A case of mistaken musclesBMJ 2002; 325 doi: https://doi.org/10.1136/bmj.325.7358.282 (Published 03 August 2002) Cite this as: BMJ 2002;325:282
Superior oblique acting in isolation turns eye down and out
- Robert H Whitaker (email@example.com), assistant clinical anatomist
- Department of Anatomy, University of Cambridge, Cambridge CB2 3DY
- Western General Hospital, Edinburgh EH4 2XU
- University Hospital of Wales, Cardiff CF14 4XW
- School of Life Sciences, Kingston University, Surrey KT1 2EE
- Royal Free and University College Medical School, London WC1E 6HX
EDITOR—It was with a sense of déjà vu that I read the short piece about eye muscles.1 Among students and teaching staff in the department of anatomy in Cambridge we have argued this among ourselves on numerous occasions.
Our final conclusions, and what is now our policy for instruction on this muscle, is as follows. The superior oblique, acting in isolation, turns the eye down and out. However, if it was tested clinically by the patient being asked to look down and out, its action could be mimicked by the combined action of inferior and lateral recti. This is particularly so as the inferior rectus acts most effectively when the eye is abducted (looking laterally). Thus if the patient is asked to look down and in, these muscles are excluded and the problem is solved. Essentially we are testing the ability of the superior oblique to look downwards.
The confusion, which I hope the above clarifies, is compounded by some ophthalmologists being so used to testing the muscle …