EYE COMPLICATIONS OF TROPICAL DISEASES 2007 



Quinine. 



Amaurosis associated with complete deafness may set in after 

 doses of less than i gramme of quinine, though more usually after 

 a dose of 3 grammes and upwards. The amaurosis gradually dis- 

 appears, leaving an amblyopia with a much contracted field of vision. 

 This result is due to a destruction of the ganglion cells of the retina 

 by the quinine, after which a degeneration of the optic nerve sets in. 



The symptoms are a blanching of the retina and disc, due to spasm 

 of the vessels, and loss of the pupillary light reflex, the pupils being 

 widely dilated. It should be differentiated from the malarial 

 amaurosis. In the former the pupils are usually widely dilated, 

 and do not react to light, while in the latter they do react to light. 



The deleterious effect of therapeutic doses of quinine has often been ex- 

 aggerated. Doses of 10 to 15 grains may usually be given three times daily 

 for long periods of time without any damage to the eyes. Jamieson and 

 Lindsay have noted that even when the visual field is found to be contracted, 

 the prognosis is good and ultimate expansion of the field may be expected. 



Atoxyi, 



Sudden amaurosis may be caused by atoxyi. 



Animal Parasites. 



Ocular Paragonimiasis. — Cysts containing P^f^x^owme^s -westermanni 

 have been reported as occurring on the eyelids and orbit, and so 

 hindering the movements of the eyeball and obstructing the vision. 



03ular Filariasis. — Loa loa has been noticed in the ocular and 

 palpebral conjunctiva {vide pp. 645 and 1972). 



In addition to paragonimiasis and filariasis, the following parasites 

 occur in the eye or its adnexa: Agamodistomum ophthalmohium 

 Diesing, 1850; Monostomum lentis von Nordmann, 1832 (both of 

 which may be stages of Dicroccelium lanceatum Stiles and Hassell, 

 1896); Sparganum mansoni Cobbold, 1883; Agamofilaria ociili 

 von Nordmann, 1832; Agamofilaria palpebralis Pace, 1867, 

 nec Wilson, 1844; Dermanyssus gallincB De Geer, 1778 (which may 

 be seen as a dark spot embedded in the cornea); Demodex follicu- 

 lorum Simon, 1842, which is found in the Meibomian glands, and 

 may cause a blepharitis. The larvae of Dermatohia cyaniventris 

 Macquart, 1843, has been found by Malgahaes under the palpebral 

 conjunctiva and in the lachrymal, sacs in Brazil. A larva of Sarco- 

 phaga magnifica Schiner, 1862, has been found in the anterior 

 chamber of the eye, and a larva of a species of Necrohia in a sclerotic 

 tumour ; but for afuller account of ocular myiasis seeChapter LXVII. 



Cysticercus celltdoscB has been found in the choroid, which it may 

 leave, and, passing under the retina, may cause detachment; later 

 it may perforate the retina and enter the vitreous, or it may enter 

 the retina or the ciliary region, and so pass directly into the vitreous, 

 where it appears as a bluish-white bladder, with or without a pro- 

 truded head. The eye may be destroyed by irido-cyclitis. Echino- 

 coccal invasion is very rare. 



