Interpretation of results
NOTE! To get an overall picture and to make an accurate diagnosis KMScreen test should be seen as one of several tests that measures eye abnormalities.
In order to interpret the survey results, you must have the following four questions in mind:
1. What type of strabismus, has the patient?
Is it a vertical strabismus, horizontal, or a combination strabismus in which there is both vertical and horizontal strabismus?
2. Is the squint paralytic or non-paralytic, and is there a mechanical obstruction in one or both eyes?
3. Is there A or V phenomenon?
4. Is there torsion (tilt)?
3. Is there A or V phenomenon?
To answer question 3
In order to examine whether there is A or V phenomenon, comparing the angle measurements in four blocks of the display section.
Here, the following rule applies:
Patients with eso strabismus:
If the angle of gaze upward is ≥10 diopters than gaze downward, the patient has A-phenomenon.
If the angle of gaze upward is ≤10 diopters than gaze downward, the patient has V-phenomenon.
Patients with exo strabismus:
If the angle of gaze upward is ≥15 diopters than gaze downward, the patient has V-phenomenon.
If the angle of gaze upward is ≤15 diopters than gaze downward, the patient has A-phenomenon.
1. What type of strabismus, has the patient?
Is it a vertical strabismus, horizontal, or a combination strabismus in which there is both vertical and horizontal strabismus?
To answer question 1
Because the test is based on foveolär projection, begin by checking the primary focal point of each flag (called pp, primary position). The deviation in PP straight ahead usually indicate what type of strabismus patient.
Continue to check the "flags" position, which in turn indicates the position of the eyes.
Is the "flags" offset in primary position is vertical, put the focus on the vertical muscles. Is the flags mostly horizontally displaced, focusing on the horizontal muscles.
2. Is the squint paralytic or non-paralytic, and is there a mechanical obstruction in one or both eyes?
To answer question 2
Once you have an idea of what type of strabismus patient, proceed to the next step.
The next step is to find out if the squint is paralytic or non-paralytic. This is done by comparing the flags size, and compare the computer area calculations of flags outer border between the right and left eye. The surfaces calculations appear directly below each eye flag. 100% means normal eye movements, more than 100% means that we have the overcapabilities of eye movements. Less than 100% means that there are restrictions on the eye's movement.
If the difference between the "flags" is large (more than 3%), there may be signs of paress because the paralytic eye flag is always smaller (this is due to Hering's law). This is called a inconcomittant strabismus. Then focus on the paralytic eye (the eye that has the smallest flag).
If the flags seem to be equal, and the calculations for both eyes externa area confirm this, then we called a concomittant strabismus. Concomittant strabismus is due to the symmetrical limitation of eye movement, and is usually due to a non-paralytic strabismus. But there are exceptions. If the squint has been around for many years, the restriction of movement from the paralytic eye has "spread" to the non-paralytic eye, and then we can get a symmetrical movement limitation on both eyes.
Continue to compare the area between each eye's outer and inner flag. If there is a big difference between the two calculations, it may be a sign of some kind of mechanical obstruction of the eye movement. For example, patients with Duan syndrome have almost 100% in the inner area while considerably smaller percentage flag in the external flag in the same eye. The same is true for patients with so-called blow-out fracture. Sometimes this can be observed even in patients who have been operated for strabismus.
Once it is found that the squint is inconcomittant continue diagnosis to possibly find one or more paralytic muscles. This is done by looking at the eye that has the smallest flag and the gaze direction of the flag where there is greatest underfunktion. Note If the squint is vertical, put the focus on the four vertical muscles. If the squint is horizontal, put the focus on the two horizontal muscles.
In ocular motility chart you can see which muscle has the most underfunktion and overfunktion in degrees. This helps when you want to obtain the greatest underfunktion. In the gaze direction with the largest underfunktion there we can find the paralytic muscle and gives the diagnosis.
For example, it has been found that the patient has a vertical strabismus, and it's right eye with the smallest flag, while the main underfunktion (-) is in the downward nasally direction, it means that the diagnosis is right-sided trocklearis palpsy.
