[Chameleon-Like Corneal Disorders: Acanthamoeba Keratitis]

Area of Science:

• Ophthalmology
• Infectious Diseases
• Microbiology

Background:

• Acanthamoeba keratitis (AK) is a severe microbial keratitis, often presenting with varied clinical signs.
• The "chameleon" nature of AK complicates early and accurate diagnosis.
• Prompt diagnosis and treatment are crucial to prevent vision loss.

Purpose of the Study:

• To highlight the diverse clinical presentations of Acanthamoeba keratitis.
• To emphasize the diagnostic methods for confirming AK.
• To discuss the role of in vivo confocal microscopy in early AK detection.

Main Methods:

• Review of classical and atypical clinical signs of AK.
• Description of confirmatory diagnostic techniques: polymerase chain reaction (PCR), in vitro culture, and histopathological examination.
• Evaluation of in vivo confocal microscopy as a non-invasive diagnostic tool.

Main Results:

• Classical signs include greyish epithelial changes, perineuritis, and stromal infiltrates (multifocal or ring patterns).
• Laboratory confirmation is essential when clinical suspicion is high.
• In vivo confocal microscopy provides rapid, non-invasive visualization of Acanthamoeba.

Conclusions:

• Acanthamoeba keratitis requires a high index of suspicion due to its varied presentation.
• A combination of clinical evaluation and laboratory confirmation is necessary for definitive diagnosis.
• In vivo confocal microscopy is a valuable adjunct for early, non-invasive diagnosis of AK.