Page:Handbook of Ophthalmology (3rd edition).djvu/551

 AMAUROSIS SIMULATA. 546 cases is at first wholly negative. Later, atrophic degeneration of the optic nerve may develop.* The occurrence of reflex amauroses is also asserted, and is referred to the irritation of dental nerves in carious teeth. f Ac- cording to Hutchinson,! these reflex effects may occur when the carious teeth are not painful. The hypodermic injection of strychnine in all forms of ambly- opia has lately been recommended. § I have seen a number of cases improve under this treatment, just as might happen with any treatment, or without any treatment whatever ; but the ma- jority of the absolutely negative results is so great that I have not been able to satisfy myself of the action of strychnine upon the optic nerve. I have never seen such immediate improvement of vision after the injection of strychnine as is asserted by Nagel to occur. Here is the place to discuss the methods for detecting simulated amblyopia. If, as is generally the case, absolute amaurosis on one side be simulated, the best and shortest method is that proposed by Von Graefe.ll Only the healthy eye is experimented with, and a prism of from 6° to 12°, with its base turned upward or down- ward, is placed before it. If now a candle flame or a dot or fine line upon a white paper be seen double, the simulation is at once proved, and at the same time the degree of vision in the pretended blind eye can be determined with sufficient exactness. As a fur- ther confirmation, it may be tried whether the double image moves during rotation of the prism, or whether the diplopia disappears upon the re-establishment of binocular single vision when the base of the prism is turned outward. It sometimes happens that the simulators deny the diplopia, t Wecker, Klin. Monatsbl., 1865, pag. 269 ; Alexander, ibid., 1868, pag. 42. X Oplith. Hosp. Kep., iv. 4, pag. 381. § Fremineau, Gaz. des Hop., 49, 1863; Siimann, Deutsche Klinik, 1864, No. 44 und 45; Talko, Klin. Monatsbl. f. Augenheilk., 1868, pag. 79, und 1869, pag. 145; Nagel, Die Behandlung der Amaurosen mit Strychnin, Tubingen, 1871. II Arch. f. Ophth., B. ii. 1, pag. 266.
 * Testelin, Klin. Monatsbl., 1865, pag. 358.