Methylprednisolone concentrations in the vitreous and the serum after pulse therapy

Purpose: Intravenous (IV) pulse of corticosteroids has been used to treat s evere eye inflammation from different origins. Whether such large doses res ult in vitreous levels that differ either in magnitude or duration from mor e conventional corticotherapy remain unsolved issues. The authors therefore determined levels of methylprednisolone hemisuccinate and methylprednisolo ne in the vitreous and serum of patients at different times after a single IV perfusion of methylprednisolone hemisuccinate. Methods: Fifty patients scheduled for a first vitrectomy received an IV inj ection of 500 mg hemisuccinate methylprednisolone at different times before surgery (from 15-24 hours). Patients were divided into two groups: those w ith (n = 21) and without (n = 29) retinal detachment (RD), Pure vitreous sa mples were analyzed by high-pressure liquid chromatography. Results: Both the ester and the nonester methylprednisolone forms were samp led in the vitreous, showing a slower rate of hydrolysis compared to the se rum. On average, the highest concentration of total methylprednisolone in t he vitreous was found at 2.5 hours and rapidly decreased for the group of p atients with RD. In the group of patients without RD, the highest concentra tion was reached at 6 hours and then slowly decreased. The antiinflammatory potency in the nondetached retina eyes was approximately 500 times more th an in the physiologic vitreous, but despite the route of administration (IV or oral), only 1/10 of the corticosteroid serum concentration was measured in the vitreous. Conclusion: High concentration of methylprednisolone is achieved by IV puls e therapy without changing the kinetic of entry in the vitreous of nondetac hed retina eyes when compared to conventional oral corticotherapy. Hydrolys is occurs in the vitreous resulting in high rate of active form. Pulse ther apy could be considered in cases of severe ocular inflammation involving th e posterior segment of the eye.