Irritation and foreign body sensation or may be asymptomatic.

Critical

Corneal thinning, usually at the limbus, often in the shape of an ellipse, accompanied by an adjacent focal conjunctival or corneal elevation.

Other

Fluorescein pooling in the area but can stain. No infiltrate, no anterior chamber reaction, mild-to-moderate hyperemia.

See 4.23, Peripheral Corneal Thinning/Ulceration. 

Poor spread of the tear film over a focal area of cornea (with resultant stromal dehydration) due to an adjacent surface elevation (e.g., chemosis, conjunctival hemorrhage, filtering bleb, pterygium, tumor, and poststrabismus surgery).

1. History: Previous eye surgery? History of eye trauma?

2. Slit-lamp examination with fluorescein staining: look for an adjacent area of elevation.

1. Lubricating or antibiotic ophthalmic ointment every 2 to 4 hours and q.h.s. Temporary patching can be helpful in promoting corneal stromal rehydration in presence of excessive thinning.

2. If there is fluorescein staining rather than just pooling (use cotton-tipped applicator or tissue to wick away fluorescein to reveal potential underlying staining), treat as a corneal abrasion with antibiotic ophthalmic drops and ointment until the epithelial defect has resolved. See 3.3, Corneal Abrasion.

3. Treat the causative elevated lesion according to etiology. Surgical excision may be necessary.

4. If the cause cannot be removed (e.g., filtering bleb), lubricating ointment should be applied nightly, and viscous artificial tear drops should be used four to eight times per day. If drops are needed more than four times per day, a preservative-free drop should be used.

Unless there is severe thinning, reexamination can be performed in 1 to 7 days, at which time the cornea can be expected to be of normal thickness. If it is not, continue aggressive lubrication.