Objective: This study investigated the effect of brimonidine on the anterior-chamber angle in eyes with narrow angles using noncontact three-dimensional anterior-segment analyzer Pentacam. Methods: Nine eyes with narrow angles were distributed to one of three treatment groups—single topical dose of 0.15% brimonidine tartrate, 0.5% timolol maleate (positive control), or balanced salt solution (negative control)—in a prospective, single-masked, crossover, comparative trial. The primary outcome measure was anterior-chamber angle at baseline, and 2 and 4 hours after instillation of the treatment drug. Secondary outcome measures were pupil diameter, intraocular pressure (IOP), and anterior-chamber depth and volume. After a two-week washout period, eyes were crossed over to the other treatment modes. All baseline and posttreatment measurements were taken. Repeated analysis of variance (ANOVA) was used for statistical analysis. Results: Anterior-chamber angle, depth, and volume did not differ significantly for all treatment groups. Brimonidine caused a significant decrease in pupil diameter, most notably 2 hours after instillation, from baseline of 2.36 ± 0.37 mm to 2.17 ± 0.35 mm. (p = 0.03). There was a significant decrease in IOP from baseline to hour 4 after treatment for both brimonidine (11.4 ± 2.2 to 9 ± 1.8 mm Hg, p < 0.001) and timolol (11.9 ± 2.3 to 9.4 ± 2.1 mm Hg, p = 0.003). Conclusions Brimonidine produced a miotic trend with no significant opening of the anterior-chamber angle in patients with narrow angles.
Brimonidine Tartrate ; Miosis ; Intraocular Pressure

PURPOSE: To investigate the effects of bimatoprost on the permeability of cultured human trabecular meshwork cells (HTMC) monolayer. METHODS: HTMCs were cultured until confluency in the inner Transwell chamber and then exposed to benzalkonium chloride, brimonidine, latanoprost or bimatoprost for 1 week. Carboxyfluorescein permeability through the HTMC monolayer was measured using a spectrofluorometer after 2 hours in the outer chamber. Cellular viability was assessed using the MTT assay. RESULTS: Each drug diluted at 1/1000X did not affect the cellular survival (p > 0.05). Brimonidine, latanoprost and bimatoprost did not affect the carboxyfluorescein permeability through the HTMC monolayer (p > 0.05). The carboxyfluorescein permeability was not different between latanoptost and bimatoprost after 1 week of exposure (p > 0.05). CONCLUSIONS: Bimatoprost, a drug known to increase trabecular outflow, does not affect the carboxyfluorescein permeability through the HTMC monolayer. Thus, the effect on the trabecular outflow of bimatoprost may not be significant.
Benzalkonium Compounds ; Humans ; Permeability* ; Trabecular Meshwork* ; Bimatoprost ; Brimonidine Tartrate

PURPOSE: To analyze the effect of the daily use of brimonidine tartrate 0.15% on the dark-adapted pupil diameter in dark brown irides. METHODS: Twenty-five healthy volunteers administered brimonidine tartrate 0.15% to their right eyes once daily for 3 weeks. Infrared digital photographs of the pupil were taken before administration and 1 hour and 4 hours after administration after dark adaptation (at <0.1 lux ambient illumination for 5 minutes). The diameters of both pupils were measured on the first day, on administration days 7 and 21, and on washout day 7. RESULTS: Four hours after the first administration, pupils showed a decrease of 0.95+/-0.74 mm, 1.03+/-0.94 mm, 0.61+/-0.85 mm on the first day, administration day 7, and administration day 21, respectively (p<0.01), compared with baseline data. The anti-mydriatic effect of brimonidine was sustained for 3 weeks, but the proportions of the eyes showing a reduction in pupil diameter by 0.5 mm or more were 84%, 76%, 68%, and 52% at 4 hours on the first day, administration days 7 and 21, and washout day 7, respectively. CONCLUSIONS: The anti-mydriatic effect of the daily use of brimonidine 0.15% on dark brown irides in a scotopic condition is maintained during the instillation period but has a tendency to fade over time. This point should be considered when using this compound as a miotic agent.
Dark Adaptation ; Eye ; Lighting ; Pupil ; Quinoxalines ; Brimonidine Tartrate

PURPOSE: To compare the effectiveness of 0.2% brimonidine tartrate and that of 0.5% apraclonidine hydrochloride for controlling IOP elevation after Nd:YAG laser capsulotomy. METHODS: Thirty eyes were given with 0.2% brimonidine (group 1) and fourteen eyes with 0.5% apraclonidine (group 2) before and after the procedure. Fifteen eyes served as untreated controls (group 3). Intraocular pressure and visual acuity were measured preoperatively and 1 hour, 3 hours, 24 hours, and 1 week postoperatively in all cases. RESULTS: The postoperative mean intraocular pressures of group 3 (14.97+/-3.58, 16.47+/-3.93 mmHg) at 1 hour and 3 hours were statistically significant higher than those of group 1 (11.23+/-3.43, 11.50+/-3.01mmHg), and those of group 2 (10.79+/-3.51, 11.57+/-3.03 mmHg)(p< 0.05), but, there were no statistically significant differences in mean IOP at 1 hour and 3 hours between group 1 and group 2 (P=0.569, P=0.610). At 1 hour and 3 hours, there was no case of IOP elevation of 5 mmHg above baseline in group1 and group 2. but, there were 5 cases (33.3%) at 1 hour and 6 cases (40%) at 3 hours in group 3. CONCLUSIONS: This result suggests that 0.2% brimonidine and 0.5% apraclonidine are equally effective for preventing acute IOP elevation after Nd:YAG laser capsulotomy, that is, 0.2% brimonidine is an effective and well-tolerated agent for preventing acute IOP rises after Nd:YAG laser posterior capsulotomy.
Intraocular Pressure* ; Posterior Capsulotomy* ; Visual Acuity ; Brimonidine Tartrate

