Summary of study design Patients will be randomised to one of 2 trial arms: 'laser-pathway' or 'medicine- pathway'. Following initial treatment, SLT patients will be followed up 1-2 weeks after treatment to check IOP and for potential side effects. The interval of subsequent follow-up visits (between 4 and 12 months) will be governed by the level of IOP in relation to the target IOP and the severity of glaucoma. Visual field testing (SITA standard, 24-2 test pattern) and imaging with the Hedidelberg Retina Tomograph (HRT III) will be performed at each visit. Target IOP will be set using the Canadian Glaucoma Society guidelines depending on the severity of glaucoma and the level of IOP. At subsequent visits, treatment will be escalated if the target IOP is not met or if there is evidence of progression.