4. Brimonidine 0.1% - Safety Profile
Better safety profile than Brimonidine 0.2% and 0.15%
- 41% lesser incidence of allergic conjunctivitis than 0.2% of
Brimonidine
- Overall lesser incidences of treatment related adverse events
- New formulation of 0.1% have improved safety profile over 0.15%
Brimonidine
- Rate of discontinuation is significantly lesser compared to
Brimonidine 0.2%
5. GLAUCOMA: OPTIC NERVE DAMAGE
Elevated IOP
Mechanical back pressure
On the junction of optic nerve/retina
Reduce the blood supply to the optic nerve
Loss of blood supply (< in pOBF)
Ischaemia
RGC cell loss
6. GLAUCOMA: OPTIC NEUROPATHY
Axons of optic nerve die
Visible optic nerve head, assumes
a cupped appearance
Peripheral vision declines as axons
are lost
Central vision affected due to
severe axonal loss
Finally, leads to blindness
7. OPTIC NEUROPATHY
What is optic neuropathy?
Optic neuropathy means death of the neurons of
the retina.
8. CRITERIA FOR EVALUATION OF NEUROPROTECTIVE
COMPOUNDS
1. Compound should have a specific target in the
retina
2. Should have a profile of neuroprotective activity
3. Drug should reach to target issue in
pharmacological concentrations sufficient to
activate its target.
10. BRIMONIDINE :
THE NEUROPROTECTIVE a2 AGONIST
IOP lowering is the main aim of any anti-glaucoma
agent.
But, there is something beyond this IOP
reduction…. Neuroprotection.
11. BRIMONIDINE: THE NEUROPROTECTIVE AGENT
Brimonidine brought about a higher rate of RGC survival
0
0.5
1
1.5
2
2.5
3
Vehicle 14 0
Time of injection of brimonidine before nerve injury (hrs)
RGC
survival
(Ratio)
Survey of Ophthalmol.,May 2001,45, Suppl.3,S290-S294.
12. BRIMONIDINE: THE NEUROPROTECTIVE AGENT
Brimonidine and not timolol showed significant
neuroprotective effects.
0
5
10
15
20
25
30
35
Brimonidine Timolol Vehicle
Drug
Percent
RGC
lost
Survey of Ophthalmol.,May 2001,45, Suppl.3,S290-S294.
13. pulsatile Ocular Blood Flow
It is the blood supply to the retina and optic nerve head
thereby providing oxygen and nutrients.
• Alpha 2 adrenoceptors mediate vasoconstriction.
• Brimonidine brings about vasodilation of the
endothelial cells of the blood vessel.
• Therefore, flow of blood to the retinal layers increases.
14. BRIMONIDINE : Effect on pOBF
One drop of brimonidine increased the pOBF value from 15.7%
to 26.1% with a peak of 29.9% after 8 hours.
An increase in pOBF was seen since day 1 of treatment which was
consistent throughout.
26.1
29.98
15.72
-21.51
-23.46
-14.86
-40
-30
-20
-10
0
10
20
30
40
4 8 12
pOBF IOP
Time (h)
%
Change
Clinical Therapeutics,2001,23(9),1519-1528
15. Aim: To evaluate the efficacy of topical brimonidine in visual
field preservation and / or improvement in eyes
undergoing controlled glaucoma
No. of Patients: 70 eyes of patients were checked for
improvements in visual field following 2-4 months of
brimonidine treatment
Conclusion: Brimonidine may prevent visual field loss in
patients with glaucoma. It is possible that the
neuroprotective qualities of brimonidine may contribute to
visual field preservation in glaucomatous eyes.
16. • RGC survival increased
• Brimonidine and not timolol exhibit neuroprotective
effects
• Brimonidine increases pOBF
• Brimonidine increases the visual field
