Preparation before measurement
1. Clean the damaged lens with distilled water and do not dry it with organic cotton swab;
2. Adjust the tonometer reading drum to the scale "1";
3. Adjust the crack spot to the maximum and the filter to cobalt blue;
4. The slit lamp part and the microscope part have an included angle of 40 ~ 60 degrees;
5. The microscope is magnified by 10 times;
6. 1% dicaine is used for ocular surface anesthesia, and both eyes are anesthetized at the same time to reduce blinking;
7. Put fluorescein paper or fluorescein solution in the conjunctival sac of the tested eye for eye staining;
8. Put the patient's lower jaw on the jaw bracket, and the forehead is close to the frontal bracket;
9. Let the patient open his eyes and look straight ahead. If necessary, stretch the patient's eyelids by hand, but do not press the eyeballs;
operation
1. When there is no target eye, the slit lamp shines on the prism flattening head of Goldmann tonometer. When refracted to the slit lamp eyepiece, we can see a reflection ring at the top and bottom. During measurement, this ring is always the same, which is temporarily called a fixed reflection ring.
2. Moving the slit lamp towards the target eye from a distance, you can see that there is a # small reflective ring on the left and right of the horizontal. It is caused by the slit lamp shining on the corneal surface and being refracted to the eyepiece after reflection. It is temporarily called the moving reflective ring.
                            
3. Then slowly move the slit lamp forward. From the slit lamp eyepiece, we can see the refraction of the corneal surface. The reflective ring of the slit lamp eyepiece is also slowly close to the middle. The upper small reflective ring moves towards the fixed reflective ring above the horizontal line, and the lower small reflective ring moves towards the fixed reflective ring below the horizontal line.
4. The upper small reflective ring is close to the fixed reflective ring above the horizontal line, and the lower small reflective ring is also close to the fixed reflective ring below the horizontal line, which means that the corneal surface is about to contact with the surface of the prism flattening head of Goldmann tonometer.
      
5. At this time, gently push the handle perpendicular to the slit lamp on the operating table (Note: gently push the top of the handle, not horizontally, to prevent the moving distance from being too large), and you can see that two green half rings appear.
6. At this time, keep the slit lamp still, slowly rotate the bolt button applying pressure until the inner edges of the two half rings are tangent, and then read from the reading drum.
                    
7. Repeat the above operation for three times. If the readings of each time are basically consistent, it means that the measurement is correct. The average value of the three times is the measured intraocular pressure value.
8. After the measurement, operate the handle of slit lamp to quickly evacuate the tonometer from the patient's cornea.
 
 
Guide for calibration of flattened tonometer
1. Take out the tonometer weight. The weight of the weight and base are 2G.
 
2. Place the tonometer horizontally and put the weight seat in the bayonet of the prism lens.
 
3. Place a mirror on the side of the pressure knob marked with scale, and the scale of the tonometer can be observed through the mirror.
 
4. Rotate the pressurization knob to make the balance bar in the balance position.
 
5. Observe whether the scale mark stays at "2" through the mirror, and it is normal that the error is within one grid.
 
6. Add a weight, continue to adjust the tonometer to make it in a balanced position, and observe whether the scale line stays at the "4" position. Continue to add weights in turn. If the measured positions are accurate, it indicates that the tonometer is accurate.
 
7. If the tonometer scale has deviation, and the deviation of the weight added each time is fixed, it indicates that the zero position of the tonometer is inaccurate. Unscrew the screw at the top of the compression knob, loosen the scale knob, adjust the tonometer in the horizontal position, align the scale knob with the scale mark when the balance bar is in the balanced position, fix it with adhesive tape, and then tighten the screw.
  
8. If the zero position of the tonometer is correct, but there is a deviation in the scale after adding the weight, it indicates that there is a problem with the internal spring device, and the tightness needs to be adjusted by adjusting the bottom screw.