Development of a laser confocal endomicroscope for in vivo fluorescence imaging

Malignancies of the oral cavity are conventionally diagnosed by white light endoscopy, biopsy and histopathology. However, it is often difficult to distinguish between benign lesions and premalignant or early lesions. There is a need for a more definitive, non-invasive technique for diagnosis of oral cavity lesions. A laser confocal endomicroscope offers non-invasive surface and subsurface imaging of tissue. We investigated its potential for fluorescence imaging of the oral cavity using hypericin, fluorescein and aminole-vulinic acid. Fluorescence imaging was carried out both in vivo and on resected tissue samples of the oral cavity in both humans and animal models. Good structural images of the oral cavity were obtained. Morphological differences between normal and lesion tissue can be distinguished. The use of Pharmasolve (R) enhanced the subsurface depth from which images can be obtained. Our results show that laser confocal fluorescence endomicroscopy has great potential for the diagnosis of oral cavity malignancies.