Intacs Corneal Ring Segments
Corneal ring segments, also called intrastromal corneal ring segments (ICRS), are implantable devices that can change the shape of the front of the eye and correct mild to moderate amounts of nearsightedness and vision problems caused by keratoconus.
Intacs (Addition Technology, Inc., Des Planes, Ill.) is the most popular brand of FDA-approved corneal ring segments used in the United States.
Intacs surgery has certain advantages over LASIK eye surgery and other laser vision correction procedures for the correction of myopia, such as PRK, Epi-LASIK and LASEK. Specifically, the Intacs procedure does not remove any tissue from the central cornea, so there is essentially no risk of inducing higher-order aberrations or causing corneal thinning that could lead to ectasia.
Also, the Intacs procedure is reversible: the corneal ring segments can be removed if you are dissatisfied with the surgical outcome or your vision changes months or years after implantation of the corneal rings.
But the Intacs procedure can correct only limited amounts of myopia (up to -3.00 diopters) and cannot correct farsightedness or significant astigmatism.
Due to advances in wavefront-guided LASIK and the safety and effectiveness of modern laser vision correction for the treatment of myopia, most Intacs procedures performed today are to treat keratoconus rather than correct common nearsightedness.
The Intacs Procedure
Like LASIK, Intacs corneal ring segment surgery is performed on an outpatient basis and requires only local anesthesia (numbing eye drops). If you desire, your eye surgeon can also give you a mild oral sedative to relax you prior to the surgery.
The procedure only takes about 15 minutes per eye, but plan to be at the surgery center for an hour or two.
Basically, the steps of the Intacs procedure are:
- A single small incision is made in the surface of the cornea. The incision is placed in the mid-periphery of the cornea, outside the pupil zone.
- A surgical instrument is placed on your eye and creates two small semicircular channels within the cornea. The channels are created well under the corneal surface, at a depth equal to about two-thirds the total corneal thickness.
- The Intacs corneal ring segments are inserted into the two channels, and the small incision in the cornea is closed.
In a new version of the procedure, the corneal channels that hold the corneal inserts are created with a femtosecond laser instead of a bladed instrument.
After the procedure, the corneal ring segments are virtually invisible and cannot be felt. The implants correct myopia by increasing the curvature of the peripheral cornea and reducing the curvature of the central cornea.
The Intacs corneal inserts are made of a clear and biocompatible plastic material, and they can be left in the eye indefinitely.
Safety and Effectiveness of Intacs Surgery
According to Addition Technology, Inc., the safety and effectiveness of Intacs corneal implants are supported by more than 11 years of clinical studies.
Data from FDA clinical trials reveal that more than 97 percent of patients who undergo Intacs corneal ring segment surgery are able to meet vision requirements for driving without glasses or contact lenses (usually 20/40 or better), and more than 50 percent achieve uncorrected visual acuity after surgery that is better than 20/20, the company says.
Risks of Corneal Ring Segment Surgery
As with any vision correction surgery, there are some Intacs surgery risks, including risks of infection and reduced vision.
Some patients experience visual symptoms, including glare, halos, blurry or fluctuating vision and night vision problems. Usually, these symptoms are temporary and resolve over time without further treatment.
Follow-up visits are required after surgery to monitor the healing process and evaluate your vision with the corneal ring inserts. Even after a successful procedure, you may still need glasses for certain visual tasks.
If your vision is not acceptable after Intacs surgery, in some cases removing the corneal ring segments and replacing them with implants of a different thickness will improve vision.
Intacs also can be permanently removed if desired. In cases where Intacs were removed in U.S. clinical studies, all patients were able to achieve 20/20 vision or better with corrective lenses, according to Addition Technology, Inc.
Are You a Good Candidate for Intacs Corneal Implants?
To be a good candidate for Intacs intrastromal corneal ring segment surgery, you should:
- Have between -1.00 and -3.00 diopters (D) of myopia
- Have no more than 1.00 D of astigmatism
- Be at least 21 years of age
- Have had stable vision for the past year or longer
- Have healthy eyes that are free from disease or past injury
The only way to know for sure if you are a good candidate for the procedure, however, is to schedule a comprehensive eye exam and consultation with an eye surgeon who specializes in Intacs corneal implant surgery. If you suffer from keratoconus, the eye surgeon can determine whether Intacs are a viable keratoconus treatment for you.
Intacs Surgery Cost
Generally, the cost of Intacs corneal ring segment surgery is comparable with or a bit higher than the cost of LASIK surgery and other laser vision correction procedures.
Though price should not be the primary factor in choosing an eye doctor, it is a good idea to get quotes for the cost of Intacs surgery from at least two refractive surgeons in your area.
Be sure to ask what services and follow-up care are covered in the quote you receive for Intacs surgery cost. Some doctors quote global fees that cover all pre-operative and post-operative care as well as the surgery itself, whereas other doctors present "a la carte" pricing, where each service is priced separately. Make sure you understand exactly what you will receive for the price quoted.
Intacs and other intrastromal corneal ring surgery for the correction of keratoconus usually are covered by major medical insurance. Ask your eye surgeon and health insurance provider for details.
But Intacs surgery for the treatment of common myopia is considered an elective vision correction procedure. As such, costs associated with the surgery typically are "out-of-pocket" expenses that are not covered by vision insurance or health insurance.
If you have a vision discount plan, however, a percentage of your surgical fee may be waived. Ask your vision insurance provider for details concerning your coverage prior to Intacs vision correction surgery.
Many eye surgeons offer financing plans for Intacs surgery and other elective vision correction procedures to enable you to pay for the procedure over a period of time to make it more affordable.
Note: This information is for general education purposes only. It is not to be used as a substitute for medical advice from your eye doctor or refractive surgeon.