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Please improve this article or discuss the issue on the talk page. | Refractive eye surgery is any eye surgery used to improve the refractive state of the eye and decrease dependency on glasses or contact lenses. This can include various methods of surgical remodelling of the cornea or cataract surgery. The most common methods today use excimer lasers to reshape curvature of the cornea. Successful refractive eye surgery can help to reduce common vision disorders such as myopia, hyperopia and astigmatism. Image File history File links Gnome-globe. ...
Eye surgery in the middle ages. ...
For other uses, see Eye (disambiguation). ...
A pair of modern glasses Glasses, also called eyeglasses or spectacles, are frames, bearing lenses worn in front of the eyes normally for vision correction, eye protection, or for protection from UV rays. ...
A soft contact lens A contact lens (also known as contact, for short) is a corrective or cosmetic lens placed on the cornea of the eye atop the iris. ...
An excimer laser is a form of ultraviolet chemical laser which is commonly used in eye surgery and semiconductor manufacturing. ...
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber, providing most of an eyes optical power [1]. Together with the lens, the cornea refracts light and, as a result, helps the eye to focus. ...
Normal vision. ...
Hyperopia, also known as hypermetropia or colloquially as farsightedness or longsightedness, is a defect of vision caused by an imperfection in the eye (often when the eyeball is too short or when the lens cannot become round enough), causing inability to focus on near objects, and in extreme cases causing...
Astigmatism is an affliction of the eye, where vision is blurred by an irregularly shaped cornea. ...
According to surveys of members of the American Society of Cataract and Refractive Surgery, approximately 948,266 refractive surgery procedures were performed in the United States during 2004 and 928,737 in 2005.[1]
History The first experimental studies about refractive surgery were developed by Lendeer Jans Lans, an ophtalmology teacher in Holland, 1896 where he published a theoric work proposing penetrant corneal cuts to correct astigmatism. In 1930 the japanese ophtalmologyst Sato made the fist practical attempt to perform such surgery in military pilots. He practiced radial cuts in the cornea to correct effects up to 6 dyoptries, but this procedure was soon rejected by the medical community because the high rate of corneal degeneration. In 1963, in the Barraquer ophtalmologic clinic ( Bogotá,Colombia) Ignacio Barraquer developed the first proficient technique to refractive surgery, called keratomileusis (from the greek Kerato: cornea and Mileusis: to sculpt) meaning corneal reshaping. Keratomileusis allowed to correct not only myopia but also hyperopia. The early surgeries were made removing a corneal layer, freezing it so it could be manually sculpted in the required shape and finally reimplant the layer (Keratomileusis with freezing). In 1986 Dr Swinger improved the surgery (keratomileusis without freezing) but it was still a slightly imprecise technique. In 1958 Arthur Schawlow and Townes, from Bell laboratories published their theory of stimuled emission of shorter length waves, included light, which gave place to the development of Laser. In 1975 experiments with laser using a mix of argon and fluor ended with the invention of the Excimer. This Laser was used with industrial purposes. In 1980, R. Srinivasan, a scientist of IBM who was using the Excimer to make microscopic circuits in microchips for informatic quipments, discovered that the Excimer could be used also to cut organic tissues with high accuracy without significant thermal damage. In 1983 Stephen Trokel, scientist of Columbia University in collaboration with Srinivasan performed the Photorefractive Keratectomy (PRK) or keratomileusis in situ (without separation of corneal layer) wich was more technically exact, but the patients reported it to be very umcomfortable. Also a delay in the healing was observed. The first PRK was performed in Germany. In 1991 the Creta University and the Vardinoyannion Eye developed the Lasik that worked with the same principles, but removing first a lens shaped piece of the outer layer of the cornea, sculpting the inner layer and relocating the piece to cover, which allows a better healing, without discomfort. Holland is a region in the central-western part of the Netherlands with a population of 6. ...
Year 1896 (MDCCCXCVI) was a leap year starting on Wednesday (link will display calendar). ...
Astigmatism is an affliction of the eye, where vision is blurred by an irregularly shaped cornea. ...
Year 1930 (MCMXXX) was a common year starting on Wednesday (link will display 1930 calendar) of the Gregorian calendar. ...
SatÅ (ä½è—¤, characters for assistance and wisteria) is the most common Japanese surname. ...
Year 1963 (MCMLXIII) was a common year starting on Tuesday (link will display full calendar) of the Gregorian calendar. ...
Motto: Bogotá, 2600 metros más cerca de las estrellas Bogotá, 2600 meters closer to the stars Localities (localidades) of Bogotá Country Department Foundation August 6, 1538 Government - Mayor Luis Eduardo Garzón, PDA Area - City 1,587 km² (612. ...
Ignacio Barraquer (March 25, 1884 - May 13, 1965) was a Spanish ophthalmologist known for his contributions to the advancement of cataract surgery. ...
