The cure of strabismus by surgical operation ... / By William Mackenzie ; Being an appendix to the first, second, and third editions of his 'Practical treatise on the diseases of the eye'.

  • Mackenzie, William, 1791-1868.
Date:
1841
Catalogue details

Licence: Public Domain Mark

Credit: The cure of strabismus by surgical operation ... / By William Mackenzie ; Being an appendix to the first, second, and third editions of his 'Practical treatise on the diseases of the eye'. Source: Wellcome Collection.

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    § 14.— Orthophthalmic practice. Success in curing strabismus depends much on the patient’s persevering in well-directed practice. Three varieties of practice have been referred to in the preceding pages; viz. the parallel, the diverging, and the converging. 1. If, in any case, parallelism can be produced by covering the better eye, it ought to be bandaged, and the other eye exercised. If, by a con¬ tinuance of this parallel practice, the sight of the worse eye is made to equal that of the better, a permanent cure, without operation, will be the result. After an operation for strabismus, if the distortion relapses, is confined to the distorted eye, and is attributable merely to an effort made by its levator and depressor, parallel practice will be all that is required. The only effect, on the other hand, of bandaging one eye in cases of distortion involving both eyes, either before or after operation, is revers¬ ing the position of the eyes, so that the utmost to be gained by such a practice would be a permanent change of the inversion or eversion from the one to the other, by producing a change in their relative powers of vision. 2. If, after an operation on one adductor, there is any relapse, or renewal of the mutual convergence, as will be shown by inversion of the worse eye, the patient must employ Mr Elliot’s side-practice, or diverging practice. For instance, if the left eye was the worse, and its adductor only was divided, and there is a relapse, let the patient look to his right. By this plan, the inverting power of the left eye is no doubt increased, but the mutual convergence is diminished, and the relapse may be cured. If both adductors were divided, in a case where the left eye was the worse, and there is a relapse, the patient should look to his left, by which means divergence will be produced, as well as eversion of the worse eye. 3. If the case has been one of mutual divergent strabismus, and one or both abductors have been cut, the patient should avoid side-practice, and look at near and small objects, placed straight before him. This is con¬ verging practice, which is required also in cases of diplopia and eversion after division of one or both adductors. One of the best modes of using converging practice, is for the patient to look frequently at two reflected images, placed at the true concourse of the optic axes, as in Mr Wheat¬ stone’s ingenious instrument, called the stereoscope. § 15.— Ultimate good effects of the operation. The ultimate good effects of the operation refer to the mobility of the eye, and the state of vision. 1. In successful cases, the distortion is permanently removed, the eye occupies its natural position in the orbit, the axes of the two eyes are parallel when distant objects are regarded, and converge equally, and in the proper degree, when the object is near. The motion of the eye is free and uncontrolled. If the case was one of convergent strabismus, the eye does not rest in the centre of the orbit, as perhaps it did immediately