gms | German Medical Science

102. Jahrestagung der DOG

Deutsche Ophthalmologische Gesellschaft e. V.

23. bis 26.09.2004, Berlin

How does viscocanalostomy work? : a new concept to the mode of action using scanning electron microscopy

Meeting Abstract

  • corresponding author P. C. Ruokonen - Universitäts-Augenklinik, Charité, Campus RVK, Berlin
  • E. Robinson - Universitäts-Augenklinik, Charité, Campus RVK, Berlin
  • A. Sänger - Universitäts-Augenklinik, Charité, Campus RVK, Berlin
  • M. R. Tetz - Tagesklinik am Spreebogen, Berlin

Evidenzbasierte Medizin - Anspruch und Wirklichkeit. 102. Jahrestagung der Deutschen Ophthalmologischen Gesellschaft. Berlin, 23.-26.09.2004. Düsseldorf, Köln: German Medical Science; 2004. Doc04dogSO.02.05

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

Published: September 22, 2004

© 2004 Ruokonen 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.




Several studies have proven the efficacy of viscocanalostomy as a non-penetrating approach in glaucoma surgery. The mechanism responsible for the decrease in intraocular pressure has not been clarified in detail.

Patients and methods: From a pool of over 200 patients having undergone standardized viscocanalostomy performed by one surgeon 50 eyes were selected for this study. 25 eyes were defined as a long-term success, whereas in 25 eyes, a repeat operation was necessary. The resected deep scleral flap was investigated using scanning electron microscopy. Morphological findings were correlated with the clinical outcome.


In 45 scleral flaps (90%), tissue of Schlemm's canal was found. Absence of Schlemm's canal correlated with early postoperative failure (p<0.05). The amount of anterior trabecular meshwork correlated well with the long-term success (p<0.01). The number of septae in Schlemm's canal showed a significant coherence to the incidence of postoperative hypotony (p<0.001), whereas there was no correlation to the success rate.


Schlemm's canal was precisely deroofed in most of the cases. A deep sclerectomy without resection of anterior meshwork seems to have a lower effect on reduction of IOP. A microperforation of the inner wall of Schlemm's canal due to resection of septae leads to a higher risk of early postoperative hypotony, but has no influence on long-term results.