Biomicroscopy of the cornea
Last reviewed: 31.05.2018
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Biomicroscopy of the cornea is performed to systematically identify clinical signs, determine the localization, depth and size of corneal damage .
Method of direct illumination by diffuse light
Used to detect gross changes.
- A narrow oblique oblique light slot allows one to examine each quadrant of the cornea.
- The additional narrowing of the light beam makes it possible to visualize very thin optical parts.
- The change in the height of the coaxial beam is used to measure the size of the damage.
- The direction of the light gap can be changed by rotating the lamp body.
- When the beam passes through all layers of the cornea determine the thickness and depth of its damage.
- The nature of light can be changed with the help of filters. With a red filter, red objects appear to be black, which increases the image contrast when examining vascular structures and when staining with Bengal pink. The blue cobalt filter is used for staining with fluorescein.
Scleral Scattering Method
The light gap is decentered so that the light falls on the limb, while the microscope is focused in the center. Light is distributed within the cornea due to a full internal reflection and reaches the opposite limb. The damaged area of the cornea is illuminated when the light beam reflected in the thickness of the cornea is scattered. This method is important in determining subtle changes in the cornea.
Method of investigation in reflected light
Use light reflected from the iris or the fundus to detect subtle changes in the endothelium and epithelium, corneal precipitates and small blood vessels.