Assessment of size and nucleo-cytoplasmic characteristics of the squamous cells of the corneal epithelium

作者：Doughty Michael J^*

来源：Clinical and Experimental Optometry, 2015, 98(3): 218-223.

DOI：10.1111/cxo.12253

• corneal epithelium
• impression cytology
• morphometry
• N
• C ratio
• squamous cells
• transmission electron microscopy

PurposeThe aim was to objectively assess size, nucleus and nucleo-cytoplasmic ratio features of squamous cells from the corneal epithelium
MethodsThe corneas of recent post-mortem sheep eyes were either glutaraldehyde-fixed for transmission electron microscopy or impression cytology samples taken, glutaraldehyde-fixed and stained with Giemsa. From the specimens for impression cytology, a representative region was photographed from 12 different samples taken from the central region and 16 different samples taken from mid-peripheral regions of the corneal epithelium. Images were subjected to morphometry after overlays were generated.
ResultsElectron microscopy revealed a very distinctive stratified corneal epithelium with several superficial layers, confirming the squamous phenotype. Impression cytology from such superficial layers revealed a cell size of 60.1 4.8m, nucleus dimension of 12.3 +/- 1.5m, cell area of 2,419 +/- 416m(2) and nucleus area of 131 +/- 31m(2). A nucleo-cytoplasmic ratio based on nucleus-to-cell length had a mean of 0.207 +/- 0.022, while a cytoplasm-to-nucleus length ratio was 3.975 +/- 0.474. Estimates of the nucleo-cytoplasmic ratio based on areas had a mean value of 0.059 +/- 0.011. Very similar results were found for mid-peripheral corneal epithelium.
ConclusionsThe results strongly indicate that the squamous phenotype of the superficial corneal epithelial cells is characterised by a large size, large nucleus and low nucleo-cytoplasmic ratio. These morphological characteristics show a notable resemblance to data obtained from impression cytological studies on human conjunctival epithelial cells showing severe squamous metaplasia.

• 出版日期2015-5