Infectious optic neuritis occurs when viruses, bacteria, fungi, or parasites invade the optic nerve and nearby retina. The infecting agent travels to the eye via the bloodstream. Rapid and sometimes severe loss of vision may occur. One or both eyes may be involved. Symptoms may also include pain and light sensitivity.
A complete eye examination, including dilation, is necessary to visualize the optic nerve and diagnose optic neuritis.
In addition, fluorescein angiography is useful to evaluate the severity of the infection and assess retinal, vascular, and optic nerve involvement.
Optical coherence tomography (OCT) may be used to detect thickening, swelling, or atrophy of the nerve.
Treatment involves eradicating the infecting organism. Systemic antibiotics, antivirals, and antifungals are usually effective.
Occasionally, intravitreal medicine is injected directly into the eye to treat the infection.
Steroids may be recommended to prevent further optic nerve damage.
With accurate diagnosis and effective treatment, most cases of infectious optic neuritis maintain or recover useful vision. In severe cases, vision loss may occur and sometimes be permanent.