TY - JOUR
T1 - Improvement in outflow facility by two novel microinvasive glaucoma surgery implants
AU - Hays, Cassandra L.
AU - Gulati, Vikas
AU - Fan, Shan
AU - Samuelson, Thomas W.
AU - Ahmed, Iqbal Ike K
AU - Toris, Carol B.
PY - 2014
Y1 - 2014
N2 - Purpose. To determine improvement in outflow facility (C) in human anterior segments implanted with a novel Schlemm's canal scaffold or two trabecular micro-bypasses. Methods. Human anterior segments were isolated from 12 pairs of eyes from donors with no history of ocular disease and then perfused at 50, 40, 30, 20, and 10 mm Hg pressures for 10 minutes each. Baseline C was calculated from perfusion pressures and flow rates. The scaffold was implanted into Schlemm's canal of one anterior segment, and two micro-bypasses were implanted three clock-hours apart in the contralateral anterior segment. Outflow facility and resistance were compared at various standardized perfusion pressures and between each device. Results. Compared to baseline, C increased by 0.16 ± 0.12 μL/min/mm Hg (74%) with the scaffold, and 0.08 ± 0.12 μL/min/mm Hg (34%) with two micro-bypasses. The scaffold increased C at perfusion pressures of 50, 40, 30, and 20 mm Hg (P < 0.005). Two micro-bypasses increased C at a perfusion pressure of 40 mm Hg (P < 0.05). Conclusions. Both implants effectively increased C in human eyes ex vivo. The scaffold increased C by a greater percentage (73% vs. 34%) and at a greater range of perfusion pressures (20 to 50 mm Hg vs. 40 mm Hg) than the two micro-bypasses, suggesting that the 8-mm dilation of Schlemm's canal by the scaffold may have additional benefits in lowering the outflow resistance. The Hydrus Microstent scaffold may be an effective therapy for increasing outflow facility and thus reducing the IOP in patients with glaucoma.
AB - Purpose. To determine improvement in outflow facility (C) in human anterior segments implanted with a novel Schlemm's canal scaffold or two trabecular micro-bypasses. Methods. Human anterior segments were isolated from 12 pairs of eyes from donors with no history of ocular disease and then perfused at 50, 40, 30, 20, and 10 mm Hg pressures for 10 minutes each. Baseline C was calculated from perfusion pressures and flow rates. The scaffold was implanted into Schlemm's canal of one anterior segment, and two micro-bypasses were implanted three clock-hours apart in the contralateral anterior segment. Outflow facility and resistance were compared at various standardized perfusion pressures and between each device. Results. Compared to baseline, C increased by 0.16 ± 0.12 μL/min/mm Hg (74%) with the scaffold, and 0.08 ± 0.12 μL/min/mm Hg (34%) with two micro-bypasses. The scaffold increased C at perfusion pressures of 50, 40, 30, and 20 mm Hg (P < 0.005). Two micro-bypasses increased C at a perfusion pressure of 40 mm Hg (P < 0.05). Conclusions. Both implants effectively increased C in human eyes ex vivo. The scaffold increased C by a greater percentage (73% vs. 34%) and at a greater range of perfusion pressures (20 to 50 mm Hg vs. 40 mm Hg) than the two micro-bypasses, suggesting that the 8-mm dilation of Schlemm's canal by the scaffold may have additional benefits in lowering the outflow resistance. The Hydrus Microstent scaffold may be an effective therapy for increasing outflow facility and thus reducing the IOP in patients with glaucoma.
KW - Drainage device
KW - Glaucoma anterior segment
KW - Outflow facility
KW - Schlemm's canal
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U2 - 10.1167/iovs.13-13353
DO - 10.1167/iovs.13-13353
M3 - Article
C2 - 24550367
AN - SCOPUS:84897130319
VL - 55
SP - 1893
EP - 1900
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
SN - 0146-0404
IS - 3
ER -