Melatonin Glaucoma and Sleep

In my prior article, I referenced a study that made these conclusions (I paraphrase):

These findings strongly support a significant role for the neurotransmitter glutamate in the optic nerve damage characteristic of glaucoma. Present results suggest that an excessive increase in glutamate levels could represent an initial (and probably reversible) insult responsible for initiation of damage that is followed by a slower secondary degeneration that ultimately result in optic nerve cell death.

Although ocular hypertension is probably the most important risk factor in glaucoma, several other factors may significantly contribute to the optic nerve damage that is the real concern in glaucoma. In a previous report, we showed that free radicals in the eye might be involved in optic nerve cell death. Other authors have postulated that excessive levels of nitric oxide may contribute to this optic nerve damage.

A therapy that prevents the death of optic nerve cells is the main goal of treatment, although the current management of glaucoma is mainly directed at the IOP control.

On the basis of these and previous results, the following treatment strategies for glaucoma make sense:

  • prevent or control excess glutamate
  • control oxidation within the eye using antioxidants
  • decrease nitric oxide levels in the eye
  • preferably, use a combination of the above

This may represent a therapeutic strategy to prevent optic nerve cell death in glaucoma.

Several lines of evidence support that melatonin is an effective retinal antioxidant. Consider the following:

  • Retinal melatonin levels are significantly decreased in eyes with elevated IOP (hypertensive eyes).
  • It has been shown that melatonin is a potent inhibitor of the biochemical pathway that produces nitric oxide
  • Melaton inincreases glutamate uptake and glutamine synthetase activity and decreases glutaminase activity in the hamster retina, thereby helping control excess gluatmate.

Taken together, these results suggest that a treatment with melatonin could be a valuable resource in the management of glaucoma since melatonin, by itself, may exhibit positive influence on all three treatment strategies we suggested:

  • antioxidant (control of free radicals)
  • antinitridergic (control of nitric oxide) 
  • increase retinal glutamate clearance (control of excess glutamate)

My View

Given that I already expressed reluctance to be a guinea pig and evaluate the long term safety of melatonin on myself, where does that leave me?

My current strategy, in regard to the issues discussed above, is as follows:

  1. Eat plenty of fresh, organic fruits and vegetables and take traditional herbal supplements that are known to be excellent antioxidants to control free radicals. (I have discussed this often in prior articles.)
  2. Increase melatonin naturally by use of the ayurvedic daily routine (aka, dinacharya or dina charya - see here and here). There are a several key components of the daily routine strategy of interest in this article.
    1. I believe that going to bed early and at the same time each night will help the body produce the maximum amount of melatonin each day. I say this because I know of other research where another hormone (human growth hormone), which is similarly tied to the circadian rhythm, could be completed disrupted (where daily output was dramatically reduced) simply by not sleeping at a certain time of the night.
    2. I endorse the "cleanse the senses" strategy of the ayurvedic daily routine. I have recently started performing the triphala eye wash, as recommended.
    3. The oil massage as well as the regularity of the schedule can reduce stress hormones (glucocorticoids), which are known to raise IOP.
    4. Exposure to natural sunlight each day will further help regulate the body's natural cycle of producing melatonin. In the ayurvedic routine, a gentle early morning exercise facing the direction of the sun is often recommended.

I would prefer to let my body maximize its own production of melatonin by doing the things that trigger such production. The bottom line for me is that sleeping well, going to bed early, going to bed at the same time each night, and getting outside in the sun each day are probably some of the best things I can do for my vision. Each of these activities should help my body naturally maximize melatonin.

Here is one other view on how to increase melatonin naturally.