Mechanisms of Retinal Displacement After PFCL-Assisted Rhegmatogenous Retinal Detachment Repair: Insights From a Computational Model.

Purpose: To investigate the mechanical forces exerted by perfluorocarbon liquid (PFCL) during pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD) using a computational model of retinal dynamics. Methods: A continuous load was applied to the retina by simulating PFCL infusion into the vitreous cavity at a constant fill rate for varying PFCL densities. Using this loading condition, the model computed the corresponding movement of subretinal fluid (SRF) and the resulting retinal displacement throughout the reattachment process. Results: In our model, the PFCL pushes the SRF against gravity, which displaces the fluid anteriorly away from the PFCL bubble. This flow of SRF induces shear stress, contributing to retinal stretching. In addition to the flow-induced stretching, the direct mechanical load from the PFCL will also directly result in retinal stretching. As a result, the retina undergoes a displacement or stretch of approximately 200 to 240 µm, and the residual stretch after the removal of PFCL is approximately 100 µm. The model, representative of a PPV setting, further demonstrates that PFCL with higher density can exert greater load on the retina, leading to increased residual displacement following retinal reattachment. Conclusions: These simulations established a framework for investigating retinal displacement resulting from RRD repair using PPV with PFCL. The results suggest that a lower-density PFCL can help minimize retinal displacement by reducing mechanical loading on the retina. This model can be further extended to examine the influence of additional clinical variables, such as the location and size of retinal breaks, to support optimized surgical planning and improved visual outcomes.