Perhaps it is for the same reason that Pharmac is beginning to receive attention (not of the positive variety) for its approach to medicating the people of New Zealand. Ethically, it is a dilemma that is only too familiar for politicians worldwide who serve an ageing population, particularly in countries with a ‘baby boom’ bulge such as Australia and New Zealand.
Trabecular bypass stents (Glaukos iStent, iStent Inject and Ivantis Hydrus) are a group of very low risk devices that bypass the trabecular meshwork and thus have the potential to reduce intraocular pressures (IOPs) to a level close or equal to episcleral venous pressure - around 14mmHg. Efficacy data supports this is a long-term effect in most cases as there is a minimal healing response. This differs from other aqueous/conjunctival shunts which are hampered by healing, just as we experience in trabeculectomy.
Multiple studies (see references below) have shown efficacy both in terms of IOP reduction but also with a decrease in medication load. This later aspect of care should not be underestimated. Not only do we miss opportunity for adequate treatment of IOP lowering due to poor compliance and adherence, but by reducing medication load we can also have a tangible influence on patient wellbeing, reducing the possibility for falls (beta blockers) but also limiting the devastating effect of prostaglandin-related orbitopathy. The unwanted adnexal effects of prostaglandin analogues not only cause an unsightly appearance but may also permanently alter lid and ocular function leading to potentially sight-threatening complications and should not be underestimated.
