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Intacs are a medical device approved by the FDA for the correction of 1.00 to 3.00 diopters of myopia (nearsighted, shortsighted) and virtually no astigmatism in normal healthy corneas. Intacs are clear small semicircular plastic rings of various thickness that are inserted within the cornea at its outer edges. Insertion of these rings flatten the central area of the cornea and correct myopic refractive error. A major advantage of Intacs is that no tissue is removed and there is no ablation or incision across the visual axis. To insert Intacs, a single semicircular incision is made in the periphery of the cornea about 2/3rds deep into which the Intacs are placed by a doctor. The incision can be made with a mechanical separator, or with an Intralase femtosecond laser. Generally, stitches are not necessary. Intacs surgery is not truly reversible because of the incision, but the Intacs can be completely removed or exchanged for a different size. Intacs inserts cannot be felt by the patient and are no more visible than a contact lens. After insertion and healing, Intacs require no maintenance. In the myopic eye, the curve of the cornea is too steep. Light rays are bent too much and focus in front of the retina. Excimer laser assisted refractive surgery like conventional or custom wavefront Lasik, Bladeless Lasik, PRK, LASEK, and Epi-Lasik all change the steepness of the myopic eye by permanently removing tissue in the center of the cornea to make the cornea more flat. Intacs flatten the cornea by insertion into the periphery of the cornea, stretching the center of the cornea and causing a flattening effect. Intacs are a viable alternative to Lasik and similar excimer laser techniques for select patients, but probably because of their inability to treat moderate and high myopia, astigmatism, or hyperopia (farsighted, longsighted), Intacs never became widely accepted. However, Intacs inserts are the only refractive surgery procedure that adds structural integrity to the cornea. This unique attribute made Intacs an ideal treatment for keratoconus. Keratoconus is a disorder that involves a thinning and weakening of the central cornea. The normally round shape of the cornea becomes distorted. A cone-like bulge develops, resulting in significant visual impairment. The placement of Intacs inserts remodels and reinforces the cornea, eliminating some or all of the irregularities caused by keratoconus. Because of the abnormal nature of a cornea with keratoconus, Intacs have been able to effect significantly more refractive change than what normally occurs in healthy corneas. Follow-up visits will be required to monitor the healing process and to evaluate the visual benefits of the procedure. Even after a successful Intacs procedure for keratoconus, glasses or contacts may be required, however Intacs have been shown to improve vision and reduce or stop the progression of keratoconus, thereby saving the patient from needing a corneal transplant. Additionally, by making the cornea more regular, patients who had become contact lens intolerant may be able to again wear contacts after Intacs. Intacs have been approved for the treatment of keratoconus by the FDA under a Humanitarian Device Exemption (HDE) Humanitarian Use Devices (HUDs) are medical devices specially designated by the FDA for use in the treatment of fewer than 4000 patients per year with rare medical conditions. Intacs inserts are contraindicated for patients with collagen vacular, autoimmune or immunodeficiency diseases, who are pregnant or nursing, who have ocular disease, or are taking one of more of the following medications: isotretinoin (Accutane1), amiodarone (Cordarone2), sumatriptan (Imitrex3). Intacs are manufactured by Addition Technology. Some images courtesy Addition Technology Consider and Choose With Confidence Last updated d Saturday, August 18, 2012 |
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