Intraocular Pressure Control Using A Novel Phacoemulsification Device

To demonstrate intraocular pressure (IOP) control using UNITY VCS during cataract surgery based on initial clinical experience and bench testing.

Outpatient clinical study and bench-top experimental study 

A prospective single-arm clinical study evaluated the safety and performance of the UNITY VCS in adults presenting for routine cataract surgery. In addition, bench testing using an eye model and calibrated pressure sensor measured IOP control error by evaluating the pressure difference between the IOP setpoint and the measured IOP during aspiration flow (for 10 seconds) after reaching steady state (5 seconds after aspiration is initiated). To test the system at its limits, 30 phacoemulsification handpieces were tested at 20-120 mmHg IOP and 15-60 cc/min aspiration flow rate and 15 I/A handpieces were tested at 20-120 mmHg IOP and 15-30 cc/min aspiration flow rate.

50 subjects underwent cataract surgery using UNITY VCS with exceptional anterior chamber stability observed during all cases. This is supported by results from the bench where the highest expected IOP control error at the lowest/most physiological IOP (20 mmHg) and highest aspiration flow rate was 2.36 ± 2.13 at 60 cc/min and 4.19 ± 1.97mmHg at 30 cc/min during phacoemulsification and I/A, respectively. These results compare favorably to physiologic IOP diurnal variation in normal patients (5.0 ± 2.7mmHg) and demonstrate that IOP would be expected to be maintained approximately within 18 to 22 mmHg when the IOP is set to 20 mmHg during the phacoemulsification step.

UNITY VCS demonstrates excellent IOP control during cataract surgery as observed clinically and on the bench. Maintaining IOP at the desired surgeon setpoint with minimal fluctuation throughout surgery may reduce intraoperative and postoperative complications, especially in more complex cases.