Effect and side effects of adding 0.2% brimonidine to beta blockers was studied in 44 eyes of 32 glaucoma patients with inadequately controlled intraocular pressure[IOP]with beta blockers alone. Routine eye examination and IOP measurement were performed before the additive therapy. 0.2% brimonidine eye drops were topically applied three times a day with previously used beta blockers. IOP was measured at 1 week, 1 month, and 3months after the combined therapy. Mean IOP was 17.2 +/-1.8 millimeters of mercury before combined therapy ;13.5 +/-1.6 millimeters of mercury after 1 week, 14.3 +/-2.5 millimeters of mercury after 1 month and 13.6 +/-2.3 millimeters of mercury after 3 months of therapy. Side effects of combined therapy were oral dryness[25.0%], ocular pain[9.4%], and blurring[6.3%]. These results indicate that adding 0.2%brimonidine in patients treated with beta blockers causes a further reduction of IOP that may prove to be clinically useful in glaucoma therapy.
Glaucoma ; Glaucoma, Open-Angle* ; Humans ; Ophthalmic Solutions ; Brimonidine Tartrate

PURPOSE: To investigate the effects of 0.15% brimonidine tartrate ophthalmic solution spray on the luminal changes in the nasolacrimal excretory system. METHODS: A prospective study was performed on 52 eyes in 26 patients complaining of epiphora in both eyes. The randomly-assigned 26 test eyes (cases) received spray of the solution through the nasal cavity, and the other 26 eyes (controls) were irrigated with the same drug through the inferior calnaliculus. Dacryocystography was then performed to observe the luminal changes jn the nasolacrimal excretory system, patient symptoms and physiologic drainage functions. RESULTS: The changes in lumen width of the nasolacrimal duct (NLD) were noted, and the changes in lumen width of the lacrimal sac were not significant in either mode. The upper and middle parts of the NLD were widened more in the irrigation group, and the lower part of the NLD was widened more in the spray group. Though there was no significant difference in the physiologic drainage functions, the patients in both groups reported reduced symptoms. CONCLUSIONS: Brimonidine tartrate spray altered the width of the NLD and improved the subjective symptoms of patients. Therefore, the spray can be applied in functional NLD obstruction patients before the surgical procedure.
Drainage ; Eye ; Humans ; Lacrimal Apparatus Diseases ; Nasal Cavity ; Nasolacrimal Duct ; Phenobarbital ; Prospective Studies ; Quinoxalines ; Brimonidine Tartrate

PURPOSE: The purpose of this study was to evaluate and compare the prophylactic effect of brimonidine 0.2% and apraclonidine 0.5% in preventing intraocular pressure(IOP) elevation in patients undergoing laser iridotomy. METHODS: The 24-hour, placebo-controlled, randomized, clinical trial was conducted to determine the efficacy of brimonidine 0.2% and apraclonidine 0.5% in controlling IOP after combined argon and Nd:YAG laser peripheral iridotomy. The 110 eyes(56 eyes with angle closure glaucoma, 54 eyes with narrow occludable angle) were randomized to receive brimonidine 0.2%, apraclonidine 0.5% or artificial tear(as placebo) 20 minutes before the procedure. IOP was measured before and 1, 2, and 24 hours after the procedure by masked observer using Goldmann applanation tonometry. The difference between preoperative(baseline) IOP and the highest postoperative IOP was recorded as the maximum IOP rise. RESULTS: The mean of maximum IOP rise was 1.1+/-5.6 mmHg in the brimonidine group, 1.0+/-2.9 mmHg in the apraclonidine group and 4.7+/-7.6 mmHg in the placebo group. There was statistically significant decrease in IOP in both drug groups compared to the placebo group(p<0.05). The incidence of maximum IOP rise greater than 5 mmHg was 18.2%(6/33 eyes) in the brimonidine group, 11.4%(4/35 eyes) in the apraclonidine group and 42.9%(18/42 eyes) in the placebo group. But no statistical difference was found between the brimonidine group and apraclonidine group(p>0.05). CONCLUSIONS: Both brimonidine 0.2% and apraclonidine 0.5% were significantly effective in preventing IOP spike following laser iridotomy procedure. There was a tendency toward less efficacy with brimonidine 0.2% compared to apraclonidine 0.5%, but this was statistically insignificant.
Argon ; Glaucoma, Angle-Closure ; Humans ; Incidence ; Intraocular Pressure* ; Manometry ; Masks ; Brimonidine Tartrate

