Automated Keratometry
Automated Keratometry is a diagnostic test used to measure the curvature of the cornea, which is the clear, dome-shaped front surface of the eye. The corneal curvature is crucial for focusing light on the retina and plays a significant role in vision. This test provides valuable information for assessing corneal health, determining refractive errors, and planning for surgeries such as cataract surgery, LASIK, or corneal transplants.The automated keratometer is a specialized instrument that provides accurate, reproducible measurements of the corneal curvature, usually in the form of diopters (D) or the radius of curvature (mm). These measurements are essential for diagnosing conditions like astigmatism, keratoconus, and corneal abnormalities.
How Automated Keratometry Works
The Instrument:
An automated keratometer consists of a light source, typically a mire (a target pattern), and a photodetector. The light is directed onto the cornea, and the reflections from the corneal surface are captured by the photodetector.Measurement Process:
- The patient is asked to fixate on a target in the device. The automated keratometer projects a grid of light onto the cornea, which is reflected back.
- The instrument measures the reflections and uses them to calculate the curvature of the cornea. The instrument then automatically generates two key readings: the horizontal and vertical curvatures of the cornea, typically reported as K1 and K2.
Output Data:
The output usually includes:- Keratometric readings (K1 and K2), representing the steepest and flattest meridians of the cornea.
- Axis: The orientation of the steepest and flattest meridians.
- Average K-value: A composite of the curvature readings.