In optic neuritis involving retrobulbar fibers, which statement is true about the optic nerve head appearance?

• A. The optic nerve head is always swollen
• B. The optic nerve head appears normal in all cases
• C. The optic nerve head MAY appear normal if the retrobulbar portion is affected
• D. The optic nerve head shows hemorrhages

Answer: (C)

In optic neuritis, where the inflammation is behind the eye (retrobulbar), swelling of the optic nerve head is not always visible because the affected portion is posterior to the globe. That’s why the optic nerve head can look normal even when vision is affected. The true statement is that the optic nerve head may appear normal if the retrobulbar portion is involved.

Context helps: patients often have sudden vision loss with eye movement pain, but the fundus exam can be normal in retrobulbar neuritis. If the inflammation extends to the front of the nerve (papillitis), then optic disc swelling may be seen, and the appearance would differ. Over time, prolonged damage can lead to pallor of the optic disc.

The other possibilities aren’t as accurate because swelling is not mandatory and can be absent in retrobulbar cases, and hemorrhages are not a typical feature of optic neuritis.