I have with interest watched the discussions of late, as to the
relative value of the Maddox or Stevens tests for heterophoria, as I
have for years used them both.
My muscle tests have been made for the last five years at least,
with a Risley phorometer, which combines both tests upon one arm and
has proven for me a most satisfactory instrument.
I am sorry to say that I have not kept any comparative statistics of
my examinations; at the same time they have all left an impression
upon my mind, which is this: that I feel more confidence in the
results obtained from the use of the Maddox test in the routine
tests that I always make of refractive cases. If this test shows any
marked degree of heterophoria it has been my habit to retest the
patient by the Stevens method, which is usually the same, provided
the patient has a sufficient amount of intelligence to give correct
answers to the questions put to him. During this test the patient is
allowed to sit for some time in front of the prisms, and the eye
muscles allowed to relax from that first impulse at muscular effort
that follows the placing of the prisms in front of the eyes.
To my mind both tests are good and fairly accurate in the hands of
one who is thoroughly familiar with their use and shortcomings,
provided your patient is able to answer correctly.
Many times, on re-examining a patient, I have discovered what
appeared to be a great change in the muscular conditions, but after
repeated examinations I have usually found it was the patient, and
not the muscles, that was erratic.
When Dr. Hubbell speaks of ¼° of difference between the Maddox and
Stevens tests, he has more confidence than I have in the average
judgment of patients that come under our care.