Changes of amounts of intraorbital pressure and exophthalmos caused by intravenous infusion of mannitolum

Objectives To evaluate the effects of intravenous in fusion of mannitolum on the degree of intraorbital pressure and exophthalmos and investigate the clinical value of measurement of intraorbital pressure and exophthalmos in the diagnosis and treatment of dehydration.Methods The intraorbital pressure and exophthalmos of the normal eyes of 86 patients whose one eye had cataract and needed surgical treatment were measured before and after intravenous infusion of mannitolum.Results The degree of intraorbital pressure and exophthalmos after infusion of mannitolum was remarkably lower than that before infusion. It reached the lowest in two hours. The intraorbital pressure was decreased by 0. 67 kPa (P0.01) and the exophthalmos was decreased by 2.1mm (P0. 01 ).Conclusion Hyperosmotic agents may cause the water loss of the orbital tissue and decrease the intraorbital pressure and exophthalmos. These changes of intraorbital pressure and exophthalmos may be measured by the immediate contact orbitonometer. The measurement of intraorbital pressure and exophthalmos may provide evidence to the diagnosis and treatment of dehydration.