Intacs


Intacs are available at the following centres:

BMI Mount Alvernia Hospital
Manchester Royal Eye Hospital
Sheffield Royal Hallamshire Hospital


A NICE and FDA approved option for keratoconus delaying the need and sometimes avoiding the need for corneal transplant.

Intacs corneal inserts or implants are a minimally invasive surgical option used primarily for the treatment of keratoconus.

Originally FDA-approved in 1999 for the surgical treatment of mild myopia (-1.0D to -3.0D), Intacs are two tiny, clear crescent-shaped pieces of a plastic polymer that are inserted into the cornea to reshape the front surface of the eye.

The FDA in July 2004 granted Intacs a Humanitarian Device Exemption for use in the treatment of keratoconus largely because of Intacs’ safety record and because only a few treatment options, such as corneal transplants, were available for keratoconus.

The approval allows Intacs to be marketed for reduction or elimination of myopia and astigmatism in keratoconus patients where functional vision is no longer obtained with contact lenses or glasses.

In early January 2006, the FDA formally acknowledged that Intacs implants are therapeutic devices that can be described in company literature as corneal implants, rather than prescription inserts.

How Do Intacs Work?

Person inside tent.Person inside tent, pushing on the sides.For treating nearsightedness, Intacs correct vision by flattening the cornea to refocus light rays and improve vision. For keratoconus, Intacs work by flattening the steep part of the cornea or cone to reduce vision distortions.

Intacs are made of the same biocompatible material found in intraocular lenses used for cataract surgery, so there is little or no risk of adverse effects from the material.

What Makes Corneal Segments unique?

Lasers reshape your cornea by permanently removing tissue from the central optic zone. This tissue cannot be added back. When laser patients need an adjustment to their vision, additional tissue must be removed. If your prescription changes, more procedures and more tissue removal may be needed.

But no tissue is removed during an Intacs corneal implant procedure. Intacs corneal implants change the curvature of your eye by adding ultra-thin ring segments, rather than removing tissue.

If an adjustment is needed, Intacs corneal implants may be replaceable with a different prescription. They can be completely removed if necessary, returning your eyes to much like their preoperative condition. Intacs corneal implants maintain your options like no other vision correction procedure.

Surgery FAQs
What is the procedure?
The procedure takes about 15 minutes and is done on an outpatient basis, but you will need someone to drive you home after surgery. Before surgery, your surgeon places anesthetizing drops in your eye and may give you a mild oral sedative.

 

During the procedure, your surgeon uses a femtosecond laser to create a channel between layers of the cornea, outside of the central optical zone. Your surgeon then chooses the appropriate ring thickness. A thicker ring in Intacs means more flattening of the cornea, which increases the level of vision correction achieved. After one or two crescent-shaped Intacs are inserted into the tunnel, the procedure is over.

 

After Intacs Surgery
You’ll probably rest for a while, then go home (have someone else drive you). Most people have sharper vision the first day after surgery, but you may need a couple of days of relaxation to promote healing. You won’t feel the ring segments, because they are beneath the cornea’s nerve endings. Other people can’t see them unless they look very closely into your eyes.

The ring segments flatten your cornea similarly to the way you can flatten the top of a tent by pushing on the sides.

Results of these implants will depend on the degree of keratoconus in each individual. People with milder cases of keratoconus may not need any lenses for additional vision correction. People with moderate keratoconus may require glasses or soft contact lenses for improved vision.

For more advanced cases, rigid gas permeable contact lenses may be needed to improve vision or to delay or prevent the need for a corneal transplant.

Intacs can be very effective at changing the cornea and flattening the cone caused by keratoconus. But if you have advanced keratoconus, Intacs cannot halt the progression caused by weakening of surface eye tissue (collagen) responsible for corneal strength.

 

Results of Clinical Trials for Intacs for Keratoconus
In 58 keratoconus eyes implanted with Intacs, almost half (25) achieved 20/40 uncorrected vision or better in a study reported in the October 2005 issue of Archives of Ophthalmology. Studies also have shown that Intacs may be able to reduce vision distortions in people with keratoconus who also have developed irregular astigmatism associated with an uneven eye surface.

In another study, single-segment Intacs improved both uncorrected vision and lens corrected vision for LASIK eye surgery patients who developed keratoconus or progressive corneal thinning (ectasia) as a complication. Single-segment Intacs also were more effective than double-segment Intacs in the same study reported in the May 2006 issue of American Journal of Ophthalmology.

Among 28 people in the post-LASIK study, 37 eyes were treated with either single-segment or double-segment Intacs. Each group was matched for factors such as age. The single-segment group averaged about nine lines of uncorrected vision improvement on a standard eye chart, compared with 2.5 lines in the double-segment group.

 

Results of Clinical Trials for Intacs for Nearsightedness
A literature review of 452 patients who underwent Intacs corneal ring implantation for the correction of nearsightedness was published in the October 2001 issue of Ophthalmology.Twelve months after surgery, 97 percent of treated eyes had 20/40 vision or better, and 74 percent had 20/20 or better.

Just under 9 percent of patients requested to have their Intacs removed due to side effects such as glare, halos and night vision problems or because their vision was under- or over-corrected, and 3.8 percent required a secondary surgical procedure. There were no serious complications.

A study of the reversibility of Intacs for nearsightedness, published in the January 2001 issue of Journal of Refractive Surgery, found that 20 of the 21 eyes returned to within 1.0 diopter of their preoperative refraction, with stable vision three months after removal was performed safely and without complications.

 

Am I a Candidate for Intacs?
If you are considering Intacs surgery for keratoconus, your first step is to have a comprehensive eye exam by an ophthalmologist who specializes in the procedure. He or she will examine your eyes and perform a number of measurements to determine if the procedure is likely to improve your vision.

If you are interested in Intacs corneal ring implantation for the correction of nearsightedness, you must be at least 21 years of age and have a stable eyeglasses prescription with no more than -3.0 diopters (D) of myopia and no more than 1.0 D of astigmatism.

After examining your eyes, your eye doctor can tell you more about Intacs. The cost of the procedure varies from surgeon to surgeon, but generally Intacs cost slightly more than laser vision correction.

 

Are Intacs Inserts Right For Me?
The best way to determine if Intacs corneal implants are right for you is to consult a doctor who specializes in Intacs corneal implants, who can give you all the facts and evaluate your eyes.

 

For further patient education, please click on the INTACS Guide

 


Your LaserVision consultant surgeon can expertly guide you through the best treatments for you. Each treatment is personalised to achieve the best results.



In association with:
Sheffield Teaching Hospital NHS Foundation Trust, Greater Manchester University Hospitals NHS Foundation Trust