What type of illumination is mainly used to detect corneal edema?

Sclerotic scatter is a specific type of illumination technique used in slit lamp examination that is particularly effective for observing corneal edema. This method takes advantage of the way light interacts with the cornea. When the cornea is edematous, its refractive properties change due to the accumulation of fluid, causing light to scatter in a manner that highlights these areas.

In sclerotic scatter, a narrow beam of light is directed at the limbus (the border between the cornea and the sclera). The light penetrates the cornea at an angle, and because of the changes in refractive index caused by edema, some of the light is reflected back into the observer's view. This results in a distinct halo effect around the cornea, making it easier to identify areas of swelling and assess the extent of corneal edema. The technique allows for a clear visualization of corneal morphology and pathology.

Other illumination types, such as the conical beam or parallelepiped, serve different purposes. The conical beam can be useful for examining the depth of structures but is not specifically designed to highlight corneal edema. The parallelepiped provides a wider view of the cornea but may not effectively illuminate the subtle changes associated with edema. Ind