Figure 4. Correlation of conjunctival inflammatory cell densities between in vivo confocal microscopy and brush cytology. Note that a significant positive linear correlation was found between in vivo confocal microscopy and brush cytology inflammatory cell densities. Pearson’s correlation coefficient r=0.97, p<0.0001. Note also that inflammatory cells densities in brush cytology specimens were relatively lower compared to the inflammatory cell densities in the corresponding in vivo confocal microscopy scans which might owe to destruction of some cells during staining and spin down. BC: brush cytology; ICD: inflammatory cell density.