Abstract
Purpose:
The purpose of this study was to compare the total amount of triamcinolone acetonide (TA) delivered into a pig eye when injected into the suprachoroidal space using a Clearside Biomedical proprietary microneedle or into the vitreous using a standard 30 gauge needle.
Methods:
Whole pig cadaver eyes (Sioux-Preme Packing) enucleated within 24 hours after death were used for all injections. Intravitreal and suprachoroidal injections of TA were performed using Triesence® (Alcon Labs). Intravitreal injections were performed using a 30 g needle (Becton-Dickinson) and suprachoroidal injections were performed using a Clearside Biomedical proprietary microneedle. 1 mL syringes (Becton-Dickinson) were loaded with the required amount of Triesence® at each of the three volumes assessed: 50, 100, and 150 µL (2, 4, and 6 mg, respectively). The residual amount of TA present in the syringe/needle assembly after injection was determined by RP-HPLC. The total amount of TA delivered to the eye for each dose volume was determined as the difference in the total amount loaded into a syringe before injection into the pig eye versus the residual amount of TA recovered from the syringe/needle assembly after injection.
Results:
Average total dose administered following 50, 100 and 150 µL TA injected into the suprachoroidal space ranged from 86-92% of the target dose level, while average total dose administered following 50 and 100 µL TA injected into the vitreous ranged from 88-89%. Virtually no difference was observed between the two routes of administration and needles for each volume.
Conclusions:
The target dose level of TA can be consistently delivered into the SCS using a microneedle or into the vitreous using a 30 g needle. Total amount of TA delivered was similar between the two administration routes.
Keywords: 561 injection •
452 choroid •
763 vitreous