A Study of Ganfort Versus Duotrav in Patients With Primary Open Angle Glaucoma or Ocular Hypertension

Inclusion Criteria: 1. Visual acuity 6/60 or better 2. Patients who are controlled (IOP \< 21 mmHg) on non-fixed combination of Latanoprost \& Timolol for at least 3 months before the baseline visit and 3. Patients on mono-therapy either Latanoprost or Timolol who are eligible for dual therapy being not satisfactorily controlled (IOP\>21mmHG) Exclusion Criteria: 1. Angle closure glaucoma 2. Neovascular Galucoma 3. Secondary open angle glaucoma 4. Ocular infection/inflammation within 3 months 5. Ocular surgery within 3 months 6. History of Refractive surgery 7. Argon laser trabeculoplasty/Selective laser trabeculoplasty 8. Pregnancy/nursing 9. Hypersensitivity to benzalkonium chloride or to any other components of the trial drugs solution. 10. Patients in whom beta-blockers are contraindicated 11. Patients on any drugs known to affect IOP.