2004 DISEASES OF THE ORGANS OF SPECIAL SENSE 



by means of a special hook introduced through the corneal wound 

 made for a cataract extraction and under the iris. After this pre- 

 liminary proceeding he completes the operation by intracapsular 

 extraction of the lens. 



Glaucoma. 



Acute glaucoma is rare in the tropics, while chronic glaucoma is 

 common; but the signs, symptoms, and treatment are the same as 

 in the Temperate Zone. The Elliot operation of trephining, with 

 or without subsequent iridectomy, is recommended. 



Fundus Oculi. 



The colour of the fundus oculi depends upon the amount of retinal 

 pigment present and to a less degree upon the amount of the 

 choroidal pigment visible. It therefore shows variations from the 

 European standard in dark and yellow races. In these races the 

 amount of retinal pigment is increased, and may completely conceal 

 that of the choroid, and so produce a uniform yellowish colour, as 

 seen in the Chinese; or a dark reddish, or even an almost greyish- 

 red colour, as seen in the various negro races. 



On the other hand, when the retinal and choroidal- pigments are 

 diminished, as in albinism; then the white sclerotic shows through, 

 and the fundus becomes of a lighter red colour than normal. 



Sunlight. 



The effect of sunlight on the eyes has been studied by Sisson, 

 who considers that there is ample proof that light injures the eye, 

 and that it may possibly be the cause of some diseases of the eye, 

 the aetiology of which is but little understood. Schmidt considers 

 that nyctalopia and hemeralopia may be caused by excessive light. 

 The use of protective xanthophylline glasses is recommended. 



B. EYE COMPLICATIOl^S OF TROPICAL DISEASES 

 Malaria. 



Malaria is held to be responsible for conjunctivitis, serpiginous 

 corneal ulcers, malarial iritis, and retino-choroiditis, as well as 

 amaurosis. 



Until a few years ago, the majority of the fevers of the tropics, 

 including enteric fever, were classified aS malaria, and any locil 

 affection of an unknown nature was also classified in the same 

 manner. The case of conjunctivitis in which one of us found cell 

 inclusions would a few years ago have been named malarial. We 

 are therefore of the opinion that the existence of malarial conjunc- 

 tivitis has not been proved. 



Keratitis Dendritica. — This keratitis is that variety of herpes 

 corneae febrilis (sometimes called ' herpes ccrnese zoster ') which 

 gives rise to those ulcers (formed from the ruptured herpetic 

 vesicles) which extend in certain directions only as grey forked 

 striae with lateral branches, which break down, thus forming a 



