Oculus Hertel Mirror Exopthalmometer

The Hertel mirror exophthalmometer is used for precise measurement of the degree of forward displacement of the eye in the sagittal axis (proptosis). The distance between the lateral orbital rim and the apex of the cornea serves as the dimension of the measurement.

Overall dimensions are 26x 260 x 78 mm. Weight is 111 grams. Scale for orbital wall (Scale on track) goes from 75 mm to 135 mm. The scale to measure the proptosis (Inner scale mirror) ranges from 0 to 35 mm.

Operation
* Sit down opposite the patient.
* Using both hands, position the blue supports of the mirror exophthalmometer (2, 5) at the temporal lateral orbital walls.
* Make sure that the exophthalmometer is initially firmly propped against the right orbital rim (whereby the edge of the bone should be felt against the lowest point of the blue support).
* With your right hand, adjust the moveable part on the slide rail so that the left orbital rim is also positioned at the lowest point of the blue support.
* Take a reading of the orbital rims at the top on the scale on the sliding rail (1).
* Note down this value for future measurements.
* Ask the patient to open his eyes wide and to look straight ahead.
* Start by measuring the exophthalmos of the patient’s right eye.
* With one eye, look into the left mirror housing at the mm graduation on the inner scale.
* Move your head from side to side until the red fixation line is located at the 18 mm mark.
* Take a reading of the mm mark at which the patient’s corneal apex is located.
* Now conduct the measurement of the exophthalmos of the left eye.