[Pharmacokinetics of Intravitreally Administered VEGF Inhibitors]

Background: In addition to topical, periocular and systemic administration, intravitreal injection has been established in recent years as an additional standard procedure for ophthalmological drug delivery. This route of administration is now most frequently used for the therapy of retinal diseases with vascular endothelial growth factor (VEGF) inhibitors.

Material And Methods: A selective literature review and an analysis of own research data were carried out.

Results: Intravitreal administration achieves high drug concentrations in the target tissue while minimizing systemic drug exposure. Depending on properties such as molecular weight and binding capacity to the neonatal Fc receptor, intravitreally applied VEGF inhibitors can exhibit relevant differences in intraocular and systemic pharmacokinetics. Moreover, the pharmacokinetics can be affected by properties of the individual eye, such as ocular volume, vitreous liquefaction, and prior vitrectomy.

Conclusions: Pharmacokinetics of intravitreally administered drugs determine both the duration of ocular effect and the degree of systemic exposure and are thus of clinical relevance with regard to the reinjection strategy and systemic safety.