Exposure keratitis refers to corneal inflammation caused by the cornea losing the protective function of the eyelids and being exposed to air, leading to dryness, epithelial erosion, and secondary infection. Common causes of exposure include eyelid defects, proptosis, ectropion, postsurgical upper eyelid retraction, or incomplete eyelid closure. It may also be observed in conditions such as facial nerve paralysis, deep anesthesia, or coma.
Clinical Manifestations
The lesion often involves the lower third of the cornea. In the early stages, the corneal and conjunctival epithelium becomes dry and rough, with conjunctival hyperemia and thickening in the exposed regions. Corneal epithelial defects progress from punctate erosions to larger, confluent areas, often accompanied by the formation of neovascularization. Secondary infection leads to symptoms and signs of suppurative corneal ulceration.
Figure 1 Exposure keratitis
Patchy epithelial defects can be observed on the cornea, accompanied by the formation of neovascularization near the lesion.
Treatment
The goal of treatment focuses on eliminating the exposure factors, protecting the corneal epithelium, and maintaining ocular surface hydration. Eyelid defect repairs, skin grafts, or eyelid reconstruction procedures are applied based on the underlying cause of the exposure. In cases of significant eyelid closure insufficiency caused by procedures like upper eyelid retraction surgery, further corrective surgery may be necessary to restore eyelid closure. The use of antibiotic ointments at night helps prevent infection, and the formation of an artificial moisture chamber provides additional corneal protection. Other measures are similar to those used in the management of neuroparalytic keratitis.