The most prevalent type of corneal implants are called Intacs, two half-rings that reshape the curvature of the cornea from within to enhance the natural shape of the eye and correct flawed vision. These corneal implants are an alternative to LASIK for people with mild to moderate nearsightedness and limited astigmatism.
Intacs achieve a similar result to the Verisyse lens, but the means to this end is different. Intac implants correct nearsightedness by flattening out the cornea rather than refocusing the light. During surgery, the doctor inserts the corneal ring into a small channel created between layers of the cornea. These channels were once made by hand, but now, using precise IntraLASIK technology, the channels are created to exact specifications using a laser. The thickness of the ring determines the amount of correction, with a thinner ring having less impact on the cornea’s shape and thus providing a lesser correction. The entire procedure usually takes about 15 minutes.
The rings are placed in the cornea beneath the nerve endings, so they will not cause any irritation or be noticeable in the eye. They are also nearly invisible, and because they are permanently in place within the cornea, they never require maintenance and will not dry out.
Intacs can also be removed or reshaped if necessary, and patients have the option of replacing them at a later date should their prescription change. Because the procedure involves no permanent change to the cornea, LASIK also remains an option both before and after removal.
The LASIK procedure is the right answer for most patients who are considering refractive surgery to improve their vision. However, in patients with higher degrees of nearsightedness or farsightedness, the cornea may be too thin to allow full refractive correction.
In these cases, surgical implants may be the best alternative. These special devices are placed in the eyes to improve their focusing ability.