Kocher's sign is characterized by globe lag compared to lid movement when looking up.

• A. Lid lag during downgaze
• B. Globe lag compared to lid movement when looking up
• C. Lid retraction with stare
• D. Infrequent blinking

Answer: (B)

Kocher's sign shows a restriction of eye movement with a visible lag of the globe as the patient looks upward. This occurs because in Graves’ ophthalmopathy the inferior rectus muscle often becomes fibrotic and tight, so the globe cannot rotate upward as readily as the eyelid can move. As the lid elevates smoothly, the globe lags behind, producing the characteristic lag you observe during upgaze. This distinguishes it from signs like lid lag in downgaze or lid retraction with uplift, which involve different mechanisms and presentations. So the description of globe lag behind the lid during upgaze is the defining feature.