Symptoms of Amebic Keratitis

Amebic keratitis is a new corneal infection caused by infection with Acanthamoeba. Many people do not understand amoebic keratitis. The symptoms of amoebic keratitis are also quite obvious, and patients may experience symptoms such as blurred vision.

1. Superficial punctate keratitis (SPK)

The initial manifestations are SPK or subepithelial infiltration similar to herpes simplex keratitis (HSK) with coarse dots, dendritic infiltration, or small vesicular lesions and map-like epithelial defects.

2. Stromal Keratitis

It presents as paracentral discoid or annular corneal stromal infiltration, with the corresponding corneal epithelium remaining intact, which can be easily confused with discoid stromal keratitis caused by HSK. The key point of differentiation is that KP can be seen in HSK, but there is absolutely no KP in AK; in HSK, the corneal sensation is completely reduced, while in AK, only the central part is reduced and the peripheral part is increased.

3. Purulent corneal ulcer

When the lesion worsens further, purulent corneal ulcer or corneal stromal abscess (with intact epithelium) may form, and may lead to bulging of the posterior Descemet's membrane or corneal perforation. AK is rarely associated with corneal neovascularization.

4. Radial keratitis

Radial keratitis may occur in some cases and is a characteristic sign of AK. It manifests as radial cell infiltration from the corneal edge to the center of the cornea along the course of the corneal nerves, and the corresponding corneal epithelium remains intact. This can explain why the severity of corneal hypoesthesia and eye pain in this disease is inconsistent with the clinical manifestations.

5. Scleritis

This disease may be associated with diffuse or nodular scleritis.

6. Others

Patients experience a foreign body sensation, blurred vision, tearing, photophobia, and often severe pain. Most cases have a slow course, which may last for several months, while a few may develop into typical symptoms within a few days.