Purpose
Condensation on the posterior surface of Intraocular lens (IOL) during pars plana vitrectomy (PPV) is a known phenomena that can deteriorate the intra-operative view to the fundus. The purpose of this study was to determine whether perfluorocarbon liquids (PFL) used during PPV can exacerbate condensation on an IOL.
Methods
Three types of acryilc and silicone IOLs were used in this study. A pair of IOLs were placed in 2 different containers, both with atmospheric relative humidity kept constant at 48%. A Peltier element was used to control the temperature of the substrate below IOLs. Prior to the test, the IOLs were plasma cleaned from any organic impurities to have identical surface energy on each IOL. One IOL was then covered with a thin film of PFL, while other was kept clean for control. Experiments were performed at two substrate temperatures of 10 and 20 degrees Celcius.
Results
We observed substantial condensation on the IOLs covered with PFL while the one without PFL did not show any condensation. This was particularly obvious for SN60WF lens. These experiments demonstrate that when water condenses on the bare surface of an IOL, it forms a continuous thin film. However, with a PFL film on the surface, due to interfacial tension between water and PFL, small droplets of water are formed on the surface.
Conclusions
Due to the lower surface tension of PFL compared to water, PFL is the preferred fluid that wets on the IOL surface when it evaporates inside eye. In this case, water condenses on top of PFL layer and forms a fog layer. Further studies are needed to determine if these experimental conditions translate into an explanation for intraoperative IOL condensation associated with PFL usage.
Keywords: 762 vitreoretinal surgery •
567 intraocular lens