Hope For a Visually Debilitating Condition

The pursuit of visual correction has taken many paths over the years, some better then others. On occasion, a protocol that is intended for one use can be applied to another with results that exceed its original intentions. Such is the case with Intacs, which are corneal implants to correct visual anomalies.

Intacs are corneal implants that are surgically inserted into the matrix of the cornea to flatten the curvature of the structure. They were initially developed as a refractive technique to reduce or eliminate nearsightedness between 1 and 3 diopters. When the procedure was first performed after FDA approval in 1999, 97% of the post surgical patients were able to see 20/40 or better with 74% seeing 20/20. However, complaints of glare, poor night vision, halos, and under/overcorrection; resulted in 39% of these patients having the Intacs removed. In almost all these cases, the cornea returned to its original shape and refractive power with in 1 year.

Intacs work by flattening the corneal surface, and thus refocusing light on to the retina. The parameters of the procedure were quite limited, to 1-3 diopters of myopia, and the visual side affects were unpleasant resulting in the demise of the procedure. In addition, with the introduction of LASIK, Intacs as a refractive procedure died an early death. However, a creative surgeon realized that patients with Keratoconus would benefit from this surgery. Keratoconus is a progressive, genetic corneal condition whereby the cornea becomes steeper, thinner and distorted over time. This results in reduced vision and often visual distortion that are not fully correctable by conventional eyeglasses. Hard contact lenses are frequently worn, but discomfort can limit their wearability.

In 2004 the FDA granted Intacs a Humanitarian Device Exemption to allow its use on Keratoconic patients to flatten out the distorted cornea, and permit clearer, more stable vision many times with out the use of hard contact lenses. In 2006 the FDA formally recognized Intacs as a therapeutic device for surgical correction of Keratoconus. They are used for long term correction, but can be removed at any time should the need arise. The Intacs come in several sizes depending on need and desired results. In Keratoconus; by altering the shape of the cornea a smooth refractive surface will permit a sharper focal point of light on to the retina and thus a clearer image.

Some patients have developed eye irritation post surgically, and in a few cases abnormal blood vessel ingrowth (neovascularization) has also occurred. It also should be noted that in 5% of these cases there was no visual improvement post-surgically. Obviously the true success of this procedure will depend on the severity of the Keratoconus and degree of corneal distortion. Dr. Thierry Hufnagel of Long Island has performed many Intacs implants on Keratoconus patients, and has remarkable success. He chooses his patients very carefully in order to select those that will be best served by this surgery.