BACKGROUND: Mechanical allodynia is generally resulted from nerve damage by direct injury or inflammation. Thus, this study was designed to compare the antiallodynic effect of morphine, brimonidine and rilmenidine in two models of neuropathic pain, that is, induced by nerve ligation and neuritis. METHODS: Rats were prepared with tight ligation of the L5/L6 spinal nerves (SNL group) or with Freund's complete adjuvant (FCA) administration evoked sciatic inflammatory neuritis (SIN group). Antiallodynic effects by intrathecal morphine, brimonidine and rilmenidine were measured by applying von Frey filaments to the lesioned hind paw. Thresholds for withdrawal response were assessed and converted to % MPE to obtain an effective dose 50% (ED 50) and a dose response curve. RESULTS: Either SNL group or SIN group showed marked mechanical allodynia in the lesioned hind paw. Antiallodynic effects of morphine were different between two groups. That is ED 50 was 0.16 microgram (SIN) and 8.12 microgram (SNL), and dose response curve of the SIN group shifted left from that of the SNL group. The difference between SIN and SNL groups was statistically significant (P < 0.05). With the brimonidine or rilmenidine administration, ED 50 s were 0.12 microgram (SNL) and 0.37 microgram (SIN) and 2.16 microgram (SIN) and 11.46 microgram (SNL), respectively. And the shift to left of dose response curve from the SNL group is more prominent with rilmenidine administration. CONCLUSIONS: These results suggest morphine and rilmenidine showed a better effect on reducing the mechanical allodynia induced by FCA administration.
Animals ; Hyperalgesia ; Inflammation ; Ligation ; Morphine ; Neuralgia ; Neuritis ; Oxazoles ; Quinoxalines ; Rats ; Spinal Nerves ; Brimonidine Tartrate

BACKGROUND: Clonidine, an alpha2 adrenoceptor agonist, has been known to have antinociceptive and antiallodynic effects. The antinociceptive and antiallodynic effects of brimonidine, a new selective alpha2 agonist, have not been evaluated yet in rats. Behavioral tests were performed to investigate the effects of systemically and spinally administered brimonidine on nociception and mechanical allodynia and the effect of spinal nerve ligation (SNL) on antinociception. METHODS: Rats were prepared with tight ligation of spinal nerves and/or a lumbar intrathecal catheter implantation. Using a hot plate (HP) test or von Frey hair (VFH) test, the effect of intraperitoneal (I.P.) and intrathecal (I.T.) brimonidine in normal and SNL rats were examined. I.P. brimonidine (100 - 1,000 microgram) and I.T. brimonidine (0.1 - 3.0 microgram) were given to examine the antinociceptive effect on an HP test. After a SNL, a HP test was conducted at the same doses of brimonidine to compare with the preoperative state. I.T. brimonidine (0.03 - 3.0 microgram) and saline (control) were administered to examine the antiallodynic effect in SNL rats. In addition, an antagonistic study with yohimbine 1.0 mg/kg I.P. was performed to investigate the reversal of the antiallodynic effect of brimonidine. Allodynic thresholds for lesioned hindpaw withdrawl to a VFH test were assessed and converted to %MPE. RESULTS: I.P. brimonidine produced an antinociceptive effect, and I.T. brimonidine also produced a significant antinociceptive effect (P < 0.05). After an SNL, I.T. brimonidine produced a dose-dependent antinocicpetive effect. In addition, I.T. brimonidine produced a dose-dependent antiallodynic effect which is antagonized by yohimbine (P < 0.05). CONCLUSIONS: The results suggest that brimonidine has a more potent antiallodynic effect when given intrathecally.
Adrenergic Agonists* ; Animals ; Catheters ; Clonidine ; Hair ; Hyperalgesia ; Ligation ; Nociception ; Rats ; Spinal Nerves ; Yohimbine ; Brimonidine Tartrate

Brimonidine(Alphagan)is a relatively selective-adrenoceptor agonist that activates receptor in the ciliary body, which lowers intraoculat pressure by decreasing aqueous production and increasing uveoscleral outflow. We investigated the short-term intraocular pressure lowering effect and side effect of 0.2% brimonidine in 8 eyes in 8 normal volunteers. Brimonidine was administered every 8 hours for 7 days. The intraocular pressure, pupil size, pulsatile ocular blood flow of both eyes, blood pressure, and pulse rate were obtained 2, 4 and 8 hours, and 1 and 7 days after instillation. The mean intraocular pressure was lowered in both eyes. The blood pressure, pulse rate, and pupil size were not changed before and after the instillation. The pulsatile ocular blood flow was not changed either, The only side effect which patients complanined of was nasal stuffiness in two of the patients. We concluded that 0.2% brimonidine is a good ocular hypotensive drug that has an intraocular pressure lowering effect in normal Koreans and also has few side effects.
Blood Pressure ; Ciliary Body ; Healthy Volunteers ; Heart Rate ; Humans ; Intraocular Pressure ; Pupil ; Brimonidine Tartrate