Understanding the influence of CPAP on IOP is important as it may inform the management of people with OSA and concomitant glaucoma. If CPAP is shown to raise IOP or alter OPP to levels that pose clinical risk it will be necessary to assess available alternative treatment options for OSA. If, however, CPAP does not alter these parameters, there would be a rationale for assessing long-term effects of CPAP, most probably in the form of a randomised interventional trial, informed by the findings of this research.