bubble_chart Overview

Episcleritis is located anterior to the equator and is particularly common in the area between the corneal limbus and the rectus muscle attachment. The disease course is short, prone to recurrence, and has a good prognosis. About two-thirds of patients have unilateral involvement, and it is commonly seen in adults. Clinically, it often presents in two types.

bubble_chart Clinical Manifestations

1. Nodular episcleritis: Nodular episcleritis is a type of episcleritis characterized by localized nodules and is the most common form. The cause of the disease remains unclear, but it is often associated with collagen diseases such as rheumatoid arthritis or erythema nodosum. The course of the disease is slow, with a tendency to recur.

The onset is usually acute, with symptoms such as eye redness, pain, photophobia, tenderness, and tearing. Near the corneal margin, especially on the temporal side, pink or purplish-red nodules appear due to extreme dilation of deep vessels in the superficial layer of the iris. The redness results from the dilation of superficial conjunctival vessels over the lesion. The nodules may be round or oval, and the overlying conjunctiva can be moved freely. Painful nodules are bright red, while subcutaneous nodules have a yellowish apex. In viral infections, nodules are often less distinct. In suppurative metastatic episcleritis, the nodules contain pus and may feel fluctuant upon palpation; touching the nodules usually causes pain due to irritation of the ciliary ganglion. The conjunctiva over the nodules shows congestion and edema, while the surrounding conjunctiva appears normal. The disease is self-limiting, lasting about two weeks. The nodules turn grayish-white, gradually flatten, and eventually resolve completely, leaving a depressed, grayish-black area that may adhere to the conjunctiva. Recurrences can occur elsewhere and may persist for months or even years. Both eyes may be affected simultaneously. Since intraocular tissues are generally unaffected, vision remains unimpaired. In some cases, deeper involvement may lead to scleritis.

Histologically, the nodules consist of granulation tissue with areas of fibrinoid necrosis, surrounded by palisading fibroblasts and multinucleated giant cells.

2. Simple episcleritis: Simple episcleritis typically presents with sudden eye swelling and pain. The affected episcleral layer and conjunctiva show diffuse congestion and edema. It recurs periodically, with short episodes lasting hours or days. Recurrences may affect either eye or different locations but usually involve the anterior episclera without localized nodules. Occasionally, eye pain, photophobia, and transient myopia may occur due to spasms of the iris sphincter and ciliary muscles. During episodes, eyelid edema may be seen due to neurovascular reactivity, and severe cases may be accompanied by periodic migraines.

bubble_chart Treatment Measures

1. Nodular episcleritis: The course of the disease is self-limiting within about two weeks.

2. Simple superficial scleritis: Remove the disease cause and prevent recurrence. Current treatment mainly involves the local application of hormones, with systemic application if necessary. Oral sodium salicylate or indomethacin can be used for pain relief, along with ethylmorphine hydrochloride eye drops. Autologous blood therapy may be applied. For particularly stubborn cases, ⁹⁰ strontium or X-ray radiotherapy can be used.