Scleritis


Scleritis is a serious inflammatory disease that affects the white outer coating of the eye, known as the sclera. The disease is often contracted through association with other diseases of the body, such as granulomatosis with polyangiitis or rheumatoid arthritis. There are three types of scleritis: diffuse scleritis, nodular scleritis, and necrotizing scleritis. Scleritis may be the first symptom of onset of connective tissue disease.
Episcleritis is inflammation of the episclera, a less serious condition that seldom develops into scleritis.

Signs and symptoms

Symptoms of scleritis include:
The pain of episcleritis is less severe than in scleritis. In hyperemia, there is a visible increase in the blood flow to the sclera, which accounts for the redness of the eye. Unlike in conjunctivitis, this redness will not move with gentle pressure to the conjunctiva.

Complications

Secondary keratitis or uveitis may occur with scleritis. The most severe complications are associated with necrotizing scleritis.

Pathophysiology

Most of the time, scleritis is not caused by an infectious agent. Histopathological changes are that of a chronic granulomatous disorder, characterized by fibrinoid necrosis, infiltration by polymorphonuclear cells, lymphocytes, plasma cells and macrophages. The granuloma is surrounded by multinucleated epitheloid giant cells and new vessels, some of which may show evidence of vasculitis.

Diagnosis

Scleritis is best detected by examining the sclera in daylight; retracting the lids helps determine the extent of involvement. Other aspects of the eye exam may be normal. Scleritis may be differentiated from episcleritis by using phenylephrine or neosynephrine eye drops, which causes blanching of the blood vessels in episcleritis, but not in scleritis.
Ancillary tests CT scans, MRIs, and ultrasonographies can be helpful, but do not replace the physical examination.

Classification

Scleritis can be classified as anterior scleritis and posterior scleritis. Anterior scleritis is the most common variety, accounting for about 98% of the cases. It is of two types : Non-necrotising and necrotising. Non-necrotising scleritis is the most common, and is further classified into diffuse and nodular type based on morphology. Necrotising scleritis accounts for 13% of the cases. It can occur with or without inflammation.

Treatment

In very severe cases of necrotizing scleritis, eye surgery must be performed to repair damaged corneal tissue in the eye and preserve the patient's vision. For less severe cases, nonsteroidal anti-inflammatory drugs, such as ibuprofen, are prescribed for pain relief. Some patients also benefit from a course of Steroid eye drops such as Pred Forte Scleritis itself is treated with an oral medication containing corticosteroids and an eye solution. In some cases, antibiotics are prescribed. Simply using eye drops will not treat scleritis. In more aggressive cases of scleritis, chemotherapy may be used to treat the disease. If not treated, scleritis can cause blindness.

Epidemiology

Scleritis is not a common disease, although the exact prevalence and incidence are unknown. It is somewhat more common in women, and is most common in the fourth to sixth decades of life.