With a growing body of evidence to support its utility, confocal microscopy may one day leave the research lab and land in your office. The imaging modality has proven adept at documenting corneal cells, and a new study now shows it can help clinicians track treatment efficacy for Acanthamoeba keratitis (AK).1,2

Researchers in China used in vivo confocal microscopy to observe the morphology, distribution and density of Acanthamoeba cysts before and after medication in 37 patients. They found the imaging modality identified cysts 94.6% of the time, and showed several typical characteristics, such as a low light-reflective wall and a high-refractive nucleus. The cysts tended to cluster or create chains in the corneal stroma.2

Imaging patients after medical treatment showed the nuclei if the cysts dissolved, leaving hollow cysts that remained for up to six months. The researchers noted the number of cysts increased with one to two weeks of treatment in 62.1% of patients, but then began to dissipate in 35.1% of patients responding well to antiamoebic treatment.2

Confocal microscopy “may serve as a valuable tool to guide clinical evaluation and treatment of AK,” they concluded.2

This study helps to confirm research published earlier this year that found confocal microscopy    showed an average 5.3% reduction in cyst density with each month of AK treatment.3

1. Liu Y, Chou Y, Dong X, et al. Corneal subbasal nerve analysis using in vivo confocal microscopy in patients with dry eye: analysis and clinical correlations. Cornea. July 10, 2019. [Epub ahead of print].

2. Li S, Bian J, Wang Y, et al. Clinical features and serial changes of Acanthamoeba keratitis: an in vivo confocal microscopy study. Eye (London). July 10, 2019. [Epub ahead of print].

3. Wang YE, Tepelus TC, Gui W. Reduction of Acanthamoeba cyst density associated with treatment detected by in vivo confocal microscopy in Acanthamoeba keratitis. Cornea. 2019;38(4):463-68.