Conditions

What is Behçet’s disease?

Behçet’s is a rare multisystem disease that causes inflammation of the blood vessels throughout the body, including the eye. The condition is more common in people coming from Mediterranean countries, Turkey, the Middle East, Japan and south-east Asia, and the onset is typically in the second to fourth decades of life.

Signs and symptoms depend on the parts of the body affected by the disease.

Ocular involvement usually occurs in up to 70-95% of patients with Behçet’s and manifests as bilateral uveitis, affecting the anterior and/or the posterior part of the eye.

The typical manifestations of ocular disease is retinal vasculitis, occurring when the inflammation affects the vessels of the retina, causing inflammation in the vitreous, macular oedema and occlusion of the blood vessels.

The severe and recurrent nature of the uveitis can lead to permanent and often irreversible ocular tissue damage and subsequently, visual loss.

Other common manifestations of Behçet’s include:

Mouth ulcers: painful ulcers affecting the mouth, the tongue and the throat
Genital ulcers: painful ulcers usually developing around the anus, the vulva or the scrotum
Skin lesions, including acne-like spots, red patches or raised, tender, red nodules, commonly developing on the lower legs (erythema nodosum);
Joint problems (arthritis), manifesting with joints swelling and pain

Brain problems, including double vision, difficulty hearing, dizziness, loss of balance, fainting, weakness or numbness in the arms or legs
Bowel issues, including abdominal pain, diarrhoea and blood in the stools, due to ulceration throughout the digestive tract
Blood cots (thrombosis), involving the superficial veins causing pain, warmth and tenderness, and the deep veins, causing pain and swelling of the affected area (usually the limbs, most commonly the legs), and the arteries

What causes Behçet’s?

Behçet’s is an inflammatory condition presumably driven by an abnormal immune response that occurs in genetically predisposed individuals. It’s possible that a viral or bacterial infection may trigger the disorder.

Signs and symptoms of the disease are due to the inflammation of the blood vessels throughout the body.

Behçet’s syndrome can’t be passed on to other people or from parent to child, but genetic factors may increase the likelihood of a person developing the condition. The human leukocyte antigen (HLA)-B51 has been associated with the disease, but it is not used as a diagnostic test.

What are the symptoms of ocular disease?

Symptoms include

Diagnosis

The diagnosis of Behçet’s is based on clinical criteria, including recurrent oral ulcers, recurrent genital ulcers, ocular lesions and cutaneous lesions. Mouth ulcers are quite common in the population and if patients only have occasional mouth ulcers, it’s very unlikely that they have Behçet’s. There are no specific laboratory tests.

In patients with ocular manifestations, fluorescein angiography is usually performed to demonstrate inflammation of the retinal vessels and areas of vascular occlusion, to monitor the course of the disease and its complications and to evaluate the response to treatment.

Treatment

The intention of therapy is to control the inflammation and prevent the damage to the retina, and consequently the visual loss.

The treatments are not curative but aim at controlling the immune response which is the reason of the inflammation in the eye.

Options include the use of oral medications, usually starting with systemic steroids to induce rapid response. In view of the nature of the disease, the addition of immunosuppressive drugs is important to allow long term control and minimize the side effects of systemic steroids.

Local therapy is an option for controlling ocular disease and includes the use of steroid devices (Ozurdex and Iluvien).

Complications and Prognosis

If not well controlled, Behçet’s can result in long term damage because of the chronic macular oedema, optic nerve involvement and loss of retinal tissue.

Other common complications include abnormal retinal vessels that can bleed and epiretinal membrane. All these complications can affect the vision.

Behçet’s disease. Optos colour image showing multiple whitish retinal infiltrates and retinal vasculitis, causing inflammation in the vitreous and occlusion of the blood vessels.