Dear Dr. Deady: In reply to your favor requesting my opinion regarding the respective merits of the Maddox rod and the diplopia test, I wish to say that my experience leads me to rely more and more upon the obscuration test, and while I have not followed out the comparison to any great extent, such as is shown by your tables, results obtained by relying upon the rod test in the detection of heterophoria, as well as in determining when the weak muscles have been sufficiently developed, have been such as to warrant my continuance of its use.
E. D. Brooks.
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.
Sayer Hasbrouck.
Dear Doctor: Your note asking my opinion of the comparative usefulness of the Maddox rod and the phorometer is at hand.