Bench Evaluation of Intraocular Pressure Control with Clinical Assessment of Anterior Chamber Stability of a Dual Peristaltic Phacoemulsification Device

John Berdahl,1 Daniel Terveen,1 Ali Aboughaida,2 David William Dyk,2 Satish Yalamanchili,2 Sarah Makari,2 Vance Thompson1 1Vance Thompson Vision, Sioux Falls, SD, USA; 2Research & Development, Alcon Research LLC, Fort Worth, TX, USACorrespondence: John Berdahl, Vance Thompson Vision, 3101 W 57th S.t, Sioux Falls, SD, 57108, USA, Email [email protected]: To demonstrate intraocular pressure (IOP) control using the UNITY® Vitreoretinal Cataract System (UVCS) during cataract surgery based on bench testing and initial clinical experience.Patients and Methods: 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 under continuous irrigation for approximately 10 seconds followed by aspiration for approximately 15 seconds. To examine the system at its limits, 30 phacoemulsification (phaco) handpieces were tested at 20 mmHg IOP and 60 cc/min aspiration flow rate, and 15 irrigation/aspiration (I/A) handpieces were tested at 20 mmHg IOP and 30 cc/min aspiration flow rate. In addition, a prospective, single-arm clinical study evaluated the safety and performance of UVCS in adults presenting for routine cataract surgery (clinicaltrials.gov, NCT06071104, Registered October 2, 2023).Results: The expected IOP variation at an IOP setpoint of 20 mmHg was 2.36 ± 2.13 at an aspiration flow rate of 60 cc/min during phaco and 4.19 ± 1.97 mmHg at an aspiration flow rate of 30 cc/min during I/A. These results compare favorably to physiologic IOP diurnal variation in normal patients (5.0 ± 2.7 mmHg) 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. This is supported by results from the clinical study where 68 subjects underwent cataract surgery using UVCS, with exceptional anterior chamber stability observed during all cases.Conclusion: UNITY VCS/CS demonstrates excellent IOP control in bench testing and was reported to provide exceptional AC stability clinically. Maintaining IOP at the desired surgeon setpoint with minimal fluctuation throughout surgery may reduce intraoperative and postoperative complications, especially in more complex cases.Keywords: cataract surgery, anterior chamber stability, irrigation, aspiration, UNITY Vitreoretinal Cataract System