Abstract
Purpose:
To determine the anatomic characteristics and pharmacokinetic properties of intravitreally-placed I-124-aflibercept after pars plana lensectomy and to compare these with non-operated control eyes in a rabbit model.
Methods:
Three Dutch-belted rabbits underwent pars plana lensectomy and four served as non-surgical controls. Twelve days after surgery each rabbit underwent intravitreal injection in one eye with I-124-aflibercept. Serial imaging with PET-CT were obtained on days 0, 2, 5, 7, 14, 21, 28 and 35. Radioactivity emission was measured in becquerels/ml (Bq/ml) and was used to calculate half-lives for each agent.
Results:
The intravitreally placed radiolabeled agents were contained within the vitreous cavity for the duration of the study. The average clearance half-lives with standard error and 95% confidence intervals for I-124-aflibercept after correction for radioactive decay was 4.58 +/- 0.07 (4.28, 4.87) days in unoperated eyes and 1.95 +/- 0.02 (1.88, 2.02) (p<0.0001) days after lensectomy.
Conclusions:
Intravitreal clearance of aflibercept was significantly increased following lensectomy as compared to non-surgical controls. Consideration for more frequent intravitreal anti-VEGF dosing regimens may be made for patients who are aphakic.
Keywords: 550 imaging/image analysis: clinical •
503 drug toxicity/drug effects