Abstract
Purpose: :
This study compares changes in outflow facility of novel glaucoma devices in an ex vivo model of perfused human anterior segments.
Methods: :
Human eyes with no history of ocular problems were studied within 48 hours of death. Anterior segments were mounted on fixtures connected to a perfusion system. Baseline measurements of outflow facility were followed by measurements after device implantation or sham procedure. Statistical tests were paired and unpaired two-tailed t-tests. Implants studied were 8mm and 15 mm intracanalicular scaffolds (Hydrus™ Aqueous Implant, Ivantis, Irvine, CA) and trabecular micro-bypass stents (iStent® Glaukos, Laguna Hills, CA). Eyes with one 8 mm Hydrus Implant were compared with paired controls and with eyes containing two iStent implants.
Conclusions: :
Outflow facility increased by 72 and 90% with the 8 mm Hydrus Implant, 92% with the 15 mm Hydrus Implant and 36% with two iStent implants. Bypassing the trabecular meshwork and scaffolding Schlemm’s canal allows fluid to flow directly into collector channels thus reducing outflow resistance and decreasing intraocular pressure. While the Hydrus Aqueous Implant showed a greater percent increase in outflow facility than two iStent Implants, both provide effective ways to increase outflow facility in human eyes ex vivo.
Keywords: trabecular meshwork • anterior chamber • intraocular pressure