The slit lamp is essentially a simple and generally under used piece of equipment. It consists of an illumination system and a binocular observation system, which when correctly aligned will result in a coincidental focus of the slit and microscope.
Basically a short focus projector projecting an image of the illuminated slit aperture on to the eyes. This part of the system should be flexible to allow various sizes and the shape of the slit beam. Usually a rheostat is incorporated and the lamp house can be rotated. Neutral density, cobalt blue and the red free filters are usually available, and occasionally a diffuses and polarizes.
Commence the examination using the 10x eyepieces and the lower powered objective e.i. 1x. Use the lowest voltage setting on the transformer. Select the longest slit length by means of the appropriate lever. Adjust the chin rest by means of control so that the patient's eyes are approximately level with the black marker on the side of the head rest. Adjust the height of the slit lamp until the slit beam is centered vertically on the patients eyes. Focus the slit beam in the eye by moving the joystick either toward or away from the patient. Coarse positioning can be effective without using the microscope. The slit width is variety by rotating either the left hand or right hand knurled control. To vary the angle between illumination and the microscope use one and other of these same controls as handles.
The slit should be set primarily in the vertical position, by any desired inclination can be achieved by means of the ball handle (notches at 45 degree, 90 degree, 135 degree, stop at 0 degree to 180 degree). By tripping the latch and the tilting the slit Lamp column, the beam can be introduced from as much as 20 degree below the horizontal. This is mainly used for carrying out goniscopy.
For observation by sclerotic scatter or other dissociated forms of examination the centering screw is loosened, so that the slit image can be moved away from the center of the field of observation. The image is centered again by tightening the screw. Carry out the techniques described below.
* Eyepieces 10x, 15x
* Objective 1x, 1.6x
* Total Magnification 10x, 16x, 24x
Illumination Unit
* Slit Image Rotation 0 to 180 degree
* Tilting Illumination Up to 20 degree
* Filter Disc Cobalt Filter, Green Filter, Yellow Filter Natural Density and Open Aperture
* Slit Diaphragm Disc Wedge Shape diaphragm of infinitely variable slit lengths
* Halogen Lamp 12 Volts 50 Watts
Standard Accessories
* Replacing Lamp Plastic Breath Shield
* Testing Rod Dust cover and fuse
* 15 Eyepieces Spare Lamp