Open angle glaucoma and cholinergic drugs

[yoyohomieg5432]

I don't understand how cholinergic drugs are helping in the case of open angle glaucoma. Normaly they constrict the pupil which helps open up the canal but I thought that only helps in the case of closed angle?

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[debeer22]

cholinergic agonists (M3; e.g. pilocarpine) increase outflow of aqueous humor through opening meshwork (non-uveoscleral). Second to that will produce miosis

 

[jqueb29]

They constrict the pupil and open up the meshwork. Pupil constriction is what helps in closed angle, while meshwork opening is what helps in open angle.

 

[DrPicard]

cholinergic agonist --> ciliary muscle contracts --> trabecular meshwork opens up --> increased outflow

Theres a diagram somewhere in FA that shows aqueous humor flow and the points where the various glaucoma drugs act.

 

[yoyohomieg5432]

ok so i was thinking that the purpose of pupil constriction was that it brought the iris away from the trabecular meshwork to open it up.. but there's actually 2 methods by which the cholinergics help... they do what i just mentioned AND open up the trabecular meshwork via a second mechanism? does it create a larger opening in the mesh for more to leak through?