The combined use of in vivo confocal microscopy and optical coherence tomography in monitoring corneal infections

BACKGROUND/AIMS: Infectious keratitis (IK) is a major cause of blindness worldwide, requiring prompt diagnosis and management. This study evaluates the diagnostic and evaluative roles of in vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT) in acute IK through correlating the characteristic imaging features of both modalities. MATERIALS AND METHODS: In this prospective study, 35 eyes with severe IK of bacterial, fungal, Acanthamoeba, or mixed origin were examined using slit lamp biomicroscopy, microbiological culture, AS-OCT, and IVCM during the acute phase. Imaging parameters including tissue integrity, cellular infiltration, nerve presence, vascularisation, and microbial features were analysed. Quantitative cell density measurements and structural assessments were performed, with statistical comparisons between modalities and pathogen groups. RESULTS: IVCM effectively visualised cellular details, including keratocytes, inflammatory cells, nerve fibres, and specific organisms, with high sensitivity for detecting fungal filaments and Acanthamoeba cysts. AS-OCT provided high-resolution cross-sectional images, accurately measuring infiltrate depth, corneal thickness, and neovascularisation. IVCM was superior in identifying microbial elements, whereas AS-OCT excelled in assessing tissue architecture and oedema. Significant differences in cell densities were observed among pathogens, notably lower keratocyte density in Acanthamoeba keratitis. Both modalities were complementary, enhancing disease characterisation and monitoring. CONCLUSIONS: IVCM and AS-OCT are valuable, non-invasive tools that provide critical insights into IK. Their combined application improves early diagnosis, detailed evaluation, and treatment monitoring. Integration with artificial intelligence holds promise for further advances in precise, rapid diagnosis and personalised management of infectious keratitis.