Optic neuritis (new-RIGH-tis) is an inflammation of the optic nerve, the nerve that transmits every visual impulse from the eye to the brain. When the optic nerve becomes inflamed, it causes a marked decrease in central or fine visual acuity (uh-CUE-ih-tee), or a loss of visual field. Other symptoms include pain or tenderness of the eyeball, caused when the eye muscles pull or rub on the sheath surrounding the nerve. If you have optic neuritis, it may be difficult to see straight ahead. Colors may appear washed out, lights seem dim, and you may also have trouble with depth perception. Any activity that raises your body temperature, such as exercise or a shower, can make your vision problems worse. Proper diagnosis can only be made by a medical doctor during a thorough eye examination. Special lab and X-ray tests may need to be performed, including an MRI (M-R-I), to determine whether there's an underlying disorder causing the problem. In many cases, no specific cause for the inflammation is discovered. Some viral illnesses, bacterial infections, sinus infections, and inflammations in other parts of the body can also affect the optic nerve. In addition, because the optic nerve is an extension of the brain, it seems to be susceptible to some brain disorders, such as multiple sclerosis. Up to 95 percent of people who develop M.S. (M-S) will have an episode of optic neuritis at least once. Treatment of optic neuritis used to include the use of steroids, but it was found that steroids didn't significantly improve vision or lower the odds of recurrence. One positive note is that most people who have an episode of optic neuritis regain useful vision and never suffer another episode.
