FREE BOOKS

Author's List




PREV.   NEXT  
|<   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62   63   64   >>  
a of the comparative value of the three methods that comprise the great majority of interventions made use of by ophthalmic surgeons at the present time. I refer to _iridectomy_, the _Lagrange operation_, and the _Elliot operation_. So far as regards the last named procedure, I congratulate this Society that it has had an opportunity of seeing a demonstration and hearing a discussion by the famous ophthalmic surgeon who perfected it. As regards the others let me recommend to you the complete description of them given by Posey in _A System of Ophthalmic Operations_. Let us consider the first of the three procedures just mentioned--_iridectomy_--introduced by von Graefe. The mechanism of its mode of cure is best studied in cases of acute primary glaucoma, when there is apposition of the periphery of the iris to the cornea. In these acute cases there is probably only a mere _apposition_, and the blocking up of the sclero-iridian angle is largely mechanical. Here the root of the iris is readily removed in its entirety and a really peripheral iridectomy is easily done. When, however, a true _adhesion_ between corneal and iridic tissue takes place the filtration angle is not so easily opened. True peripheral adhesions are not readily broken up or separated, and the iridectomy is, for that reason at least, not effective. Moreover, this form of anterior synechia (resulting from a true union of iris and cornea) is so intimate that the iris root is, by the iridectomy, torn away only at the sclero-iridian angle at the anterior border of the adhesion--and does not open up a channel into Schlemm's canal. It is not, therefore, difficult to understand why iridectomy alone in any of the forms of chronic glaucoma fails to open up the true filtration spaces and does not provide a drain that permits of an escape of fluid from the posterior chamber through the loose tissue that surrounds it into the canal of Schlemm. Treacher Collins found, after a careful examination of eyes upon which iridectomy had been performed for glaucoma, that it is extremely rare for the initial section to pass through the pectinate ligament, while Schlemm's canal invariably escapes. Moreover, since the sclero-corneal incision is uniformly oblique, the position and extent of the external wound does not always furnish evidence of the character of the internal wound. In all likelihood many cases of relief or cure following iridectomy are those due to the formatio
PREV.   NEXT  
|<   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62   63   64   >>  



Top keywords:

iridectomy

 

Schlemm

 
sclero
 

glaucoma

 

iridian

 

cornea

 

apposition

 

corneal

 

anterior

 

Moreover


easily
 

peripheral

 

adhesion

 

filtration

 

tissue

 

readily

 

operation

 

ophthalmic

 

relief

 

understand


difficult

 

chronic

 

posterior

 

escape

 

permits

 

spaces

 

provide

 

methods

 

intimate

 
resulting

synechia

 
formatio
 

comprise

 

channel

 

majority

 

border

 

interventions

 

chamber

 

incision

 

uniformly


escapes

 

invariably

 

pectinate

 

ligament

 

oblique

 

position

 

evidence

 
character
 

internal

 

furnish