Retinal Toxicity of Intravitreal Polyethylene Glycol 400
Shriji Patel1, Joshua M Barnett1, Stephen J Kim1
1Vanderbilt Eye Institute, Vanderbilt University Medical Center , Nashville, Tennessee.
Purpose:
Polyethylene glycol (PEG)-400 is a clear, colorless viscous liquid that readily dissolves many hydrophobic drugs. It is a widely used commercial solvent and vehicle for many pharmaceutical and cosmetic products. The purpose of this study is to investigate the intravitreal safety of PEG-400 to determine its suitability as a potential vehicle for intraocular drug delivery.
Methods:
Six healthy, male, Dutch Belted rabbits, weighing between 2.0 and 3.0 kg, were used for this experiment. The left eye of each animal received a single 0.1 mL intravitreal injection of PEG-400. Complete eye exams and dark- and light-adapted electroretinograms (ERG) were obtained at baseline and at 1 and 4 weeks after injection. After the 4-week ERG was completed, animals were euthanized, eyes were enucleated, and histology and transmission electron microscopy (TEM) were performed.
Results:
Ophthalmic examinations demonstrated diffuse signs of retinal degeneration and cataract formation in all 6 eyes injected with PEG-400, which was apparent at 1 week, but more evident by 4 weeks. Photopic and scotopic ERG studies demonstrated significant reduction in amplitudes at 1 and 4 weeks after injection compared to baseline. Histopathological and TEM analysis of eyes demonstrated both inner and outer retinal atrophy.
Conclusion:
Intravitreal injection of PEG-400 resulted in severe ocular toxicity.
