Clinical Sciences
Feasibility of confocal laser scanning microscopy with slit-lamp microscope in the diagnosis of filamentous fungal corneal infection with culture negative patients
Hongmin Zhang, Xinyan Dou, Ke Yang, Shengtao Sun, Lei Han, Jin Li, Xiaofei Yu, Liya Wang
Published 2018-02-10
Cite as Chin J Exp Ophthalmol, 2018, 36(2): 119-123. DOI: 10.3760/cma.j.issn.2095-0160.2018.02.009
Abstract
ObjectiveTo investigate the imaging manifestations of different filamentous fungal strains under the confocal laser scanning microscope and slit-lamp microscope, and evaluate the feasibility of rapid diagnosis and therapeutic efficacy judgment for fungal culture negative patients.
MethodsA diagnosis trail was performed.Nine hundred and ninety-three patients with fungal keratitis (FK) which were varified by fungal culture were included in Henan Eye Hospital from September 2013 to January 2014.Distribution of fungi strains and positive rate of fungal strains by fungal culture and corneal confocal laser scanning microscopy were compared.The imaging characteristics of different filamentous fungi and different stages of one filamentous fungi under the slit-lamp microscope and confocal laser scanning microscopy were summarized.
ResultsIn the 993 FK patients, the diagnostic positive rate of fungal culture and confocal laser scanning microscopy was 43.20% and 82.07%, respectively, showing a significant difference between them (χ2=45.323, P=0.000). In 429 culture-positive patients, the diagnostic positive rate of confocal laser scanning microscopy was 92.31%; while in 564 culture-negative patients, the diagnostic positive rate of confocal laser scanning microscopy was 74.29%.In 429 culture-positive patients, Aspergillus was the most common genus, accounting for 50.12%, and followed by Fusarium sp.and Altemaria sp. (18.18% and 10.49%). There were no significant differences in fungal species distributions between fungal culture and confocal laser scanning microscopy examination in 429 cases (all at P>0.05). The imaging characteristics under the slit-lamp microscope and confocal laser scanning microscope were different in different fungi stains.Aspergillus infection showed a plume-like corneal ulcer, and the Aspergillus sp.hyphae were thin and line-shaped with high reflective light and less branched under the confocal laser scanning microscope.Toothpaste-like corneal infiltrationwas seen in Fusarium sp.-infectiouslesions under the slit lamp microscope, and mycelium showed a high-reflective long rod-like image with less branch in the image of confocal laser scanning microscope.Alternaria alternate sp. corneal infection showed nevus lesions, and hyphae characterized by high-reflective long rod or string beads in shape with less branches in the image of confocal laser scanning microscope.The mycelium was ruptured, shorter, thinner with weak reflective light following drug therapy.The differential diagnosis could be easily obtained between hyphae and corneal nerve fibers by confocal laser scanning microscope.Hyphae intertwined, or had branches with diffuse distribution, which surrounded by high-reflective inflammatory cells and destructed matrix fiber and were located in stroma.The corneal nerve fibers located between epithelium layer and stroma layer, surrounded by normal epithelium or stroma structure.The diameter of the thicker nerve fibers in the stroma layer was obviously thicker than that of the hyphae.
ConclusionsThe diagnosis rate of confocal laser scanning microscope combined with slit-lamp microscope for filamentous fungi-infectious FK is higher than that of fungal culture.The combination procedure of confocal laser scanning microscope and slit lamp microscope examination provides a rapid evaluation for fungi strains and therapeutic efficacy in the FK patients with negative results by fungal culture.
Key words:
Keratitis, fungal/diagnosis; Fungi, filamentous; Confocal laser scanning microscope; Slit-lamp microscope
Contributor Information
Hongmin Zhang
Henan Eye Institute, Henan Eye Hospital, Henan Provincial Key Laboratory of Ophthalmology and Vision Science, People's Hospital of Henan Province, People's Hospital of Zhengzhou University, Zhengzhou 450003, China
Xinyan Dou
Ke Yang
Shengtao Sun
Lei Han
Jin Li
Xiaofei Yu
Liya Wang