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Pharmacokinetics of anti‐ VEGF and steroid agents in vitrectomized eyes with diabetic macular edema
Author(s) -
Papastefanou V.
Publication year - 2015
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2015.0127
Subject(s) - vitrectomy , medicine , pharmacokinetics , ophthalmology , dexamethasone , macular edema , triamcinolone acetonide , ranibizumab , bevacizumab , pharmacology , surgery , visual acuity , chemotherapy
Summary Anti‐ VEGF and steroid agents for diabetic macular edema ( DME ) in a vitrectomized eye is fraught with difficulties, bearing in mind the numerous confounding factors in DME . The pharmacokinetic parameters are affected as the vitreous cavity milieu is altered and the vitreous consistency is not reformed post vitrectomy ( PPV ). Pharmacokinetic data are largely based on experimental animal models. VEGF clearance is increased in the vitrectomized eye compared to the non‐vitrectomized eye, but there is little direct evidence that the protein expression profile in the vitreous cavity is altered after vitrectomy. Whilst some studies have demonstrated longer intravitreal retention for Bevacizumab compared to Ranibizumab and reduced half‐life for both agents after PPV , other studies have found no changes. There is a characteristic lack of pharmacokinetic data for anti‐ VEGF agents in human vitrectomized eyes. The vitreous half‐life of triamcinolone acetonide ( TA ) after intravitreal injection was reduced in vitrectomized eyes in both animal models and human eyes. No pharmacokinetic differences between vitrectomized and non‐vitrectomized eyes are noted in animal eyes following the injection of the Dexamethasone implant (Ozurdex, Allergan).