| umls-concept:C0221831 | skos:definition | UMD: Ophthalmic systems designed to objectively determine the configuration of the anterior corneal surface (i.e., its topography) and the refractive power by projecting concentric circular rings on the cornea. The systems typically consist of a videokeratoscope that projects the illuminated rings onto the cornea and captures the reflected image through a video camera and the image-processing software system that analyzes the cornea topography data (e.g., curvature, slope), calculates the refraction power, and displays the data graphically. The devices are used mainly for planning refractive corneal surgery, fitting contact lenses, or diagnosing some corneal disorders. | lld:umls |
