Why is glycopyrrolate contraindicated if narrow angle glaucoma?

Dilation: Glucopyrrolate has a dilating effect on the eyes which can worsen the symptoms of glaucoma by increasing the pressure in the eye.

Open angles are okay: Glycopyrrolate is an anticholinergic, which has a potential effect on patients with NARROW angle glaucoma. The effects can transiently dilate the pupil, which in turn can congest the angle where the natural drainage system is. This effect can be too much in a narrow angle eye where the angle is already compromised. This can lead to acutely increased eye pressures and worsen glaucoma. Good luck!