|
Specular Reflection Technique
PURPOSE To eva luate the corneal endothelium.
INDICATIONS
The use of specular reflection is indicated when other examination findings suggest corneal endothelial dysfunction.
STEP-BY-STEP PROCEDURE
1. Adjust the slit beam to a medium width parallelepiped.
2. Begin with the magnification on a low or medium setting.
3. Focus the parallelepiped on the cornea with the illumination arm set approximately 30°from the straight ahead position.
4. Using the joystick, adjust the position of the microscope or change the angle of the illumination arm until the slit beam intersects the reflection of the light filament on the cornea. This is the point at which the angle of reflection is equal to the incident angle of the light. When properly set , you will see an area of bright glare from the front surface of the cornea. This will be visible through one ocular only.
5. Increase the magnification to the highest setting (25× or 40×).
6. Adjust the focus of the slit lamp so that it is sharply focused on the corneal endothelium. Exact focus is critical. Observe the mosaic pattern of the endothelial cells (see Figure 5-12).
7. To observe other areas of the endothelium, it is necessary to move the entire slit lamp and readjust the illumination arm.
RECORDING
·The results of this procedure are listed in the slit lamp recording section under “cornea.” It is not necessary to indicate that specular reflection was used.
·Record your observations for each eye separately. |
