Purpose To evaluate efficacy and safety of combigan(Brimonidine/Timolol) and 0.5% Timoptic (Timolol) ophthalmic solutions in normal tension glaucoma patients.

• Normal tension glaucoma (NTG) is the major type of glaucoma in Korea. (over 90% of glaucoma type)
• Brimonidine (selective alpha 2 adrenergic agonist): neuroprotection effect by suppression of aqueous humor production and increasement of uveoscleral outflow
• Timolol (non selective beta blocker): suppression effect of aqueous humor production
• Combigan (fixed combination of brimonidine & timolol): more lowering effect of intraocular pressure and enhancing the compliance of glaucoma patients

Inclusion Criteria:

• over 18 years old
• baseline IOP under 22 mmHg,both anterior chamber angle > Grade 3~4 by Shaffer grading system

Exclusion Criteria:

• IOP over 22 mmHg by Goldmann applanation tonometer
• other types of glaucoma except open angle
• other IOP lowering treatment
• chronic or recurrent Hx. of ocular inflammation
• using contact lens
• any other ocular disease that could affect visual field examination (diabetic retinopathy, macular disease, uveitis, scleritis, optic neuritis, anterior ischemic optic neuropathy)
• intraocular or glaucoma surgery within 6 months
• Hx. of allergic reaction to timolol or brimonidine
• bronchial asthma
• moderate to severe chronic obstructive pulmonary disease
• heart failure
• 2~3 degree A-V block,
• MAO inhibitor use
• anti depressant use
• untreated pheochromocytoma
• pregnant