Dear GB: Glaucoma occurs when there is damage to the optic nerve, which carries visual information to the eye. This disease can develop without warning and can lead to gradual and permanent damage, including loss of some aspect of vision. Glaucoma is one of the leading causes of blindness, with approximately 3 million Americans affected.

As intimidating as it sounds, however, glaucoma can be diagnosed with a routine eye exam and, if caught early, treatment can help slow or prevent vision loss. Routine professional eye exams should be considered an essential part of health care.

When it comes to preventive nutritional approaches, I’m not aware of any “take this and you won’t get glaucoma” studies. However, research suggests that a healthy diet, supplemented with antioxidant nutrients, may be helpful. The often recommended complete plant-based diet is suitable because it offers the benefits of natural phytochemicals, nutrients and antioxidants.

It would also be prudent to have your recommended intake of the mineral magnesium. The logic here is that an inadequate supply of magnesium is associated with vasospasm: a spasm of the muscle layer that surrounds the blood vessels. The increase in vasospasm is implicated in several health problems, including glaucoma; this effect is probably due to vasospasm associated with impaired autoregulation of blood flow to the optic nerve.