Keratomileusis is the surgical improvement of the refractive state of the cornea performed by lifting up the front surface of the eye by forming a thin hinged flap under which the shape of the cornea is changed by using an excimer laser or other surgical device. ...
Arthur Leonard Schawlow (May 5, 1921–April 28, 1999) was an American physicist. ...
Look up bell, Bell in Wiktionary, the free dictionary. ...
Experiment with a laser (US Military) In physics, a laser is a device that emits light through a specific mechanism for which the term laser is an acronym: Light Amplification by Stimulated Emission of Radiation. ...
General Name, Symbol, Number argon, Ar, 18 Chemical series noble gases Group, Period, Block 18, 3, p Appearance colorless Standard atomic weight 39. ...
Fluor Corporation NYSE: FLR,is one of the worlds largest publicly owned engineering, procurement and construction organizations, with maintenance services in addition. ...
For other uses, see IBM (disambiguation) and Big Blue. ...
Microchip can refer to: Microchip (or simply chip) is used rather loosely in electronics. ...
Columbia University is a private research university in the United States and a member of the prestigious Ivy League. ...
Crete (Greek: ΚÏήτη KrÃti; Turkish: Girit) is the largest of the Greek islands and the fifth largest in the Mediterranean Sea. ...
LASIK is the acronym for Laser-Assisted in Situ Keratomileusis, a type of refractive laser eye surgery performed by ophthalmologists for correcting myopia, hyperopia, and astigmatism. ...
Techniques
Flap procedures Consists in cutting a flap in the cornea in order to access the tissue underneath. - Automated lamellar keratoplasty (ALK): The surgeon uses an instrument called a microkeratome to cut a thin flap of the corneal tissue. The flap is lifted like a hinged door, targeted tissue is removed from the corneal stroma, again with the microkeratome, and then the flap is replaced.
- Laser Assisted In-Situ Keratomileusis (LASIK) is the most commonly performed refractive surgery procedure as of 2007. Surface treatment ablation has gained a renewed interest in recent years as evidence of good outcomes have been shown. LASIK is performed for a wide range of nearsightedness. The surgeon uses a microkeratome to cut a flap of the corneal tissue (usually with about 160 micron in thickness). The flap is lifted like a hinged door, but in contrast to ALK, the targeted tissue is removed from the corneal stroma with an excimer laser. The flap is subsequently replaced. A major improvement of this technique is the use of a femtosecond Laser to create the flap. It provides more precision, and therefore less side effects.
- Laser Assisted Sub-Epithelium Keratomileusis (LASEK) is a procedure that changes the shape of the cornea using an excimer laser to ablate the tissue from the corneal stroma, under the corneal epithelium, which is kept almost intact to act as a natural bandage.
- EPI-LASIK is a new technique similar to LASEK, that uses an epi-keratome (rather than a trephine blade and alcohol) to remove the top layer of the cornea.
Automated Lamellar Keratoplasty, commonly abbreviated to ALK uses a device called a microkeratome to separate a thin layer of the cornea and create a flap. ...
A microkeratome is a precision surgical instrument with an oscillating blade designed for creating the corneal flap in LASIK or ALK surgery. ...
LASIK is the acronym for Laser-Assisted in Situ Keratomileusis, a type of refractive laser eye surgery performed by ophthalmologists for correcting myopia, hyperopia, and astigmatism. ...
A microkeratome is a precision surgical instrument with an oscillating blade designed for creating the corneal flap in LASIK or ALK surgery. ...
This article or section should be merged with Photorefractive keratectomy LASEK, an acronym for Laser-Assisted Sub-Epithelial Keratectomy, is an eye surgery procedure intended to reduce a persons dependency on glasses or contact lenses. ...
An excimer laser is a form of ultraviolet chemical laser which is commonly used in eye surgery and semiconductor manufacturing. ...
Bandages are also used in martial arts to prevent dislocated joints. ...
Epi-LASIK is a refractive surgery technique invented by Dr Ioannis Pallikaris (Crete, Greece). ...
Photoablation procedures - Photorefractive keratectomy (PRK) is an outpatient procedure generally performed with local anesthetic eye drops (as LASIK) . It is a type of refractive surgery which reshapes the cornea by destroying microscopic amounts of tissue from corneal stroma, using the computer-controlled beam of light (an excimer laser). The difference from LASIK is that all the epithelium is removed (and a bandage contact lens must be used). Recovery time is much longer with PRK than with LASIK, though the final outcome (after 3 months) is about the same (very good). More recently, customized ablation have been performed either with LASIK or PRK.
// Photorefractive keratectomy (PRK) and Laser-Assisted Sub-Epithelial Keratectomy (LASEK) are laser eye surgery procedures intended to correct a persons vision and reduce their dependency on glasses or contact lenses. ...
