The Crystallization of Silicone Oil Injected during Complicated Vitrectomy Surgery

ABSTRACT

PURPOSE: To report three cases of unexpected intraocular foreign bodies which were detected during silicone oil removal procedure following pars planar vitrectomy and silicone oil injection due to the severe vitreoretinal proliferations. METHODS: The medical records of three male patients, aged 61, 40, and 38 years, were reviewed retrospectively. We performed pars planar vitrectomy and silicone oil injection due to submacular hemorrhage with vitreous hemorrhage, tractional retinal detachment with proliferative diabetic retinopathy, and proliferative vitreoretinopathy, respectively. After the retinas were stabilized, we performed silicone oil removal at postoperative 1, 6, and 5 months, respectively. During the silicone oil removal procedure, intraocular foreign bodies were detected and removed with the vitreoretinal forceps. RESULTS: The intraocular foreign bodies were approximately 6 mm x 1 mm in size, transparent, rod-shaped, solid materials. Histopathologic findings didn't show any cellular or intraocular tissue components in and around the foreign bodies. Using electron spectroscopy for chemical analysis, the elemental compositions of the intraocular foreign bodies were determined to be the same as that of the silicone oil that had been previously injected in the eye. We therefore confirmed that those foreign bodies that were removed from the eyes were crystallized remnants of the silicone oil. CONCLUSIONS: Silicone oil can be crystallized after intraocular injection. Therefore, meticulous fundus examination including peripheral fundus is mandatory at the end of the silicone oil removal procedure to prevent any solid silicone foreign bodies from remaining in the eyes. Further investigations are needed to reveal the mechanisms of intraocular crystallization of the silicone oil.