Abstract
Purpose:
To demonstrate the effect of low-intensity ultrasound on enhancing the transscleral delivery of serum protein into the eye in vivo.
Methods:
Fifteen New Zealand white rabbits received 0.1 ml of 0.1% fluorescein isothiocyanate conjugated bovine serum albumin (FITC-BSA) solution as a subtenon injection in both eyes. Ultrasound at 1 MHz with an intensity of 0.24 W/cm2 was applied over the injection site in the right eye for 5 minutes. The left eye served as a control. Both eyes were enucleated, and the whole vitreous was extracted from an eye. Fluorescence concentration in vitreous samples was measured. The penetration of FITC-BSA into the sclera was evaluated with the cryosectioned tissues using fluorescence microscope.
Results:
The mean concentration of vitreous fluorescence was 1.367 ± 0.309 μg/ml in the ultrasound-applied group and 1.101 ± 0.240 μg/ml in the control group, and the difference was statistically significant (P = 0.023, Mann-Whitney U test). It was also found that the scleral penetration of FITC-BSA was increased in the ultrasound-applied group compared to the control group.
Conclusions:
Low-intensity ultrasound could enhance the transscleral protein delivery into the eye, suggesting that this technique may be a useful non-invasive alternative for intraocular drug delivery.
Keywords: 503 drug toxicity/drug effects •
708 sclera •
599 microscopy: light/fluorescence/immunohistochemistry