Keratoconus Detection by Ultrasound

Keratoconus is the most common degenerative disease affecting the cornea. As keratoconus
develops, the cornea thins and bulges. Eventually, a corneal transplant may be needed to
maintain vision. In its earliest stages, the disease is particularly difficult to detect.
This is of great importance to the corneal refractive surgeon because surgical treatment of a
keratoconic cornea will weaken it and greatly accelerate the occurrence of symptoms. Early
detection of keratoconus will benefit patients because of the recent development of methods
for strengthening the corneal stroma and preventing disease progression.

The investigators have developed a technique based on the use of high resolution ultrasound
for imaging the cornea and measuring the thickness of its component layers, including the
epithelium and the stroma. In early keratoconus, as the anterior stromal surface begins to
bulge forward, the epithelium will thin above the apex of the bulge and thicken around it, to
maintain a smooth anterior surface. The investigators have also developed methods for
characterizing the elastic properties of the cornea by inducing and measuring surface
displacements in response to a pulse of acoustic radiation force.

The investigators' goal is to reduce the percentage of screened cases deemed
keratoconus-suspect by at least a factor of two by allowing an unambiguous diagnosis of early
keratoconus. This would provide two major benefits; (1) to be able to predict eyes with
higher risk of developing ectasia after corneal refractive surgery, and (2) early diagnosis
would allow earlier treatment of the condition with collagen crosslinking, preserving the
cornea from disease progression.

Inclusion Criteria:

- Clinical diagnosis of keratoconus (KC) or keratoconus-suspect

- Blood relation of person with KC

- Age-matched normal of KC subjects

- Ability to sit still in front of ultrasound unit and lie on exam table

Exclusion Criteria:

- Other eye disease