putting a ring of 8 or 16 small burns on the eye immediately surrounding the pupil. The application of the heat increases the slope of the cornea, making it steeper, through thermal contractions. There are two main types of thermal keratoplasty. Laser Thermal Keratoplasty, or LTK, is a no-touch procedure that uses a holmium laser. Conductive Keratoplasty, or CK, uses a high-frequency electric probe.

The final type of refractive eye surgery involves the use of implants. Implantable contact lenses, or ICL, can be used to correct severe levels of myopia, hyperopia, and astigmatism. The implants are actually tiny contact lenses that are inserted through a small incision in the side of the cornea. Implants are seated so they sit immediately in front of the eye's natural lens just behind the cornea. ICL works in conjunction with the eye's natural lens to refocus light on the retina and produce a crystal clear image.

Each of these procedures has its advantages and disadvantages, and not all individuals are suitable candidates for refractive eye surgery. Individuals who are interested in learning more about surgical options should contact their ophthalmologist for more information about these procedures, as well as inquire about other new cutting-edge procedures. Since ophthalmologic surgery is constantly growing and changing with emergence of new technologies and methods, there are always new techniques in development. As new equipment is developed and methods refined that can improve the success and minimize the side effects of refractive eye surgery, new procedures will emerge to replace outdated techniques.

Refractive surgery is a general term referring to the collection of many different surgical procedures, all with the key intent to fix the refractive error of the eye. Refractive surgery is the preferred treatment for rectifying a variety of vision impairments. Its popularity is owing to the fact that it produces efficacious and predictable vision improvement without any major side effects.

Essentially speaking, refractive surgery is any eye surgery employed to improve visual acuity and decrease dependency on glasses or contact lenses. The refractive surgery field encompasses operative procedures for all types of refractive errors, be it myopia, hypermetropia, astigmatism or presbyopia. The most common procedure is to use lasers to reshape the corneal tissue.

Laser Assisted In-Situ Keratomileusis (LASIK) is the most commonly performed refractive surgery procedure. Especially recommended for treating nearsightedness, it consists of cutting a flap in the cornea in order to carve the tissue underneath and give it the desired shape. The eye surgeon may either use a microkeratome (a precision surgical instrument) or a laser to cut a flap of the corneal tissue. Then onwards, the underneath tissue is reshaped with the aid of the excimer laser (a high-precision ultraviolet chemical laser).

Other refractive surgery procedures include Laser Assisted Sub-Epithelium Keratomileusis (LASEK), EPI-LASIK, Photorefractive keratectomy (PRK), Radial keratotomy (RK) and arcuate keratotomy (AK), among others. Cataract extraction and intraocular lens implants may also be considered as types of refractive surgeries, since the key intent is to extract the lens with a refractive error and replace it with a new lens that provides clear and improved vision.

As of now, LASIK is a clear winner among the available eye corrective surgical procedures. All the above listed refractive surgery procedures have potential complications. However, LASIK has a minimal complication rate of a mere 5%. With the technology in hand and with proper pre-operative examination, your laser eye surgery would go as smooth as a walk in the park.

Photorefractive keratectomy (PRK) is a laser eye surgery procedure that is carried out with the key intent to correct a patient's vision. PRK permanently changes the shape of the frontal corneal tissue using an excimer laser, which is a high-precision ultraviolet chemical laser. The outer layer of the cornea (epithelium) is removed, and then a small amount of the corneal tissue is burnt off using the laser. Such an ablation renders the desired shape to the cornea and allows for optimal refraction.

PRK is a technologically advanced surgical procedure. For instance, a computer system tracks the eye position around 4,000 times per second, redirecting laser pulses for precise ablation. As mentioned above, the epithelium is removed prior to ablation. This does not hamper the patient's vision, since the epithelium is a soft and regenerating layer, which is capable of completely replacing itself within a matter of days. However, the deeper layers, once burnt off, will remain that way because they possess limited regenerative capability. This theory is the cornerstone of the Photorefractive keratectomy surgical procedure.

PRK differs from LASIK in a way that the epithelium is removed in PRK and allowed to regenerate. On the other hand, LASIK does not involve epithelium removal. Instead it consists of cutting a flap in the cornea in order to make the desired incisions. Compared to LASIK, a patient who has undergone PRK experiences more pain and recovery is slow. However, both procedures are similar in the respect that they make use of a laser.

Photorefractive keratectomy is a viable procedure, but it does have possible complications. Apart from slow recovery and pain, the patient may experience glares and halos. As in any refractive surgery, there is a possibility of over- or under-correction. Eye surgeons typically perform PRK on one eye at a time, in order to gauge the results of the procedure and ensure its efficacy.

In a majority of cases, PRK has proven to be a safe and efficacious procedure to correct myopia. However, since the procedure is irreversible, it is recommended that the patient consults an eye doctor instead of jumping on a conclusion.