Experts believe there are several causes and contributing factors to keratoconus, such as genetics, allergies and even vigorous eye rubbing. Experts have also noted a link between keratoconus and Down syndrome. International EyeCare Laser & Lifestyle Center treats cases of keratoconus in Houston and the surrounding area.
The first sign of keratoconus is typically blurred vision and nearsightedness. Individuals who have keratoconus may notice that glasses do not correct the blurred vision. They may also experience sensitivity to light, glares, halos, night vision problems and ghost-like images or double vision.
One of the most common tests for diagnosing keratoconus is corneal topography, which makes a map of the curvature of the cornea. As the condition progresses into a more advanced stage, the cornea becomes thinner at the point of the cone. The thickness of the cornea can be tested with a test called pachymetry.
There are several effective treatments for keratoconus, including:
Every patient has different needs and the Houston ophthalmologists at International EyeCare Laser & Lifestyle Center base their treatment recommendations on what is best for the individual patient.
Researchers estimate that keratoconus affects 1 in 2000 people. The disease affects men and women alike and there are no known differences between races. Although the cause of the disease is unknown, research has suggested that genetics, allergies and other environmental factors may contribute to the onset of the disease.
Initially, a person with early stage keratoconus will notice a subtle change in their vision. As the disease progresses, one’s vision will fluctuate and frequent changes to one’s glasses or contact lenses often occur. This happens as a result of a thinning taking place within the cornea and bulging caused by one’s normal eye pressure pushing on the weakened front surface of the eye. As the disease continues to advance, the light rays entering the eye become significantly distorted, called irregular astigmatism. The outer portion of the eye begins to bulge, creating what often looks like a cone shape.
Yes, in approximately 90% of keratoconus cases the disease will manifest itself in both eyes. The rate of progression and the timing of the onset of the disease is typically different for each eye.
The onset of keratoconus can occur anywhere between the ages of 8 to 45. In the majority of the cases, it becomes apparent during the teen years and slowly worsens before stabilizing somewhat in the 30’s or 40’s.
Typically, an eye care professional will treat early stage keratoconus with contact lenses or glasses addressing the early vision correction needs of the patient. In later stages, rigid gas permeable contact lenses are often recommended. These lenses are used to improve one’s vision and to brace the bulge in the cornea. In advanced cases, where the patient can no longer achieve adequate functional vision with contact lenses, corneal transplant surgery may be necessary.
A healthy eye is more spherical in shape allowing an image to come into focus clearly.
No, historically very few if any persons suffer from total blindness from keratoconus alone. But in severe cases, one’s vision can be significantly impaired and normal everyday activities may be difficult.
Due to the onset and progression of keratoconus, the weakened cornea loses its natural dome-like shape. As a result, the light rays entering the eye are no longer focused properly, impairing one’s ability to see images clearly.
Intacs are specially designed inserts, made of medical plastic, which are surgically placed under the surface of the cornea. Due to their unique patented design, Intacs are able to remodel the architecture of the cornea re-establishing a more natural dome-like shape and improving one’s vision.
Of those who suffer from keratoconus, approximately 20% will undergo a corneal transplant. In the US, donor tissue is available in most instances and there are more than 4,000 transplants performed for keratoconus each year. The success rate is high although the grafts only last for about 10 years, therefore a young person may have to undergo several corneal transplants. The recovery time for the patient varies and can take more than a year. Contact lenses or glasses are typically required after surgery to achieve an acceptable vision.
A corneal transplant is an invasive surgical procedure, requiring the removal of a section of your cornea and having it replaced with donor tissue. Although successful, it is a delicate procedure with typically a long recovery period.
The Intacs procedure does not require removal of corneal tissue, but rather works on the principle of reshaping your own cornea from within utilizing special designed corneal inserts that provide structure to a weakened cornea. The recovery period is typically short, with visual improvement noticed almost immediately.
In the few cases in which a corneal transplant was performed after an Intacs procedure, there were no complications reported.
The humanitarian device regulations were first established in October 1994. 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 corneal implants were approved under a Humanitarian Device Exemption (HDE) by the FDA in July 2004, allowing Intacs to be used for treating keratoconus. Intacs were first designated a Humanitarian Use Device (HUD) by the FDA’s Office of Orphan Products Development in August 2003.
Intacs are small, corneal ring implants used to correct nearsightedness, keratoconus, and astigmatism.
They work by flattening the cornea into the correct shape. The thickness of the ring can adjust the amount of flattening the ring provides.
Intacs are made of a biocompatible, medical-grade polymer (plastic), also known as PMMA.
Apply a numbing agent to your eye before creating a 2mm opening on the upper edge of your cornea. Through that opening, we insert the Intacs in the correct position. The whole procedure should take less than 20 minutes.
You will definitely need to rest your eyes the remainder of the day following surgery, and most people take at least one to two days off of work before returning to all normal activities.
Most patients begin enjoying improved vision the day after the procedure. Within 12 months, 97% of all Intacs users have 20/40 vision or better.
They are designed to permanently stay in your eyes but can be safely removed at any time if you experience side effects or your vision changes.
If your vision changes with age, you can remove the Intacs and insert new ones that are specifically suited for the state of your vision, or you can remove them entirely. The removal procedure is safe and easy.
For keratoconus, Intacs work by flattening the steep part of the cornea or cone to reduce vision distortions.
Intacs are made of the same material (polymethyl methacrylate or PMMA) used in cataract lens implants for decades. The semicircular segments come in different thicknesses, with thicker Intacs creating more flattening.
You may be eligible for Intacs if you:
Patients with central corneal scarring or extremely thin and steep corneas may not be eligible for Intacs. Corneal transplant procedures may be considered for these very advanced keratoconus patients.
Intacs surgery is a same-day, out-patient procedure. The first step of Intacs insertion is applying antibiotic and anesthetic drops to the surface of the eye. Patients also usually receive oral sedation, so that a driver is needed after the procedure.
A lid holder is applied to prevent blinking during the procedure, which is performed under an operating microscope while the patient is lying flat on the back.
An advanced laser (iFS femtosecond laser) is used to create a 360 degree ring-like tunnel or channel at approximately 70% – 80% depth of the cornea. The tunnel is approximately 3.5 mm away from the center of the cornea, so that most patients do not actually see the Intacs implants in their vision.
Following creation of the channels, one or two half-ring Intacs segments are inserted into the channel. The segments come in different thickness, such that the Intacs size can be customized based upon the shape of the individual cornea.