Perhaps it goes without saying, but in glaucoma, those who don’t take their medicine run a higher risk of losing their vision than those who do. At the very least, the association—published in the latest issue of Ophthalmology—between non-compliance and blindness should help scare your patients into taking their prescribed regimen seriously.

Research associated with the Collaborative Initial Glaucoma Treatment Study (CIGTS) looked at 307 patients for nearly a decade, checking in once every six months. The researchers used self-reported medication adherence metrics and visual field tests.

Almost half—46%—reported never missing a dose, and their mean deviation over time was 0.62dB. That number is consistent with age-related field loss. Another 37% reported missing medications for up to a third of their visits. Their loss was a little higher at 1.42dB. Those who skipped their glaucoma drops between a third and two thirds of the time—10%—and the 7% who reported missing medication more than two thirds of the time had 2.23dB loss.

So, there it is, in black and white: worse medication adherence is associated with loss of mean deviation over time.