Corneal Strengthening and Stiffening

Certain eye diseases may require corneal strengthening or stiffening. Parker Cornea is a leader in the field of these state-of-the-art procedures.

Corneal Cross-linking

UV-corneal cross-linking is an FDA approved procedure for the treatment of progressive keratoconus.  The procedure involves the administration of a specially formulated riboflavin solution to the corneal surface which is then activated by a UV-laser. This process tightly links the cornea’s fibers together, strengthening the cornea, and reducing the risk of continued disease progression.

Corneal cross-linking is a routine procedure performed comfortably in our clinic. You are encouraged to eat a light meal beforehand, and to wear loose, comfortable clothing.  An ophthalmic technician trained in corneal cross-linking will meet you on the day of your procedure and remain with you for the duration of the treatment, which lasts approximately one hour.  Most of this time is spent receiving riboflavin eye drops. Your corneal specialist will administer your UV laser treatment. This laser is painless and invisible. After your procedure, you are invited to enjoy a drink and a treat in our recovery area before going home.

Corneal cross-linking is a covered procedure for the vast majority of medical insurances. A variety of options exist for financing treatment, some of which may be found here.

The biggest risk of corneal cross-linking is that it would fail to control the progression of your disease. Normally, the success rate of crosslinking approaches 98%, which means that 2% of eyes (1/50 patients) will continue to experience disease progression after treatment. In these patients, a second treatment is often successful.

Rarely, cross-linking may be associated with other problems, including infection and the development of corneal haze.  Infection is rare and usually preventable with the use of antibiotics. Significant haze is extremely uncommon, but can be visually limiting in rare cases.

Corneal cross-linking will not undo the damage that has already been done.  Therefore, it is important to be treated early, before significant damage to accumulates. To regain lost vision, additional procedures after cross-linking may be necessary.

Bowman Layer Grafting

The Bowman layer is naturally the stiffest and strongest layer of the cornea. In certain corneal diseases (for example, keratoconus and other forms of ectasia), the Bowman layer becomes damaged, weakening and destabilizing the cornea, resulting in compromised corneal shape and optical transmission.

Recently, however, it has become possible to replace this damaged corneal layer.  An isolated “Bowman layer transplant” involves grafting a normal, healthy Bowman layer onto the surface of an eye with pre-existing Bowman layer damage.  This transplanted Bowman layer restores the normal strength and clarity of eyes with previous Bowman layer damage.

The best candidates for Bowman layer grafting are patients with corneal instability caused by prior radial keratotomy (RK), and patients with keratoconus who cannot undergo corneal cross-linking.  Other patients may be candidates as well, including those with recurrent corneal erosions caused by epithelial basement membrane dystrophy and central corneal scarring caused by prior herpetic keratitis.

Until recently, it was not thought possible to replace only the cornea’s Bowman layer, so patients with Bowman layer damage were usually referred for full-thickness (complete) corneal transplantation.  Transplanting the entire cornea is a significantly larger and more dangerous operation, with many more risks and a much longer recovery period, compared to Bowman layer grafting alone.

Bowman layer transplantation involves no cuts into your eye, no stitches, and no need for long-term eye drops. In contrast, full-cornea transplantation involves stitches which must remain in the eye for years and a life-time dependence on anti-rejection eyedrops.

Drs Jack and John Parker have performed more Bowman layer transplants than any other doctors in the world.  They are the authors of many scientific articles and book chapters on the technique, and regularly are called to lecture on the subject internationally.