Evaluation of extended release brimonidine intravitreal device in normotensive rabbit eyes


Sunil P Deokule, MD
Department of Ophthalmology and
Visual Sciences
University of Kentucky
E-328, Kentucky Clinic
S Limestone
KY 40536
Tel: (859) 218 2629
Fax: (859) 323 1122
Email: spdeokule@gmail.com


Purpose:  To evaluate the safety profile of a brimonidine extended release intravitreal implant, in normotensive rabbit eyes.

Methods:  Devices were made from hollow poly-l-lactic acid (PLA) tubes and contained hundred micrograms of brimonidine pamoate. Device was injected intravitreally in one eye of 12 New Zealand pigmented rabbits, whereas other eye was injected with a sham implant in masked fashion. Ocular examination was conducted at baseline and months 1, 3 and 6 including dilated fundus examination and electro-retinogram (ERG). Four rabbits were sacrificed at each time-point for retinal histology. ERG data were compared between groups and time-points using anova.

Results:  No complications were reported from either eye of any rabbits over a 6-month period. Photopic A wave was reduced in the control eye at 1 month compared with baseline (p < 0.01). There was no significant difference in other ERG parameters between the groups at different time-points. Gross retinal histology was normal at all time-points.

Conclusion:  Extended release intravitreal brimonidine device was found to be safe and in normotensive rabbit eyes.