EXTIRPATION OF THE MEMBRANA NICTITANS 469 



upon the adjacent structures and thus develop into conditions 

 requiring interventions of greater magnitude, — ablation of 

 the eyeball, etc. - x 



Then finally there is deformity of the cartilage following 

 traumatisms. A serious inflammation of the membrane: 

 nictitans occasioned by violence may cause the cartilage to 

 crimp along the free border and thus press upon the globe 

 with harmful effect. 



TECHNIQUE. — The operation is best performed in the 

 recumbent position with -aid of local anaesthesia, induced with 

 cocaine ten per cent dropped into the field. Attempts to ex- 

 tirpate even portions of the organ in the standing position 

 often are unsatisfactory on account of the impossibility of 

 immobilizing the head. 



The eye is first disinfected with boric acid solution and 

 then anaesthetized with the cocaine solution. The latter is 

 given ample time to penetrate the mucous membrane. 



The lids are held apart with two stitches hitched into the 

 borders of each and the membrana nictitans is drawn out 

 with a third stitch hitched through its free edge. An assist- 

 ant holds the eye open with t-he two lid stitches and the oper- 

 ator draws upon the organ with the third one as it is dissected 

 loose with the scalpel or scissors. 



The best dissection to effect a rapid ablation of the mem- 

 brana nictitans is made as follows : The organ is drawn out- 

 ward with the stitch, and the mucous membrane which con- 

 nects it to the eyeball beneath is incised through and through 

 from above downward. Then after drawing it forward as far 

 as possible the incision is carried through .the mucous mem- 

 brane covering its external surface. A snip at each border 

 (superior and inferior) now liberates the cartilage so that it 

 can be torn out by traction, with the assistance of blunt dis- 

 section effected with the handle of the scalpel. If the car- 

 tilage resist avulsion the refractory attachments are snipped 

 here and there with the blade of the scalpel as the traction 

 continues. 



By employing this method bleeding will be nominal and 

 can easily be controlled by packing the cavity with gauze and 

 holding it in place by tying the lid stitches together. To facil- 

 itate removal of the gauze its end is left protruding from the 

 canthus. 



After two or three hours the lid stitches are untied and 

 removed and at the end of twenty-four hours the gauze is 

 withdrawn. 



Cicatrization follows without much reaction if asepsis is 



