Muscular asthenopia and its treatment by graduated tenotomy / by Charles Hermon Thomas.

  • Thomas, Charles Hermon.
Date:
[1894]
Catalogue details

Licence: Public Domain Mark

Credit: Muscular asthenopia and its treatment by graduated tenotomy / by Charles Hermon Thomas. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

    8/12 (page 178)
    put. Symptoms aggravated by use of eyes for near work, interfering with regular duties. Has manifest Es. 12°-15°. Ordered prisms aggregating 10°, base out which were worn for a Aveek with comfort. Es. advanced meantime to 22°. Tenotomy, right internus, complete section, result, Es. 4°. A week later 12° was manifested with marked recovery from convergence under cover test. A second operation, left internus, section nlmost complete ; result, orthophoria when his sphero-cylinders are worn, though there is recovery from convergence, Es. 6°, when glasses ai'e removed. Reports entire comfort and ability to use his eyes to an unlimited amount. Considerable discussion has taken place as to the relative frequency of esophoria and exophoria, and different writers have asserted a marked preponderance on either side. A review of my cases for the last nine years shows that in the operative cases, as between esophoria and exophoria, these are almost exactly equally divided; and while there has been a certain variation on one side or the other from year to year, a close parallelism has been maintained in the main through- out the whole period. This examination also shows, as regards the refraction in both these forms of heterophoria, that hyper- metropia predominated. The predominance of hypermetropia was more marked in the cases of esophoria than in those of exophoria, as the following figures show:— In esophoria the relative frequency of H. over M. was in the proportion of 3f to 1; in exophoria the relation of H. to M. was as 2J to 1. Thus, while the most of the cases of hete- rophoria show hyperopic refraction—as is to be expected con- sidering the greater frequency of this condition over myopia ; when the static refraction is viewed in its relation to the accompanying heterophoria, we find that hypermetropia is usually accompanied by esophoria and myopia is most fre- quently associated with exophoria. There is still to be found occasionally one who maintains the opinion that a complete tenotomy is required in every case of heterophoria calling for operation, on the assumption that no gain whatever is to be derived from partial severance of the tendon. My experience leads me to a directly opposite conclusion.