You should understand the general conditions related to binocular vision before performing a synoptic examination for the patient.
1. Medical history: time and condition of onset.
2. Check visual acuity, alternate gaze or monocular gaze, and the nature of the gaze.
3. Covering test: To check whether the patient has hyphenia, obvious strabismus, constant strabismus or intermittent strabismus, and extraocular muscle paralysis.
When the patient sits in front of the same camera for examination, we should know the general condition of the patient so that we can avoid diagnostic errors. For example: When encountering patients with unclear boundaries between apparent oblique and hypocytic obliquity, the visual inspection of such patients found that the binocular vision of such patients is severely impaired. If the doctor is familiar with the situation and can better guide the patient to perform the examination, it can save time and it is easier to find abnormal conditions.
If the doctor thinks that the patient may have binocular vision, (for example, strabismus is late onset and intermittent), first perform a subjective examination and ask the patient to push and pull the joystick of the synoptograph whose subjective oblique angle of view matches the objective oblique angle of view. Draw a clear conclusion. If the two examination results are inconsistent, the doctor should suspect that the patient has abnormal retinal correspondence or inhibition, and write down the examination results for further examination and analysis.
First adjust the patient’s chin rest and forehead rest, make the patient look at the picture in the eyepiece, adjust the instrument to adjust the pointers of all the dials to 0o, pay special attention to the vertical and rotating dials, adjust the height of the chin rest, so that the patient The eyes are aligned with the eyepieces of the synoptograph, which is also convenient for the doctor to observe the patient’s eye movements. The eyepiece distance should be equal to the patient’s interpupillary distance. The interpupillary distance of a strabismus patient is the distance between the pupils when the eyes are in their original positions. The brightness of the lights in the two lens barrels should be equal or the light in front of the amblyopic eyes should be slightly brighter. Patients with abnormal binocular vision should pay attention to that the patient's head position should be kept upright, especially for those patients who usually have a compensated head position, pay more attention to this point. The mandible is neither adducted nor raised, so the doctor should facilitate the observation of the patient’s corneal reflection point. If the glasses affect the doctor's observation of the patient's corneal reflection point, you can slightly push the glasses up with your thumb, if necessary, you can take off the glasses, and insert a suitable lens into the lens slot of the synoptograph instead of the glasses.