Anesthesia (AE), also anaesthesia (BE), is the process of blocking the perception of pain and other sensations. ...
An excimer laser is a form of ultraviolet chemical laser which is commonly used in eye surgery and semiconductor manufacturing. ...
Corneal incision procedures - Radial keratotomy (RK) uses spoke-shaped incisions (usually made with a diamond knife) to alter the shape of the cornea and reduce myopia or astigmatism; this technique has now been largely replaced by the other methods (that use excimer laser).
- Arcuate keratotomy (AK) is similar to radial keratotomy, but the incisions on the cornea are done at the periphery of the cornea. Arcuate keratotomy is used to correct astigmatism. Although most incisional procedures are replaced nowadays by Lasik, AK is still used in some special cases (correction of residual astigmatism after a keratoplasty procedure or during cataract surgery).
Radial keratotomy (RK) is a refractive surgical procedure to correct myopia. ...
Other procedures - Thermal keratoplasty is used to correct hyperopia by putting a ring of 8 or 16 small burns surrounding the pupil, and steepen the cornea with a ring of collagen constriction. It can also be used to treat selected types of astigmatism.
- Laser thermal keratoplasty (LTK) is a no-touch thermal keratoplasty performed with a Holmium laser, while conductive keratoplasty (CK) is thermal keratoplasty performed with a high-frequency electric probe. Thermal keratoplasty can also be used to improve presbyopia or reading vision after age 40.
- Intra-Stromal corneal rings (Intacs) are approved by FDA for treatment of low degrees of myopia.
- Lens implantation inside the eye can also be used to change refractive errors.
Hyperopia, also known as hypermetropia or colloquially as farsightedness or longsightedness, is a defect of vision caused by an imperfection in the eye (often when the eyeball is too short or when the lens cannot become round enough), causing inability to focus on near objects, and in extreme cases causing...
General Name, Symbol, Number holmium, Ho, 67 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 164. ...
Conductive keratoplasty (CK) is a type of refractive surgery that uses radio waves to adjust the contour of the cornea by shrinking the corneal collagen around it. ...
Expectations The Council for Refractive Surgery Quality Assurance, an independent, nonprofit, patient/consumer health organization that provides information about refractive surgery and certifies LASIK surgeons, considers surgeons with results of 90% of patients achieving 20/40 or better and 50% achieving 20/20 or better with limited complication rates as meeting national norms.[2] The Council for Refractive Surgery Quality Assurance (CRSQA) is an independent, nonprofit, patient/consumer health organization that provides detailed information about LASIK and certifies refractive surgery doctors based upon patient outcomes. ...
Many people with myopia are able to read comfortably without eyeglasses. Myopes considering refractive surgery are advised that this may be an advantage after the age of 40 when the eyes become presbyopic and lose their ability to accommodate or change focus. Presbyopia (Greek word presbyteros (Ï€ÏεσβÏτεÏος), meaning elder) is the eyes diminished ability to focus that occurs with aging. ...
Light from a single point of a distant object and light from a single point of a near object being brought to a focus by changing the curvature of the lens. ...
Risks While refractive surgery is becoming more affordable and safe, it may not be recommended for everybody. Patients that have medical conditions such as glaucoma or diabetes, uncontrolled vascular disease, autoimmune disease, pregnant women or people with certain eye diseases involving the cornea or retina, are not good candidates for refractive surgery. Keratoconus, a progressive thinning of the cornea, is a common corneal disorder. It is believed that additional thinning of the cornea via refractive surgery may contribute to advancement of the disease [3] , that may lead to the need for a corneal transplant. Therefore, keratoconus is a contraindication to refractive surgery. Corneal topography, paquimetry and, more recently, Pentacam exams are used to screen for abnormal corneas. Furthermore, some people's eye shape may not permit effective refractive surgery without removing excessive amounts of corneal tissue. Those considering laser eye surgery should have a full eye examination. This article is about the disease that features high blood sugar. ...
This article or section does not cite its references or sources. ...
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber, providing most of an eyes optical power [1]. Together with the lens, the cornea refracts light and, as a result, helps the eye to focus. ...
Human eye cross-sectional view. ...
Keratoconus (from Greek: kerato- horn, cornea; and konos cone), is a degenerative non-inflammatory disorder of the eye in which structural changes within the cornea cause it to thin and change to a more conical shape than its normal gradual curve. ...
Cornea Transplant A cornea transplant, also known as a corneal graft or penetrating keratoplasty, is a surgical procedure where a damaged or diseased cornea is replaced by a donor. ...
Traditional Snellen chart used for visual acuity testing. ...
Traditional Snellen chart used for visual acuity testing. ...
References
See also This article or section does not cite its references or sources. ...
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