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Abstract #19188 Published in IGR 3-1
The sartorial specter of viscocanalostomy
Van Buskirk EMJournal of Glaucoma 2001; 10: 1-3
In this editorial, the editor discusses what he calls a hot, new glaucoma procedure: viscocanalostomy. He states that, thus far, the presentation of viscocanalostomy verges more toward a pejorative metaphor of our time than an attractive alternative for glaucoma care. The unevaluated procedure has already been incorporated as a new technology in the practices of many anterior segment surgeons. To date, few papers have been published on the procedure, and many of them present pilot data calling for more studies. In an earlier editorial, Krieglstein pleaded for a more vigorously controlled investigation. Ironically, many of the virtues now promulgated for viscocanalostomy were originally advocated for trabeculectomy. In the 1970s, it slowly became clear that successful trabeculectomies were associated with filtration blebs. Viscocanalostomy may well go the same way. So far, we do not have valid information on the procedure. The mechanism of action is completely unclear. It comes as no surprise to anyone familiar with aqueous humor dynamics that, if you inject clear media into the severed end of Schlemm's canal, this will dilate and the aqueous veins blanche. This observation neither confirms nor refutes the hypothesis that the procedure achieves lasting continuity from the anterior chamber through Schlemm's canal to the aqueous veins. Johnson and Johnson suggest that canalicular dilation is simply another means of fistular filtration. Krieglstein showed that the canal was not even unroofed in nearly half the cases and that, in a third of the others, trabecular excision had been performed. This editor did work in the early 1980s showing that there is a highly dynamic and variable relationship between the trabecular meshwork and the walls of Schlemm's canal. Despite the obvious mechanical distensibility of the luminal architecture, nothing has coming to light in the last 26 years which would suggest that opening the canal in 2001 would have a more lasting salutary effect on aqueous outflow than it did in 1975. The editor also repeats that mere normalization of pressure may often be insufficient to prevent optic nerve progression. He concludes, as others have concluded before him, that, until published peer-reviewed data prove it to the contrary, viscocanalostomy would seem to be a nice parade but the emperor still looks naked.
Classification:
12.8.3 Non-perforating (Part of: 12 Surgical treatment > 12.8 Filtering surgery)