788 PEKCY FKIDENBEKG 



In these cases there was slight exophthalmos, with dilated pupils, insuf- 

 ficiency of convergence, and asthenopia with ciliary congestion and fatigue. 

 Chorioretinal changes, usually in the macular region, were not uncommon. 

 Many of the subjects show a lack of somatic as well as of ocular pigment, 

 and general symptoms of an overacting thyroid. 



Ocular Symptoms in Exophthalmic Goitre. The sympathetic irrita- 

 tion which attends this serious affection is expressed, vividly in a number 

 of characteristic states involving the pupil, the lids and lid-fissure, and the 

 position of the globe in the orbit, The lid-fissure is wider than usual, 

 owing partly to a lack of tone of the sphincter orbicularis palpebrarum 

 and increased action of the levator palpebrae superioris, and partly, 

 no doubt, to prominence of the eyeball itself. This may, in the initial 

 stages, be due to sympathetic irritation of the unstriped muscle fibers in 

 the orbit, but as will be noted later on, this factor alone fails to explain 

 the persistence of exophthalmos after extirpation of the u^yroid and even, 

 as noted by Schirmer, after death. Hypertrophy of the orbital fat, with 

 possible inflammatory changes resulting in the production of more or 

 less solid tissue, is undoubtedly the main cause. 



The characteristic expression of wide-eyed horror is due to this patho- 

 logical stare (Gilford's sign) which is accentuated by marked infrequency 

 of winking (Stellwag), lack of fixation convergence (Moebius) and, not 

 infrequently by the dilated pupil. 



Incoordination of the associated action of the levator with the ex- 

 trinsic ocular muscles is expressed by a lagging behind of the upper lid 

 when the eyes are made to fix an object above the horizontal and gradu- 

 ally move downward exposing an area of white, allowing the sclera to 

 appear above the upper margin of the cornea (Graefe's sign). 



Symptoms such as are usually found in hyperthyroidism have been 

 noted in cases of persistent thymus. Besides the typical symptoms, vari- 

 ous observers have reported alopecia and loss of eyebrows and lashes, 

 disturbances of lachrymal secretion, either as epiphora or as loss of tears, 

 and ocular bruit, synchronous with the pulse; cptic nerve atrophy and 

 neuritis. Tyson notes an increased stare, due to hypertonus of the levator, 

 on attempted convergence. 



Prominence of the globe in Basedow's disease and other hyperthyroidic 

 states was quite generally attributed to sympathetic irritation of the 

 unstriped muscle fibers in the orbit, in spite of the fact that the pro- 

 trusion was unaffected by pressure 011 the globe and persisted after 

 thyroidectomy and even after death (Schirmer). This spoke against 

 such a neurcmuscular theory and in favor of a mechanical ele- 

 ment. This was found in fat Hypertrophy of the orbit, with markedly 

 increased vascularity, and, at times, connective tissue hypertrophy. Thom- 

 son noted a conjunctival chemosis attending exophthalmos which had an 



