Insufficiencies of the oblique muscles and how to correct them / by G.C. Savage.

  • Savage, G. C. (Giles Christopher), 1854-1930.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Insufficiencies of the oblique muscles and how to correct them / by G.C. Savage. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    “ In my investigations I have always considered the eye before which no prism is held as the one under test. With the double prism before the right eye the patient is asked about the position and the direction of the middle line. It may be nearer the bottom, thus showing left hyperphoria; or again, it may extend farther to the right than the other two and not so far to the left, thus showing exophoria, or vice versa, showing esophoria. “If the right ends of the middle and bottom lines converge while the left ends diverge, the superior oblique of the left eye is at once shown to be in a state of underaction. Fig. 1 repre- sents such a test of the left eye. Fig. 2 shows a test of the left eye when the inferior oblique is the too weak muscle. Fig. 3 represents a test of the right eye, the loss of the parallelism between the lines being due to underaction of its superior oblique, and Fig. 4 the same condition of the inferior oblique of the right eye. Fig. 5 represents a test of both eyes when there is perfect equilibrium of the oblique muscles. “As is well known, the function of the oblique muscles is to keep the naturally vertical meridians of the two corneae parallel even when not vertical, [except in cases of uncorrected oblique astigmatism, as shown in Vol. 1, No. 1 of the Ophthalmic Record]. This must be, or a troublesome form of double vision will result. If there is perfect equilibrium of the obliques, this parallelism of the meridians named is maintained without trouble; but if the superior oblique of either eye be too strong for its inferior, or vice versa, the parallelism of the vertical meridians is pre- served, and double vision prevented, only by excessive work on the part of the weaker muscle. This condition of the oblique muscles brings on, at longer or shorter intervals, a train of nervous symptoms for which, at present, I can see no hope of prevention or cure.” As can be readily seen the condition described then was symmetrical insufficiency of the obliques. Up to that time I had not seen, nor had I heard of, a case of non-symmetrical insuffici- ency of the obliques. Dr. Moulton, however, reported such a case in a letter* to the *See Ophthalmic Record, Vol. i, No. 4, 1891.