Histopathologic abnormalities in rabbit retina after intravitreous injection of expansive gases and air

Purpose: To evaluate histopathologic retinal changes in rabbit eyes after i njection of pure perfluoropropane (C3F8) gas, pure sulfur hexafluoride (SF6 ) gas, or air into the vitreous cavity. Methods: Air, C3F8 gas, or SF6 gas (0.4 mL each) were injected into rabbit vitreous cavities, Two, 4, and 6 weeks later, light and electron microscopi c examinations were conducted, and the immunohistochemical localization of glutamate in the retina was studied. Noninjected eyes served as controls. Results: At all time points, thinning or disappearance of the outer plexifo rm layer in the superior retina in eyes that received C3F8 gas was found; t he inferior retina was the same as in controls. In eyes that received SF6 g as or air, light and electron microscopy showed that the superior and infer ior retina were the same as in controls at all time points. Immunohistochem ical examination showed abnormal glutamate distribution of the superior ret ina in eyes injected with C3F8 gas, SF6 gas, or air. However, glutamate dis tribution was the same as in controls in the inferior retina in eyes inject ed with C3F8 gas, SF6 gas, or air. Conclusions: Retinal tamponade using intraocular gases induces histopatholo gic retinal changes in the superior retina of the rabbit eye, where the gas es are in continuous contact with the eye.