Abstract
Purpose :
To measure the dose of triamcinolone acetonide (TA) delivered by variations on a previously described technique of office based centrifuge concentration for both Triesence and Kenalog-40.
Methods :
Entire vials of Triesence and Kenalog-40 were drawn into 1mL syringes. The plunger extending out of the syringe was cut off and the syringe was centrifuged for either 1 or 2 minutes. A second plunger was then placed into the syringe to expel the supernatant so that a volume of 0.03mL, 0.05mL or 0.1mL of concentrated TA remained. The concentrated TA suspensions were injected onto individual pieces of filter paper. Filter papers were allowed to dry in a fume hood for 24 hours. The dry TA crystals on filter paper were weighed and the filter paper weight subtracted to determine the mass of dry TA, representing the dose of TA injected.
Results :
Forty-five measurements were made (15 Triesence, 30 Kenalog-40, n=5). The doses of TA increased with increasing injection volume. The average measured Triesence doses were 9.18mg, 13.68mg and 21.88mg respectively for the 0.03mL, 0.05mL and 0.1mL injected volumes (p<0.001). Kenalog-40 doses were 6.06mg, 6.76mg and 7.89mg in the 1 minute centrifugation group, and 6.10mg, 7.08mg and 8.00mg in the 2 minute centrifugation group for the 0.03mL, 0.05mL and 0.1mL injected volumes, respectively (p=0.337 and 0.194). There was no statistically significant difference between the 1 and 2-minute groups (p>0.7). Triesence had a larger dose delivered compared to an equal volume of Kenalog-40 for each of the 3 volumes (p<0.05).
Conclusions :
Centrifuge concentration of Triesence yielded a larger dose of TA delivered compared to equal injected volumes of Kenalog-40. The total dose of TA delivered increased with increasing injection volume for Triesence and Kenalog-40, however, this difference was only statistically significant in the Triesence groups. These findings may be related to the smaller particle size as well as larger amount of TA in each vial of Triesence versus Kenalog-40. Increasing the duration from 1 minute to 2 minutes did not significantly increase the dose of Kenalog-40. Based on comparison to previous studies, office based centrifuge concentration of TA produces a more consistent, higher TA amount delivered per volume of injection than conventional methods, which yields benefits with respect to duration of effect and cost.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.