[In vivo imaging of the conjunctival epithelium using confocal laser scanning microscopy]

In various ocular diseases, cytomorphological findings of the ocular surface are an essential component of clinical diagnostics. When evaluating the conjunctival epithelium, minimally invasive acquisition of biomaterial is necessary for lab and technical processing and in vitro histological examination. To examine corneal structures in vivo, confocal laser scanning microscopy is a successful standard method. Our aim was to employ in vivo confocal laser scanning microscopy also for examining the conjunctival epithelium.

Results were analyzed and compared with cytomorphological findings of impression cytology. Accordingly, the basic features of conjunctival in vivo examination using RLSM were described and defined. In vivo images were analyzed and compared with impression cytological slide preparations (n=110) of 23 healthy test persons. Examination was standardized. Finally, the confocal laser scan images were compared to the impression cytological patterns.

Due to the distribution of reflectors (pixel brightness), diagnostic analysis of important morphological structures (cell nucleus, cytoplasm, nucleus/plasma relation) of the conjunctiva is possible. Secretory cells of the epithelium (goblet cells) can be easily recognized by their size. Highly reflective pixels depict cell walls or wide intercellular spaces with high contrast.

The in vivo investigation of important anatomical and morphological structures of the conjunctival epithelium is possible using RLSM. The distribution pattern of goblet cell pixel brightness may correlate with various secretion contents or suggest distinct, recognizable, functional conditions (hypo- or hypersecretion).