Eyelid pressure: inferences from corneal topography changes

摘要: Purpose:: The cornea is the principal optical element of the eye so the regularity of its surface topography is critical for visual optics. However the cornea is known to be susceptible to forces exerted by the eyelids. These corneal changes are bands of ‘wave-like’change that are parallel to the position of the eyelid margin. There is little known about eyelid pressure on the cornea which is dependent on eyelid force and the contact area. By analysing the depth and width of corneal topography changes after various downward gaze tasks, inferences could be drawn about upper and lower eyelid pressure.Methods:: Corneal topography changes due to eyelid pressure were measured using the Medmont E300 Corneal Topographer (Medmont Pty. Ltd. Victoria, Australia), for eighteen subjects aged between 18 and 29 years. Four conditions were considered, consisting of two downward gaze angles (20 and 40) and two …