If you live in the San Antonio Texas area and have keratoconus we are offering second opinions for diagnosis and treatment options. Our San Antonio keratoconus eye doctor can develop a custom treatment protocol that makes sense for your level of keratoconus. Because ophthalmologists handle the treatment of keratoconus in various ways we strongly encourage a keratoconus second opinion. New cutting edge treatment options are coming to fruition in treating this cornea disease and we want our patients to be properly informed about their options.
What is Keratoconus?
Keratoconus literally means cone-shaped cornea
(American Academy of Ophthalmology, 2011)
Keratoconus Definition – An eye disorder characterized by an irregular corneal surface (cone-shaped) resulting in blurred and distorted images. Keratoconus is a condition of the eye, which causes the cornea to thin out, resulting in a protrusion of the cornea. Due to the protrusion, the front of the eye appears cone-shaped, causing the light passing through to be distorted.
If the cornea is not smooth, the images passing through to the retina will not appear properly. These distorted images can cause halos, starburst surrounding lights, blurred vision, multiple images, and ghosting. Keratoconus is a progressive condition that often develops in the teens and into early adulthood, gradually worsening over time.
Signs and symptoms of keratoconus may change as the disease progresses.
The symptoms a keratoconus patient may have included:
- Blurred or distorted vision
- Increased sensitivity to bright light and glare
- Problems with night vision
- Many changes in eyeglass prescriptions
- Light Streaking
What Causes Keratoconus?
Your eye is composed of tiny fibers of proteins called collagen, which function to secure the cornea in place and prevent the tissue from protruding. Once those fibers become weak, they are no longer able to hold the shape, resulting in the cornea gradually becoming cone-shaped. The exact cause of why the fibers weaken has yet to be determined. Keratoconus is known to be hereditary. If you have or have had keratoconus, it is important to obtain an eye exam for your child so their eye health can be closely monitored.
Other risk factors for this condition include:
- Overexposure to UV rays
- Certain diseases such as arthritis or allergy conditions
- Down Syndrome
- Poorly fitted contacts
- Chronic eye rubbing
Keratoconus is not associated with physical symptoms such as inflammation and redness; therefore, this condition may go undetected for a long period of time. Most individuals who develop keratoconus will have an occurrence in both eyes. Individuals with undiagnosed keratoconus typically notice their vision deteriorating in one eye and gradually to the next eye. They may complain of halos, glares, and ghosting of images.
What Are My Treatment Options?
Glasses or Soft Contacts – In the early stages, glasses or soft contacts can deliver immediate but temporary vision correction. Unfortunately, due to the progressive nature of the condition, there will be a point where glasses and contacts will no longer work.
Rigid gas permeable (RGP) contact lenses – As the condition worsens, RGPs and other specialty contacts are the next option.
INTACS – We also recommend considering INTACS when a patient becomes contact lens intolerant to any particular contact lens type. INTACS corneal ring segments can also improve the stability of a cornea and reduce progression of keratoconus. A study that appeared in the Journal of Refractive Surgery concluded that 92.9% of eyes with progressive keratoconus did not progress after INTACS were implanted.
(Bedi et. al. Refractive and topographic stability of Intacs in eyes with progressive keratoconus: five-year follow-up. J. Refract Surg. 2012;28(6):392-396)
- INTACS inserts can defer the need for a corneal transplant procedure.
- INTACS inserts can be surgically removed or replaced.
- INTACS inserts may improve vision by creating a more regular surface for the cornea, which may allow more successful contact lens fit, glasses or both.
- INTACS inserts may reduce the nearsightedness and astigmatism associated with keratoconus.
- INTACS inserts preserve the central part of the cornea which is most important for vision.
- Rigid gas permeable lenses are designed to comfortably sit on top of the cone-shaped cornea. The lens creates a new refractive surface while providing substantial lubrication at the space in between the front of the eye and the lens.
- Specialty design keratoconic lenses are also available and may be a more comfortable option for the severity of your condition.
Crosslinking – Corneal Crosslinking is another effective way to treat moderate keratoconus. This is a minimally invasive, FDA-approved procedure that combines the use of riboflavin eye drops as well as ultra-violet A (UVA) light to treat progressive keratoconus by strengthening the cornea.
This outpatient procedure takes about an hour, and you will be given numbing drops and relaxing medication to keep you comfortable during the procedure.
In the later stages, iron will begin to deposit around the protrusion of the cornea, causing the tissue to further thin and develop a secondary condition known as Vogt’s Striaes. Vogt’s creates a white line deep in the stroma of the eye, which becomes visible around the cornea and base of the protrusion. Another secondary condition, found in rare cases of keratoconus, is Acute Hydrops; a condition where water floods the thinned areas of the cornea, which causes corneal scarring.
If you are experiencing keratoconus, our San Antonio keratoconus eye doctors at Parkhurst NuVision will guide you in the best direction for your treatment options! See the information below regarding corneal transplants.
What is a corneal transplant?
A corneal transplant, also known as a corneal graft, or as a penetrating keratoplasty, involves the removal of the central portion (called a button) of the diseased cornea and replacing it with a matched donor button of the cornea. Corneal grafts are performed on patients with damaged or scarred corneas that prevent acceptable vision. This may be due to corneal scarring from disease or trauma. In this photo of a recent transplant, the stitches can be seen clearly on the right side.
A common indication for keratoplasty is keratoconus. The eye-care practitioner must decide when to recommend keratoplasty for the keratoconic patient. This is often not a simple, straightforward decision. Keratoplasty for keratoconus is highly successful; however, there is a long recovery period and a risk of severe ocular complications. A number of factors must be considered in deciding when to do a keratoplasty. One of the most important is the patient’s functional vision. If the best acuity with their contact lenses prevents them from doing their job or carrying out their normal activities, a transplant must be considered. The actual measured visual acuity may be quite different for different patients. One patient may find that he/she cannot do their job with 20/30 acuity while another patient may be very satisfied with 20/60 acuity.
Very careful contact lens fittings are necessary before recommending a corneal transplant. One study found that 69% of keratoconus patients, most referred for transplant, could be successfully fit with contact lenses if special lens designs were used. Thus, prior to transplant, every effort should be made to optimally fit the patient with contact lenses, especially if there is not significant corneal scarring affecting vision. However, a few patients become intolerant to contact lenses and require a transplant earlier than otherwise would be necessary. If the patient has a large area of thinning, a very debentured cone or significant blood vessel growth into the usually clear cornea, called revascularization, a transplant may be performed earlier than otherwise indicated by the visual performance, as these factors may require a larger than normal transplant button size and/or increase the chance of rejection if allowed to advance too far.
Patients Need a Corneal Transplant When:
- Vision is not good enough to perform daily activities.
- There is pain or recurring infections in the damaged cornea
Healing After Corneal Transplant
The healing process following transplant is long, often taking a year or longer. The time from surgery to the removal of the stitches is commonly 6 to 17 months. The patient may be on steroids for months. Initially following surgery the donor button is swollen and even following healing the button is usually thicker than the corneal bed in which it rests.