Computational Fluid Dynamics Simulation of Human Eye Anterior Chamber Fluidics During Regular and Microcoaxial Phacoemulsification
Narrative Responses:
Purpose
Simulated Steady state CFD analysis is done while performing the coaxial Phaco surgical Procedure through 1.8mm, 2.2mm and 2.8mm clear corneal incision sizes. Comparison is done on the fluid flow pattern under the three different incisions taking into consideration of the primary and side port wound leakages with thermal effects.
Methods
The irrigation fluid flow pattern through infusion sleeves is modeled, simulated, and analyzed using the Fluent - version 14.0 software. The Phaco incision sizes of 1.8, 2.2 and 2.8mm were considered. The parameters like Anterior Chamber fluidics, positive pressure, fluid turbulence, flow velocity, and temperature interference of the vibrating Phaco needle were compared and calculated within the Human Eye Anterior Chamber as an enclosed fluid domain by applying K - Epsilion turbulent model. At different stages of the Phaco surgery the surgical fluid turnover were compared by calculating the fluid aspirated and the wound leakages are considered for CFD simulation.
Results
It is observed from the stream line plot for the three different incisions that in the case of 1.8mm the aspiration is low and hence the fluid spillover from the anterior chamber is seen. Whereas in the case of 2.8mm higher aspiration is observed and also no-uniformity fluid flow with vacuum space observed within the anterior chamber. In the case of 2.2 mm fluid distribution is uniform and also optimum fluid level observed in the anterior chamber. Pressure indicated in the contour mapping for the 1.8 mm incision is above atmospheric pressure, where as it is lower for 2.2 mm.
Conclusion
Computational fluid dynamics analysis indicate that Microphaco techniques provide an increased safety margin for the Surgeon in terms of Fluidics aspect in the Anterior Chamber . It is concluded from the streamlines, pressure and temperature contours, 2.2 mm recommended incision size is optimum for phcoemulsification.