The “Becherer Twist” – How Will Your Patient
Perform in a Soft Toric Contact Lens? So, what do you know about the “Becherer Twist”?
No… its not a new dance! This quick test is an oldie but goodie, and can go a long
way in saving you chair time. Let me explain.
We have all been in a situation where our toric lens fits morph into multiple visits
and multiple trial options. So much effort is put into the process only to find out that
this particular patient is a poor candidate or is just going to have to deal with some
lens limitations. The “Becherer Twist” is a quick test that
will help you determine the patients prognosis for a good fit right from the start.
Here is what you do. 1. Instruct the patient that you are going
to make some adjustments and that this is going to help determine if they are suited
for soft toric contact lenses. 2. Display the full acuity chart
3. Keep the final prescription in the phoropter. 4. Tell the patient to indicate as soon as
they notice blur. 5. Slowly twist the axis dial clockwise – Stop
when they tell you. 6. Rotate the cylinder axis counterclockwise
– Stop when they tell you. So what information did we get from this exercise?
The amount of rotation the patient can tolerate tells you how sensitive they are going to
be to axis alignment. In other words, how easy or difficult this patient is going to
be able to please in a soft toric contact lens.
If the patient allows you to get out 15-20 degrees then you are smooth sailing. If you
are only getting out to about 5 degrees, that patient is going to need a much more accurate
axis alignment for a successful fit and education on realistic expectations.
Obviously, patient sensitivity has a lot to do with lens power. The higher the cylinder,
the more sensitive any patient will be to small adjustments. In some instances we might
have to explore additional lens options like rigid lenses, mini-sclerals, hybrids etc….
but that’s a whole different topic. The point is that the “Becherer Twist” literally
takes 15 seconds and can cut weeks of unnecessary follow-ups out of your appointment book. Give
it a try! Happy prescribing References:
Becherer PD. Toric lenses then and now: some timeless pearls. Eye Quest: 14-18. Oct 1991.