Related Experiment Video
Updated: Jun 18, 2025

Use of Rabbit Eyes in Pharmacokinetic Studies of Intraocular Drugs
Published on: July 23, 2016
Calculated Drug Concentrations in Currently Available Intravitreal Therapies: Determination of Dilution Factor and
Andreas F Borkenstein1, Eva-Maria Borkenstein1, Armin Presser2
1Ophthalmology, Borkenstein and Borkenstein, Private Practice at Privatklinik Kreuzschwestern Graz, Graz, AUT.
Abstract:
In ophthalmology, intravitreal therapies are currently not personalized/customized and are not adjusted to the individual vitreous volume. With reference to the recently published calculation formula for a more accurate estimation of the vitreous body, we determined the dose of intravitreal medication for different vitreous volumes and compared them with the average volume. Using the axial length of the eye, the formula for the vitreous volume exact (VIVEX) can provide a more accurate indication of the vitreous volume in individual cases than an assumed standard volume of 4 mL. The concentration of active substances in small eyes may be twice as high as that in normal-sized emmetropic eyes. In contrast, large eyes may show less than half of the recommended drug concentration. The calculated concentrations of the investigated intravitreal drugs in small and large eyeballs showed impressive differences with large deviations from the recommended doses. Further systematic studies should follow to find out whether this has any impact on the effectiveness or side effects of the injected drugs.
More Related Videos
Related Concept Videos
Renal Failure: Dose Adjustments
Reduced renal clearance and elimination rate are common outcomes of renal impairment. These alterations lead to a prolonged elimination half-life and an altered apparent volume of distribution for drugs. As a result, dosage adjustments are typically necessary to maintain optimal drug levels in the body.
However, dosage adjustments...
Rational Dosage Regimen: Maintenance Dose and Loading Dose
In most cases, drugs are administered repetitively or infused continuously to maintain a steady-state concentration in the body. At a steady...
Dosage Regimen: Fixed Dose
Fixed-dose regimens can be used for various routes of administration, including intravenous (IV) injections and oral medications. For IV administration, a predetermined amount of the drug is...
Drug Dosage Regimen: Overview
Typically, the starting dose and dosing interval are guided by the manufacturer's recommendations based on clinical trials conducted during and after drug...
Drug Distribution: Volume of Distribution
Volume of Distribution

