An Omics Approach to Diagnosing or Investigating Fungal Keratitis

Abstract

Fungal keratitis (FK) is one of the most severe corneal infectious diseases. FK often leads to poor visual prognosis and thus requires accurate diagnosis. Conventional approaches, including clinical diagnoses, smears, and cultures, often fail to provide reliable diagnostic value. Omics approaches, such as those using genomic, metagenomic, and tear proteomic data sources, provide promising features for improving the diagnosis and monitoring the progression of FK. Genomic approaches are based mainly on detecting amplicons of ribosomal RNA genes, and internal transcribed spacers are gradually gaining popularity in clinical practices. A metagenomic approach based on 16S rRNA genes may help monitor the dynamic change of conjunctival microbiota associated with an FK event, whereas that based on shot-gun and 18S rRNA target enrichment sequencing could have the potential to diagnose FK using clinical samples. A tear proteomic approach may provide comprehensive information about ocular surface defense and injury during FK. Representative up- and down-regulated proteins during FK could also be used as biomarkers to determine the clinical course and develop a treatment strategy in different stages of FK. Consequently, a personalized tear proteomic approach will soon play a key role in FK management.

16S Ribosomal RNA PCR Versus Conventional Diagnostic Culture in the Investigation of Suspected Bacterial Keratitis

“…Internal transcribed spacer (ITS), 28S rRNA, and 18S rRNA PCR have all been demonstrated to increase fungal detection rate in culture-negative cases and fungal PCR would be a useful adjunct to culture. 36 – 38 Multiplex real-time PCR assays are also being increasingly used for the diagnosis of viral keratitis. 39 Until newer techniques, such as shotgun metagenomics, become more clinically interpretable and cost effective, a PCR assay that combines broad range primers for bacterial, fungal, and viral detection is an interesting avenue that would allow rapid detection in keratitis cases where the diagnosis is not clear or when the keratitis is polymicrobial.…”

A deep learning approach in diagnosing fungal keratitis based on corneal photographs

“…Since most eye care practitioners are inexperienced with FK, delayed diagnosis is common and early morphological features are easily missed, resulting in poor clinical diagnosis. Therefore, many on-demand laboratory tests are being developed to increase the diagnostic accuracy of FK 27 . Corneal scrapes for direct microscopy and microbial culture are commonly applied in medical referral centers but often results in low sensitivity due to inadequacy of tissue sampling, examination by novice examiners, and confrontation of fastidious microorganisms 28 , 29 .…”

Inhibition of miR-665-3p Enhances Autophagy and Alleviates Inflammation inFusarium solani-Induced Keratitis

“…narrow antimicrobial spectrum and poor water solubility) are associated with the prognosis of FK. 4 , 5 In addition, the incidence of corneal perforation is still high and requires accurate diagnosis and proper treatment. 6 To date, the pathogenesis of FK has not been clearly elucidated.…”