Melatonin keeps your body on schedule, maintaining your internal 24-hour clock and regulating hormones, including those associated with the reproductive system. Your body naturally produces melatonin, but levels drop as you age. Melatonin supplements may help treat macular degeneration, a leading cause of vision loss in people over 60, according to the National Eye Institute, but this has not been proven yet. Do not take melatonin to prevent or treat macular degeneration without talking with your doctor first.
Causes
Macular degeneration occurs when cells in the macula begin to thin and break down as you age, causing blurred vision. This condition, called dry macular degeneration, advances to wet macular degeneration in around 15 percent of people with dry macular degeneration. Wet macular degeneration occurs when abnormal blood vessels grow under the macula and leak fluid.
Melatonin Actions
Melatonin, in addition to keeping your internal clock ticking, also acts as an antioxidant. Antioxidants decrease free radicals, harmful substances formed from the breakdown of toxins that can damage cells. Melatonin may also protect the retinal pigment epithelium, the layer under the retina that controls the amount of light that reaches photoreceptors in the retina. Since melatonin levels decrease with age, and since breakdown in the retinal pigment epithelium contributes to macular degeneration, melatonin supplements may prevent macular degeneration.
Results
A 2005 Chinese study conducted by the Zhongshan Ophthalmic Center, Sun Yat-Sen University, found that giving patients with existing wet and dry macular degeneration 3 mg of melatonin daily reduced vision loss, which normally occurs in patients with the disease. Since this was a single study, more studies to confirm melatonin's benefits on the retina are needed.
Side Effects
If you take too much, melatonin can disrupt your internal clock. Melatonin can also cause vivid dreams or nightmares. You may become sleepy during the day. Other side effects include stomach cramping, headache, irritability and dizziness.
Warnings
Melatonin can cause serious problems, such as decreased sperm count in men, loss of libido and an increased risk of depression. In animal studies, melatonin reduced the effectiveness of antidepressant medications. Melatonin can also cause steroids and immunosuppressant medications to lose their effectiveness. Do not take melatonin without discussing its use with your physician first. Do not use melatonin as a substitute for medical treatment for macular degeneration, since irreversible vision loss can result without treatment.
