RT Journal Article
A1 Takamura, Yoshihiro
A1 Tomomatsu, Takeshi
A1 Matsumura, Takehiro
A1 Takihara, Yuji
A1 Sakashita, Masanori
A1 Arimura, Shogo
A1 Gozawa, Makoto
A1 Yokota, Satoshi
A1 Inatani, Masaru
T1 Vitreous and aqueous concentrations of topically applied brimonidine tartrate 0.1%
JF Investigative Ophthalmology & Visual Science
JO Invest. Ophthalmol. Vis. Sci.
YR 2015
VO 56
IS 7 
SP 5747
OP 5747
SN 1552-5783
AB  To determine the vitreous and aqueous concentrations of brimonidine after topical application of the ophthalmic solution 0.1%. The prospective observational case series included patients with an idiopathic epiretinal membrane or macular hole who were scheduled for a pars plana vitrectomy. Brimonidine tartrate ophthalmic solution 0.1% was topically administered twice daily for 1 week preoperatively. Vitreous and aqueous humor were collected before vitrectomy, then, the brimonidine concentration was measured with liquid chromatography tandem spectrometry (LC/MS/MS). Twenty-four patients (19 phakic eyes and 5 pseudophakic eyes) were enrolled. The mean concentrations in the aqueous humor and vitreous were 336.0 ± 276.2 nM and 4.8 ± 3.2 nM, respectively. A significant relationship was observed between the vitreous and aqueous samples (P = 0.034, R2 = 0.22). Nineteen (79%) of the 24 eyes showed the more than 2 nM of brimonidine tartate concentration in the vitreous. In the phakic eyes, the mean concentration of brimonidine in the vitreous was 4.9 ± 3.3 nM while the mean concentration in the pseudophakic eyes was 4.1 ± 2.4 nM, demonstrating no significant difference between pseudophakic and phakic eyes (P = 0.59). After one week of dosing, most of the patients who topically received brimonidine tartrate 0.1%, the concentration in the vitreous of the molecule above 2 nM, which is known to activate neuroprotective a-2 receptors in animal retina. The drug penetration into the vitreous seems to be independent of lens status. 
RD 4/11/2021