Abstract
Abstract: :
Purpose: To determine what effect bypassing the trabecular meshwork has on outflow facility in cultured human anterior segments. Methods: Anterior segments from 9 donors (n=16 eyes) were placed in perfusion culture without the ciliary body. After establishment of baseline intraocular pressure, trabecular bypass stents were inserted into the trabecular meshwork with the lumen of the tube opening into Schlemm’s canal. Eyes were returned to culture, and intraocular pressure recorded. Eyes received from 1 to 4 stents, placed equidistant apart at 3, 6, 9 or 12 o’clock. In eyes receiving 1 or 2 stents, additional stents were later added to a maximum of 4 per eye. In 3 eyes, trabecular meshworks were excised and differences in intraocular pressure compared, (trabecular meshwork plus stents vs. removal of trabecular meshwork and stents). Control eyes were manipulated in a similar fashion each time a stent was placed in the experimental eye. Results:Facility of outflow increased after stent placement: 1 stent: increase 43% (n=2); 2 stents: increase 57% (p=0.04; n=6); 3 stents: increase 69% (p=0.02; n=4); 4 stents increase 41% (p=0.009; n=9). In two eyes, addition of 3 stents lowered IOP from 17 to 11.5 mmHg and following trabecular meshwork removal, intraocular pressure was reduced to 4.5 mmHg. In a third eye, stent placement in each quadrant, lowered intraocular pressure from 17 to 12 mmHg and maintained an intraocular pressure of 12 mmHg following trabecular meshwork removal. Conclusions: Bypass of the trabecular meshwork increases outflow facility in cultured human anterior segments.
Keywords: trabecular meshwork • anterior segment • outflow: trabecular meshwork