What Is Keratoconus?
Keratoconus is a progressive disease in which the cornea thins and changes shape. In people with keratoconus, the cornea doesn’t have enough collagen fiber crosslinks, which serve as a kind of structural support. Without these collagen crosslinks, the cornea begins to bulge out in a cone-like shape. This change in the curvature of the cornea results in astigmatism (either mild or severe distortion) and usually nearsightedness. The disease may also cause swelling and scarring of the cornea and vision loss.
Signs and symptoms of keratoconus may change as the disease progresses and include:
- Blurred or distorted vision
- Increased sensitivity to bright light
- A need for frequent changes in eyeglass prescriptions
- Sudden worsening or clouding of vision
Causes of keratoconus include:
- Eye trauma, such as long-term use of hard contacts
- Eye diseases, such as retinitis pigmentosa, retinopathy of prematurity, and vernal keratoconjunctivitis
- Other diseases including Down syndrome, osteogenesis imperfecta, Addison’s disease, Leber’s congenital amaurosis, and Ehlers-Danlos syndrome
Although rare, a similar condition to keratoconus can develop called post-LASIK ectasia, in which the cornea starts to bulge forward at a variable time after LASIK, PRK, or SMILE corneal laser eye surgery.
During the beginning stages of the disease, the condition is correctable with glasses or soft contact lenses. As the disease progresses, though, rigid gas permeable contact lenses or other types of lenses are usually necessary.
Based on the condition of your eyes, your eye doctor may also recommend one of the following two treatment options:
Corneal Collagen Cross-linking (PACK-CXL)
To slow the progression of the disease, your ophthalmologist may recommend a corneal collagen cross-linking procedure. This cutting-edge treatment uses a special type of ultraviolet light to stabilize and strengthen the cornea by creating new links between collagen fibers within the cornea. This then slows the changes to the shape and curvature of the cornea.
During a corneal cross-linking procedure, your doctor will first apply riboflavin (vitamin B-12) eye drops and then shine a specific type of ultraviolet light directly onto your cornea. The procedure causes new corneal collagen cross-links to develop, leading to a stiffer, stronger cornea.
Corneal cross-linking is an outpatient procedure that typically lasts about an hour. Patients typically do not experience any discomfort during the procedure thanks to mild sedation and numbing anesthetic drops applied to the eyes.
Corneal Transplant (Keratopathy)
For severe or advanced cases of keratoconus, a corneal transplant may be necessary.
At Ophthalmic Consultants of the Capital Region, our corneal specialist uses a laser-assisted procedure called FLAK (femtosecond laser-assisted penetrating keratoplasty) to remove the damaged cornea and replace it with a donated cornea. The laser technology allows our specialist to create the most optimal fit with the new cornea, resulting in a faster healing of the transplant, quicker recovery of vision, and better optical quality.
Patients don’t feel any pain thanks to the use of a sedative and local anesthetic. During the procedure, your doctor will remove a button-sized disk of the abnormal or diseased corneal tissue and then the donor cornea, cut to fit, is placed in the opening. Your doctor will then use a fine thread to stitch the new cornea into place. The stitches may be removed at a later visit when you have a follow-up appointment with our specialist.
Once the cornea transplant is completed, you can expect to receive several medications including eye drops, wear an eye patch to protect your eye as it heals after surgery, and return for follow-up exams so your cornea specialist can monitor the healing progress and restoration of vision.
Most people who receive a cornea transplant will have their vision at least partially restored, although the majority of people will still need glasses or contact lenses to see clearly.