Von Graefe's sign

Von Graefe's sign is a clinical sign in ophthalmology that is often associated with Graves' disease, a type of hyperthyroidism. It is named after the German ophthalmologist Albrecht von Graefe who first described it.

Description

Von Graefe's sign is characterized by a lag in the downward movement of the upper eyelid (known as eyelid lag) during downward gaze. This results in an abnormal widening of the palpebral fissure (the space between the upper and lower eyelids) during downward gaze. It is one of the most common signs of Graves' disease, but it can also be seen in other conditions that affect the extraocular muscles.

Pathophysiology

The pathophysiology of Von Graefe's sign is not completely understood. It is believed to be due to an imbalance in the function of the extraocular muscles, specifically the levator palpebrae superioris muscle and the superior rectus muscle. In Graves' disease, these muscles are often affected by the autoimmune process, leading to inflammation and fibrosis. This results in a restriction of the normal movement of the upper eyelid.

Clinical significance

Von Graefe's sign is a useful clinical sign in the diagnosis of Graves' disease. It is one of the earliest signs of the disease and is often present before other symptoms such as exophthalmos (protrusion of the eyes) and goiter (enlargement of the thyroid gland). However, it is not specific for Graves' disease and can be seen in other conditions that affect the extraocular muscles.

See also

• Graves' disease
• Eyelid lag
• Extraocular muscles
• Albrecht von Graefe