- meditation (but only certain techniques)
- exercise (I agree with what Mary Beth said in her answer)
There are many more activities that could be listed, but your asked for the top three. Overall, stress management activities need to have high priority. We can benefit by this approach in selecting the best activities for managing their IOP.
I'll split this into two subsections:
Drug usage techniques:
- self-tonometry: it is nearly impossible to selection your optimal medication routine without the feedback of frequent IOP monitoring in real life. If you try a variety of eye drops and monitor the results, you will learn what works best for you.
- microdosing: background here
- consistency in usage: I find that self-tonometry is very helpful in ensuring my compliance with my medication routine
My personal approach is to use drops which are free of BAK. I agree with what Mary Beth said in her answer, but I will list three classes of glaucoma medications that deserve attention:
- rho kinase inhibitors such as netrasudil (Rhopressa)
- nitric oxide donors such as latanoprostene bunod (Vyzulta) (which doubles as a prostaglandin analog)
- prostaglandin analogs such as latanoprost, bimatoprost, travaprost, tafluprost)
Supplements for Reducing Intraocular Pressure
I am not able to limit this to just three items because supplements are synergistic. My experience is you need to combine several supplements to get results. I never saw any reduction in IOP when I tested supplements one at a time. But when I used all these listed together, I did see results. Also, specific supplements, like drugs, work better for some individuals compared to others.
- PEAmium (palmitoylethanolamide). Details given in this answer.
- Rutin plus coleus forskohlii
- oligomeric proanthocyanidins source (such as pine bark extract or grape seed extract) plus berry extracts, especially bilberry. I prefer grape seed extract plus this bilberry extract. Another good combination is Mirtogenol (which is pine bark extract plus bilberry).
- astragalus - Astragalus showed the ability to significantly lower eye pressure (IOP) in a study in Life Science Journal. This study claimed, "The extremely beneficial antioxidant effect of Astragalus in this glaucoma model may be equal to brimonidine, a standard glaucoma medication." source
- melatonin - details given in this answer and here.
- L-citrulline and/or beet root extract (nitric oxide donors) - theoretical only. I don't know of direct evidence of IOP reduction for citrulline yet, but given the proven benefits of other nitric oxide donors, plus the suggestion that glaucoma patients may be deficient in nitric oxide production lands this supplement on my experimental list.
There are other very important supplements for glaucoma, but you asked specifically about IOP. The broader glaucoma supplement list should include omega-3 oils, carotendoids, mushrooms, maqui berry, amla, saffron, citicoline, TUDCA, vitamin C, ginkgo, B3 as nicotinamide/niacinamide, ubiquinol, NAC, and many others.