Houston Keratoconus Treatment
The primary purpose of the cornea (the clear surface of the eye) is to focus images on the retina. Normal corneas are curved and have a rounded shape, like a basketball. Collagen is responsible for helping the cornea withstand constant pressure from inside the eye and maintain its curvature. If the collagen weakens, the cornea starts to yield to the pressure and bulge or become cone-shaped. This condition, called keratoconus, has an effect on how the cornea focuses images on the retina, thus affecting vision. Keratoconus affects approximately one out of a thousand people. International EyeCare Laser & Lifestyle Center treats cases of keratoconus in Houston and the surrounding area.
Causes of Keratoconus
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.
Noticing and Diagnosing Keratoconus
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:
- rigid, gas-permeable contact lenses
- the use of radio energy to reshape the cornea
- corneal implants to reshape the cornea
- corneal transplant
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.
Frequently Asked Questions
Who gets keratoconus?
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.
What are the symptoms?
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.
Does keratoconus affect both eyes?
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.
What is the usual age of the onset of keratoconus?
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.
How can it be treated?
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.
Will I go completely blind?
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.
How do Intacs work and how might they help me?
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.
Tell me more about corneal transplant surgery.
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 acceptable vision.
What are the advantages of the Intacs procedure as compared to a corneal transplant?
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.
What is a Humanitarian Device Exemption (HDE)?
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.
What are Intacs?
Intacs are small, corneal ring implants used to correct nearsightedness, keratoconus and astigmatism.
How do Intacs work?
They work by flattening the cornea into the correct shape. The thickness of the ring can adjust the amount of flattening the ring provides.
What kind of material are Intacs made of?
Intacs are made of a biocompatible, medical-grade polymer (plastic), also known as PMMA.
What is the implant procedure for Intacs?
At ClearView Eye and Laser Medical Center, your comfort is our number one priority, so if you are nervous or anxious about the procedure, Dr. Feldman will first administer a mild sedative. Next, she will apply a numbing agent to your eye before creating a 2mm opening on the upper edge of your cornea. Through that opening, Dr. Feldman will insert the Intacs in the correct position. The whole procedure should take less than 20 minutes.
Will I need to take time off work for the procedure?
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.
How long will it take for my vision to improve after the procedure?
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.
How long will the Intacs stay in my eyes?
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.
What happens if my vision changes over time?
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.
How do Intacs work?
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.
Are you a candidate for Intacs?
You may be eligible for Intacs if you:
- Are 21 years of age or older
- Have keratoconus, pellucid marginalis, or other conditions marked by corneal bulging and thinning
- Have unstable vision or an irregular corneal shape after LASIK
- Have visual distortion even with glasses or contact lenses
- Are unable to wear your contacts comfortably
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.
What is involved in the Intacs procedure?
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.
What happens after the procedure?
Following the procedure, the patient is advised to rest overnight. Antibiotic, anti-inflammatory, and artificial tear drops are used for several days or weeks. There is some fluctuation in the vision and some mild eye irritation. However, you do not feel the Intacs because they are below the skin of the cornea.
Usually, the vision will improve within a few days but full healing can take over 3 months. Some patients may start wearing temporary soft contact lenses to improve their vision during the corneal healing phase. A final glasses or contact lens prescription will be measured 3 – 6 months after the procedure.
Results of Intacs will depend on the degree of keratoconus or corneal irregularity in each individual. However, Intacs may not halt progressive bulging and steepening of the cornea from keratoconus or similar corneal diseases. Clinical studies of investigational procedure such as corneal cross-linking to stiffen the corneal collagen and prevent bulging are underway. Intacs patients may be candidates for future cross-linking procedures.
Are Intacs reversible?
Intacs are designed for long-term vision correction, but are reversible. Intacs may not sufficiently improve the vision in about 5% of patients. In these cases, Intacs can be surgically removed from cornea or can be replaced with different size ring segments. If Intacs are permanently removed, the vision will likely return to the way it was prior to surgery after a few months. Following removal, Intacs usually do not leave behind scar tissue, although this possible.
What are potential complications of the Intacs procedure?
As with any surgery, infection of the corneal tissue surrounding the segments or the insertion incision site is possible. Usually this would occur within the first few weeks of the surgery and can be treated with antibiotic drops or with removal of the segments. For this reason, antibiotic drops are applied prior to the surgery and for several days afterwards. It is possible for the Intacs implants to shift from their original position, in which case they may be repositioned or permanently removed. It is also possible for the corneal tissue overlying the implants to thin, in which case the implants may require removal.
