348 On the Staphyloma, Hydrophthalmia, 



thecorne?; after which, the needle being cut o'S, a knot 

 should be tied in the thread, at the distance of about an 

 inch from the eye, to hinder it from slipping. This thread 

 IS more useful in cases where the eye is so much enlaroed 

 as nearly to fill the orbit, than when it is smaller ; the fm- 

 ger alone, in the former case, being insufficient to incline 

 the tumour from one side to the other, so as to make the- 

 room that is required for the proper use of the knife. If 

 the tumour be considerable, the upper and lower eyelids 

 should next be separated, by dividing with the knife the in- 

 teguments which unite them on the side next the temple. 

 This will give much additional room for the introdnctioa 

 of the knife to dissect the diseased organ from its attach- 

 ments. The conjunctiva should then be divided round the 

 whole globe of the eye; and afterwards the knife be carried 

 downwards, on that side where it passes with the greatest 

 ease. It is not possible to give precise directions, as to the 

 mode in which the dissection should be conducted; but 

 great care should be taken to avoid wounding the tumour 

 until the point of the instrument has reached the bottom of 

 the orbit. If it be possible, the operator should introduce 

 his finger with the knife so as to feel the optic nerve, which, 

 together with the muscles of the eye, should be divided as 

 close to the foramen opticum as the instrument can be car- 

 ried. In general the common straisiht scalpel may be so 

 directed as to perform this part of the operation with ac- 

 curacy ; but if the tumour completely fill the orbit, it may 

 be useful, in this part of the operation, to substitute for the 

 straight scalpel one that is a little curved. As soon as the 

 optic nerve and muscles of the eye have been divided, the 

 tumour becomes loose, and n)ay be easily drawn out of the 

 orbit, ei(her by the fingers, or by the ligature that was passed 

 through the cornea at the beginning of the operation. The 

 tumour, when removed, should be carefully examined, in 

 order to ascertain if it be entire, or if it be wounded in any 

 part.. In the latter case, the orbit should be carefully ex- 

 amined, both with the eye and the finger; and if any por- 

 tion of the tumour be seen or felt, it should be dissected 

 away. The state of the nerve should also be examined. If 

 this appear while, and of its natural size, a hope may be 

 entertained that the operation will prove successftd ; but if 

 ii appear of a leaden colour, or be altered in shape or size, 

 there is too ntuch reason to fear that the disease has passed 

 beyond the part which has been removed, and that, sooner 

 or later, a fungus will arjse in the orbit, aiid all the old sym- 



.ptonis 



