Abstract
Purpose: :
Adherent silicone oil on intraocular lenses following retinal detachment surgery induces large and irregular refractive errors, multiple images and gives rise to glare, distorted and often poor vision. Perfluorohexyloctane (F6H8) proved to be disappointing as a solvent and the removal of adherent oil remains challenging often requiring mechanical wiping or intraocular lens (IOL) explantation. F4H5 is a new semifluorinated alkane into which silicone oil is much more soluble (up to 100% of its weight). We carried out experiments to establish the effectiveness of F4H5 in removing silicone oil in vitro.
Methods: :
We used two groups of 3 IOL from two manufacturers: ALCON MA60 (+22.5dpt) and OCULARVISION PMMA (+22.5dpt). IOLs were firstly immersed in phosphate buffered saline, secondly in silicone oil (1000cS), then in F4H5 for 10-min and lastly vigorously agitated in F4H5 for 1 minute. The IOLs were weighed at each stage using scales accurate to 0.0001g to measure the weight of oil adherent to them. We used dynamic contact angle analysis (Cahn, DCA 322) to measure the surface properties of the IOLs.
Results: :
Immersion in F4H5 alone removed 96.1%(±1.23), by weight, of the adherent silicone oil from the ALCON lenses and 95.6%(±1.44) from the OCULARVISION lenses. Immersion combined with 1 minute of agitation in F4H5 increased the removal to 98.8%(±0.46) from the ALCON lenses and to 100% (within ±0.0001g) from all OCULARVISION lenses. All IOL were optically clear after oil removal. After contact with silicone oil dynamic contact angle hysteresis graphs of both groups of IOL were altered compared to baseline curves. Even after removal of the adherent oil with F4H5, the contact angle curves of the lenses did not return to baseline suggesting a permanent alteration of the surface properties of the IOLs. All these measurements were highly reproducible.
Conclusions: :
We have demonstrated that F4H5 is effective at removing the bulk of the silicone oil from both types of IOL. Clinically, this is highly significant and may remove the need for mechanical wiping of the lenses or lens exchange.
Keywords: retinal detachment • clinical laboratory testing • refractive error development