Characteristics of In Vitro Culture and In Vivo Confocal Microscopy in Patients with Fungal Keratitis in a Tertiary Referral Hospital in Central China

Abstract

Purpose: To investigate the characteristics of in vitro culture and in vivo confocal microscopy (IVCM) in patients with fungal keratitis (FK) presented in a tertiary referral hospital in central China. Methods: In this noncomparative retrospective study, patients with the diagnosis of FK between October 2021 and November 2022 were reviewed. An IVCM and fungal culture (corneal scraping specimens) were performed, and the characteristics were analyzed. Results: During October 2021 and November 2022, 85 patients were diagnosed with FK. From 63 culture-positive cases, 8 species of fungus were identified. The proportions of isolated fungal species were Fusarium and Aspergillus equally accounting for 33.3% (21 of 63), Alternaria 9.5% (6 of 63), Curvularia 6.3% (4 of 63), Scedosporium apiospermum 6.3% (4 of 63), Paecilomyces lilacinus 3.2% (2 of 63), Exserohilum 3.2% (2 of 63), and Candida 4.8% (3 of 63), respectively. In positive culture cases, IVCM was found to be positive for hyphae or spores in 61 of 63 patients (96.8%). Different fungal species had a variety of cultural characteristics and IVCM manifestations. Conclusions: In a tertiary referral hospital in central China, Fusarium species, Aspergillus species, and Alternaria species were the 3 most common isolated fungal pathogens, and the proportion of Aspergillus species was significantly higher than that in other regions of China. Careful lesion depth examination by IVCM and OCT should be taken before lamellar keratoplasty to avoid postoperative recurrence. Identifying the IVCM image and culture characteristics will facilitate rapid diagnosis and proper treatment, but IVCM cannot yet replace fungal cultures to distinguish between different fungal species.

Botryosphaeria dothidea Mycotic Keratitis: A Novel Phytopathogen Causing Human Infection

“…By contrast, the use of IVCM enabled a rapid diagnosis of mycotic keratitis and facilitated the immediate implementation of antifungal treatment, which is essential to the prognosis of mycotic keratitis. 13,14 NGS further aided in the rapid identification of the phytopathogen, providing a quick diagnosis within 33 hours. NGS is a technology used for determining the sequence of nucleotides in entire genomes or targeted regions of DNA or RNA.…”

Differential expression of antimicrobial peptides in human fungal keratitis

“…DISCUSSION FK is a serious public health problem affecting the agricultural poor and therefore requires special attention. High rates of corneal perforation have been reported in cases of FK, although the progression of FK is slower compared to bacterial keratitis [3][4][5] . Due to the limited available treatments, there is an urgent need to study the mechanism of host immune response to fungal infections in order to find new treatments.…”

“…F ungal keratitis (FK) is a serious infection of the cornea that can lead to irreversible vision loss, with approximately 100 000 eyeballs were removed worldwide per year [1][2][3][4][5] . The current challenges are poor treatment response due to a number of factors, such as difficulty in microbiological identification, inadequate efficacy and permeability of antifungal drugs, and extremely wide drug sensitivity of existing drugs [6][7][8][9] .…”

Medical Imaging and Image Processing

“…MI is now becoming essential in different biomedical research and clinical practice fields. Biologists study cells and generate 3D confocal microscopy data sets [11]. Neuroscientists detect regional metabolic brain activity from positron emission tomography (PET) [12,13], functional magnetic resonance imaging (fMRI), and magnetic resonance spectrum imaging (MRSI) [14] scans.…”