PRK or ASA – advanced surface ablation, treats refractive error by removing tissue from the surface of the cornea. First, your eye is completely numbed using "eye drop" anesthesia and an instrument is placed between the eyelids to prevent blinking. Then the surgeon gently removes the epithelium, a thin layer of protective cells covering the cornea. The patient is told to look directly at a target light during the procedure. In less than a minute or two, the laser removes the proper amount of tissue while it reshapes the surface of the cornea. By altering the shape or placement of the laser beam, the cornea is made flatter to treat nearsightedness, steeper treat farsightedness, and/or astigmatism.
After PRK, patients may experience mild, hazy vision for one to five days until the epithelium heals and covers the treated area. Eye drops, pain medication, and a protective contact lens are effective in minimizing any post-operative discomfort. Final visual results may be fully realized as the surface heals in accordance to each individual's healing tendencies. PRK is most often used to treat low to moderate amounts of nearsightedness, farsightedness and astigmatism.
ICL (Implantable Contact Lens)
The Implantable Contact Lens (ICL) is a procedure that can improve vision and reduce or eliminate dependence on eyeglasses or contact lenses.
This minimally invasive surgical procedure has already helped thousands of patients who have moderate to severe myopia, or nearsightedness.
Similar to a contact lens, it is manufactured to the specifications of the patient's visional needs and works with their natural eye to focus. It is implanted inside the eye, just behind the iris (the colored part of the eye). This placement ensures that the lens remains virtually undetectable by the patient or an observer. The lens does not move once it is in place and it cannot be felt by the patient.
An ICL implantation does not remove or thin the cornea (or any other part of the eye) to achieve its optical effect. Rather, a biocompatible synthetic lens (much the same size and shape as a soft contact) is surgically inserted under high magnification just behind the pupil and on top of the natural lens. This synthetic lens is designed for the patient's specific optical prescription.
The material used in the ICL is composed of pure collagen and a hydrophilic copolymer with a UV absorbent chromophore. These materials are biocompatible with the body, which means they are gentle on the eyes, very stable and do not cause any reaction inside the eye.
The ICL can be undone or removed and even replaced with a new power ICL if there is ever a change in prescription years later. The ICL can also be used in cases of thin corneas and high, even extreme nearsightedness where LASIK would remove too much corneal tissue to be compatible with long-term structural integrity of the eye.
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Intacs™ is a non-laser procedure with FDA approval for use in patients with low amounts of myopia. The commercially available segments in the U.S. are intended to correct low amounts of nearsightedness but not astigmatism. The procedure involves the placement of two plastic segments within the non-seeing periphery of the cornea. These segments flatten the central cornea without removing tissue to better focus light. The segments are made of the same biocompatible material found in cataract lens implants (intraocular lenses). Intacs can be replaced with different-size implants or removed all together.
In July 2004 the FDA granted Intacs a Humanitarian Device Exemption to allow corrections of Keratoconus because only a few options, such as corneal transplants, are available for keratoconus.
Keratoconus is a disease that creates a thinning of the cornea or the clear front surface of the eye. Normal outward pressure within the eye causes the cornea to progressively bulge into a cone-like shape. The change in the cornea's shape can have a dramatic impact on one's vision. In more severe cases, normal everyday activities such as driving and reading can be difficult to perform. Although keratoconus rarely results in total blindness, 20% of all patients will at some time undergo a corneal transplant, according to medical experts.
Keratoconus is estimated to affect one in 2,000 people. It is normally treated with rigid contact lenses that reshape and flatten the pronounced bulge in the cornea while improving one's vision. A proper contact lens fit is crucial as poorly prescribed or outdated contact lenses can lead to additional complications like corneal abrasions, scarring, and infection.
Intacs can be very effective at changing the cornea and flattening the cone caused by keratoconus.
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