Observation of Retrocorneal Plaques in Patients With Infectious Keratitis Using Anterior Segment Optical Coherence Tomography

Purpose: Endothelial plaques are a typical characteristic in patients with fungal keratitis. However, bacterial keratitis and herpetic keratouveitis are rarely associated with fibrin formation on the retrocorneal surface. This study was conducted to examine plaques attached to the endothelium in patients with infectious keratitis using anterior segment optical coherence tomography (AS-OCT). Methods: Seventeen patients (10 women and 7 men; mean age, 75 ± 15.5 years) suspected to have infectious keratitis with retrocorneal plaques were included. AS-OCT was used to acquire a scan of the retrocorneal plaque at the patient's first visit. Results: Based on the culture results and detection of viral DNA, the patients were diagnosed with fungal keratitis (6 patients), bacterial keratitis (8 patients), and herpetic keratouveitis (3 patients). Examination of the cornea using AS-OCT showed a clear boundary between the corneal endothelial surface and plaque in 8 patients with bacterial keratitis and in all patients with herpetic keratitis. Moreover, a space between the corneal endothelial surface and plaque was found in 3 patients with bacterial keratitis. In 5 patients with fungal keratitis, the AS-OCT images showed an unclear boundary between the corneal endothelial surface and plaque, and high reflection of the plaque was extended from the corneal lesion. Conclusions: Endothelial plaques in patients with fungal keratitis could continue from the corneal lesion. Observation of retrocorneal plaques using AS-OCT could be used in the diagnosis of infectious keratitis.