gms | German Medical Science

102. Jahrestagung der DOG

Deutsche Ophthalmologische Gesellschaft e. V.

23. bis 26.09.2004, Berlin

Morphological changes of pig corneas after the use of preservatives in an in-vitro cornea penetration model

Meeting Abstract

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  • corresponding author B. Jakopp - Novartis Pharma AG, Ophtha Technical Development, Basel, Schweiz, Universitäts-Augenklinik Basel, Schweiz
  • C. Schoch - Novartis Pharma AG, Ophtha Technical Development, Basel, Schweiz
  • P. Meyer - Universitäts-Augenklinik Basel, Schweiz

Evidenzbasierte Medizin - Anspruch und Wirklichkeit. 102. Jahrestagung der Deutschen Ophthalmologischen Gesellschaft. Berlin, 23.-26.09.2004. Düsseldorf, Köln: German Medical Science; 2004. Doc04dogP 060

The electronic version of this article is the complete one and can be found online at:

Published: September 22, 2004

© 2004 Jakopp et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




With a cornea penetration model using pig eyes, the morphological effect of preservatives on the corneal parenchyma was examined. The goal of this study was to establish this in vitro method.


Freshly obtained pig corneas were fixed with an O -ring in an Frantz-type-diffusion system. Under physiological conditions (Tears buffer, Aqueous humor buffer, 37°C) the test-solution was applied to the epithelial side (donor chamber) and could now diffuse to the endothelial side (acceptor chamber). Preservatives, such as Benzalkonium chloride (BAC) with a concentration of 0,02 %, Cetrimide 0,02 %, Benzoxonium chloride 0,02 %, and others were tested. They were kept in contact with the cornea for up to 300 minutes. After different contact times (30, 60, 120, 180, 240, 300 minutes) the corneas were sampled and immersed into formalin solution for histological analysis. The pig corneas were rated with a histological score as following: epithelial edema, graduation I - IV, stromal edema, graduation I-II and the condition of the corneal endothelium (intact or damaged).


There was a clear correlation of corneal damage in function of incubation time. The increase in epithelial edema and in stromal edema could be demonstrated for the preservatives in varying degree. BAC showed by far the most pronounced effect on corneal parenchyma. Control eyes incubated with buffer only, did not exhibit these changes. A damaged corneal endothelium was used as a exclusion criterion.


This in vitro model offers the possibility to test and quantify the potentially toxic effects of ophthalmic excipients or complex solutions in a rapid way. Additionally it helps reducing in vivo experiments with rabbits.