Eyestrain (commonly called asthenopia) / by Ernest Clarke.

  • Ernest Clarke
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Eyestrain (commonly called asthenopia) / by Ernest Clarke. Source: Wellcome Collection.

    153/184 page 141
    He operates under cocaine in a dark room. A candle is placed twenty feet from the operating chair, and a focus of light is thrown by an assistant on the eye. He first makes a sma 1 hole the ten- don of the muscle, and judges of the amount of fibres to cut by constant examination of the position of the eyes by placmg before them a prism to produce diplopia. He says, Fibre after ^bre s thus cut until one candle comes over the other, or they are brought upon a level, as we require. He advises that the operation should only be done for heterophoria if there are symptoms of asthenopia, which symptoms may be present with half a degree of m- sufficiency of the internal recti in one person, while eight or ten degrees in another will not be noticed. He further advises that other means should be resorted to before trying tenotomy, but unnecessary delays should be avoided. ^ Burnett says: If tenotomy will restore the lost equi- librium of the muscles it is certainly the most scientific, the readiest, and in every way, the most commendable method of dealing with the difficulty. My own experience with the operation is somewhat limited, but could have been greater had I been less conservative and cautious. The results, however, have been eminently satisfactory and such as to convince me that not only is it a legitimate operation, but one that, under certain circumstances, is imperatively demanded ; and he proceeds to give detailed notes of five cases where a partial tenotomy was successful. 2 Stevens says,^ The treatment of hyperphoria is teno- tomy. The surgeon must choose between operating on the superior rectus of one eye, or the inferior rectus of the ' American Journal of Oph., vol. vii., p. 34. 2 Irans. Am. Oph. Soc, vol. vi., p. 221.
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