During the surgery, it is possible for the tunnel or channel for the implants to be too deep or too shallow within the substance of the cornea, such that implant insertion is not possible. It is also possible for perforation of the corneal tissue to occur during insertion of the Intacs segments.
Some patients experience visual symptoms including difficulty with night vision, glare, halos, blurry and fluctuating vision.
What are the advantages of the Intacs procedure as compared to a corneal transplant?
A corneal transplant involves replacing either a portion of the cornea or of the entire central cornea with corneal donor tissue. As it is a more invasive surgery, its complications can be much more severe. It typically requires a long recovery period of several months to a year.
The Intacs procedure does not require removal of corneal tissue, but rather reshapes the weakened cornea by adding mechanical support to it. The recovery period is typically shorter, with more rapid improvement in vision. The synthetic material of Intacs is not at risk for rejection the way donor transplant tissue is.
In some cases, if Intacs are not effective, patients can proceed with corneal transplantation.
What is Intacs?
Intacs (also known as Intracorneal Rings, ICRs, and Corneal Ring Segments) are two tiny half rings designed to permanently correct vision when placed within the eye. They are made of a special biocompatible plastic that has been used in contact lenses and cataract surgery for nearly 50 years. Inside the cornea, they cannot be felt and are practically invisible.
Intacs is highly effective in treating Keratoconus (a thinning disorder of the cornea that causes distortion of the corneal shape and therefore reduced vision).
How does Intacs work?
Anesthetic drops are used to numb the eye, which is held open throughout the procedure to prevent blinking.
Step 1: A single, small opening is made in the cornea.
Step 2: The eye is prepared for Intacs™ placement.
To stabilize your eye, the centering guide is placed on the surface for one to two minutes. During this time, two semicircular tunnels are made in the cornea. The Intacs™ will be placed in these tunnels.
The cornea has several layers to it, like a pad of paper. Making a place for the Intacs™ is like separating two pages just enough to create a space.
Step 3: The Intacs™ segments are placed.
After the second Intacs™ segment is placed, the small opening in the cornea is closed.
Step 4: You enjoy your new vision!
What are the benefits of Intacs?
- Immediate vision improvement
- No corneal tissue removed
- Intacs can removed or replaced
The procedure for Intacs™ is safe and quick. Intacs™ reshape the curve of your cornea so that light rays focus properly on the retina. Objects in the distance, which once appeared blurry, become sharp and clear.
Who is a candidate for Intacs?
- Nearsighted patients with a prescription between -1.00 and -3.00 diopters
- Astigmatism of 1.00 syl or less
- At least 21 years or older
- Patients with Keratoconus
- Healthy eyes, free from injuries
There may be times when IQ Laser Vision may need to turn away patients because they are not a good candidate for the procedure because our number one concern is not the number of patients we bring in but the quality of care and high level of service we provide. That is why it is important to come in for our FREE CONSULTATION, in order for IQ Laser Vision to determine your candidacy and provide the best vision correction options for you.
What can you expect?
Vision improvement can be noticed right after the Intacs have been inserted. Most patients report feeling no pain at all during the procedure. Patients can usually resume regular activities within 2-3 days after the procedure. Typically full stabilization is achieved after one month, in which most healing occurs during the first 7 days. In rare cases, patients report the presence of the Intacs the day after surgery, but that foreign body sensation disappears as the eye heals.
In U.S. clinical studies, 97 percent of patients achieved 20/40 or better with Intacs (Functional Vision – 20/40 or better – DMV minimum for operating a moving vehicle).
What are the risks of Intacs?
Possible side effects may include:
- Light sensitivity
- Decreased clarity in dim light
- Glare or haloes from lights at night
- Blurry or Double vision
- Fluctuating distance vision
These side effects typically disappear as the eye heals and generally occur in rare cases.
All risks are discussed and addressed before, during and after the procedure. IQ Laser Vision is dedicated to answering any and all questions you may have to ensure complete conformability and proper expectations with the procedure.
If you are experiencing blurred vision and glasses aren’t helping, contact International EyeCare Laser & Lifestyle Center to schedule an appointment with our team for an eye examination.