Comparison of the Remaining Time of OVD During Phacoemulsification in 2 Phacoemulsification Machines
Purpose
For the corneal endothelial protection, ophthalmic viscosurgical devices (OVDs) should remain in the anterior chamber during phacoemulsification (PEA). However, the water flow can affect OVD’s retention in the anterior chamber. We compared the retention of OVDs in 2 PEA machines with a different number of rotors in their peristaltic pump.
Methods
During PEA simulated in the porcine eyes, the remaining time of OVDs was measured in the anterior chamber which was filled with fluorescein stained OVDs, Healon V (AMO) or Provisc (Alcon). Five porcine eyes were used in each group. PEA was performed by the Centurion (Alcon) machine (CT group) or the Infiniti (Alcon) machine (IF group) with the following settings, US power, 0%; vacuum pressure, 600 mmHg; aspiration flow rate, 55 mL/minute; and intraocular pressure, 36 mmHg (bottle height of 50 cm). In addition, the effect of the higher intraocular pressure setting (55mmHg, bottle height 75cm) using Provisc was also examined.
Results
The retention time of Healon V was significantly longer in the CT group (mean; 32 sec) than in the IF group (mean; 10.4 sec, P<0.05). Similarly, Provisc retained significantly longer in the CT group than in the IF group (P<0.05). With the higher bottle height setting, however, retention of Provisc showed no significant difference in 2 machines.
Conclusion
The Centurion is superior to the Infiniti in retention of OVDs. The difference seems to be caused by the difference of their peristaltic pump structure. The water flow produced by the 7 rotors in the Centurion may be smoother than that of the 4 rotors in the Infiniti.