Background: A new "ab externo" technique for glaucoma trabecular surgery creating multiple perforations of the trabeculum to improve outflow facility was tested.
Material and method: In order to perform a draining canal to the anterior chamber, a quartz fiber (phi: 300 microns) with a side-firing tip, coupled to an Er:YAG laser (2.94 microns), was inserted into Schlemm's canal of an enucleated human eye.
Results: Eight pulses of 8 mJ each were sufficient to perforate the trabecular meshwork. Histologic analysis showed a rippled canal with 50 microns average diameter and a surrounding necrosis zone of 15-35 microns.
Conclusions: The Er:YAG laser trabeculostomy, in conjunction with special fibers, shows promise as a new "ab externo" technique for minimally invasive therapy of open angle glaucoma.