790 PERCY FRIDENBERG 



cut off. The resulting clinical pictures depend, of course and mainly, 

 on whether the hormone privation took place before or after the inception, 

 or, again, the completion of various developmental and nutritional proc- 

 esses. The best known forms are the thyroid and parathyroid priva- 

 tions (myxedema and tetany), the congenital athyreoses (cretinism, Mon- 

 golian idiocv) in all of which about the same ophthalmic signs of hor- 

 mone lack have been observed. 



Thyroid extirpation has been followed by grave degenerative changes in 

 the cornea which became porcelain white and densely opaque. Leber 

 ascribes the disturbance of nutrition to toxic endothelial necrosis. Hal- 

 sted noted severe conjunctival reaction, and various observers have called 

 attention to neuroretinitis, papilledema, or partial blindness without 

 ophthalmoscopic findings. Parathyroid extirpation, similarly, results in 

 a grave disturbance of calcium metabolism, resulting in acidotic or vago- 

 tonic activation of muscle tissue (spasmophilia) which is reflected in 

 clinical ophthalmology in the form of ciliary muscle spasm and hyper- 

 secretion of tears (Falta, Kahn). 



Myxedema. Edema of the lids, with a resulting narrowing of the 

 palpebral fissure, marginal blepharitis with sparse and brittle brow-hairs 

 and cilia. The oculocardiac reflex of Dagnini-Aschner is generally greatly 

 intensified, showing a marked vagotonia. 



Mongolian Idiocy. This peculiar type of congenital dyscrinism is 

 strikingly hereditary but familial grouping icannot always be shown 

 as far as the ocular defects are concerned. Besides the characteristic and 

 striking Mongolian fold or epicanthus, there is a marked upward and 

 outward slant of the lid-fissure in most of the cases, adding to the Chinese 

 appearance (Casey Wood). Blepharitis and ectropion, as well as nystag- 

 mus have been noted, with strabismus and hyperopic refraction. Cataract 

 of {he punctate variety is the most frequent ocular affection. There are 

 no characteristic vitreous or fundus changes. 



Tetany. Cachexia-thyreopriva is associated with but one charac- 

 teristic ocular disturbance, the formation of cataract. A relation to spas- 

 mophilia, as in all forms of lenticular degeneration, is obvious, as is 

 the factor of disturbance of calcium metabolism which plays. an important 

 role in other functional and developmental disturbances of the eye in 

 other hormone and vitamin privations. 



Hormone Deficiencies and Ocular Affections. Parathyroid Privation. 

 The spastic inhibition of nutrition becomes evident as interstitial kera- 

 titis and degenerative cataract which Coats brings into direct relation 

 with convulsions, epilepsy, and zonular cataract in similar states. The 

 lens changes in parathyroid privation are analogous to those in the teeth 

 which, as is well known, show diminished calcification of dentine, diminu- 

 tion of bone salts, and hyperplasia of the enamel. 



