Paton's lines temporal to the disc are most characteristic of which condition?

• A. Papilledema
• B. Optic neuritis
• C. Ischemic optic neuropathy
• D. Optic nerve glioma

Answer: (A)

Paton's lines are folds in the retinal nerve fiber layer that appear as fine, radiating or circinate lines around the optic disc. They arise from edema of the nerve fiber layer when intracranial pressure is elevated, causing axoplasmic flow stasis and swelling of the optic nerve head. When these folds extend temporally from the disc, they are particularly associated with papilledema.

This pattern helps distinguish papilledema from other optic neuropathies. In optic neuritis, you may see disc edema but not the characteristic RNFL folds; ischemic optic neuropathy shows sectoral pallor and sudden, often altitudinal field defects with different disc changes; optic nerve glioma presents with progressive, often unilateral swelling and other signs rather than this RNFL folding pattern. Therefore, the presence of Paton's lines temporal to the disc points most to papilledema due to raised intracranial pressure.