Episcleral injection is suggestive of which type of conditions?

Episcleral injection refers to the prominence of the blood vessels on the episclera, the thin layer of tissue between the conjunctiva and the sclera. This condition indicates underlying inflammation or irritation in the eye, often linked to deeper ocular diseases. When episcleral vessels become dilated and prominent, it suggests that there is a more severe problem occurring than a surface issue.

Deep ocular diseases can involve structures such as the choroid, retina, or the anterior segment of the eye. Conditions like uveitis or keratitis may lead to episcleral injection as the inflammation spreads from these deeper regions. This distinguishes it from other types of conditions, which may not result in the same degree of vascular response visible through the episclera.

In contrast, allergic conditions and superficial infections usually manifest with conjunctival injection, where the vessels of the conjunctiva (the outermost layer of the eye) become engorged rather than the deeper episcleral vessels. Foreign body irritation typically also presents with more localized signs rather than widespread episcleral change.