Abstract
Purpose: :
To evaluate the effects of the Hydrus(TM) Aqueous Implant (Ivantis, Inc., Irvine CA), a nitinol device that opens the natural outflow pathway through two quadrants of Schlemm’s canal, on outflow facility in a human anterior segment perfusion model.
Methods: :
Human eyes were obtained from the National Disease Research Interchange within 48 hours of death. All donors were between 47 and 80 years of age and had no history of ocular disease or surgeries. The anterior segments were isolated and mounted on custom-made fixtures connected to a perfusion system. Baseline outflow facilities of all eyes were calculated from the slope of flow versus pressure by plotting the corresponding flow rates at four perfusion pressure levels (10, 20, 30, and 40 mmHg) assessed over 40 minutes. The Hydrus(TM) device was inserted in the experimental eyes (n = 9) while the control eyes (n = 6) underwent a sham procedure but no device insertion. The outflow facilities of all eyes were measured again. Control eyes and experimental eyes were compared by two-tailed unpaired t-tests. Baseline and second outflow facility measurements from the same eye were compared by two-tailed paired t-test.
Results: :
After device implantation in the experimental eyes, the outflow facility increased 95% (p<0.005) from its baseline of 0.24 ± 0.02 to 0.46 ± 0.07 uL/min/mmHg (mean ± SEM, n=9). The second outflow facility measurement of the control eyes did not change significantly from its baseline (0.24 ± 0.03 vs. 0.24 ± 0.04 uL/min/mmHg, n = 6, p = 0.77). There was no significant difference (p = 0.96) between the baseline outflow facility measurements of experimental and control eyes. However after the device was implanted, the experimental eyes had a significantly higher mean outflow facility measurement than the control eyes (p = 0.03).
Conclusions: :
The novel Hydrus(TM) Aqueous Implant provides an effective way to increase outflow facility in perfused ex vivo human eye anterior segments.
Keywords: outflow: trabecular meshwork • anterior chamber • anterior segment