Abstract
Purpose: :
To evaluate a new Scanning Endothelial Microscope and compare it to the standard Konan Non–Con Robo Specular Microscope.
Methods: :
Corneal endothelial micrographs taken with a Scanning Endothelial Microscope (SEM) from Nidek, Inc. (part of the Confoscan 4 confocal microscope) were compared with corneal endothelial images taken with the Non–Con Robo SP–8000 of 5 subjects, 10 eyes (aged 23–67 yrs) in the central and peripheral regions. The automatic and manual modes were used for the SEM evaluation and were compared to the center dot method used in the Non–Con Robo. Cell density (CD), coefficient of variation of cell size (CV), % hexagons, and the number of endothelial cells counted were determined.
Results: :
The overall central CD using the SEM microscope in the auto mode was 2496±116 cells/mm2 (mean ± SD), which was 5.6% lower than the 2643±203 cells/mm2 for the Non–Con Robo. The central CD using the SEM in the manual mode (fixed frame analysis) was 2627±216, which was 0.6% lower than the Robo. The CV and % hexagons using the SEM were 0.46±0.03 and 45±7 versus 0.30±0.03 and 68±5 for the Robo. The manual mode of the SEM does not give CV and % hexagon analysis. However, the SEM scanning microscope has the ability to visualize many more endothelial cells with a much larger field compared to the Non–Con Robo. The mean number of cells counted in the auto mode with the SEM was 372±115 versus 141±10 for the Robo. The mean number of cells counted in the manual mode using the SEM was 466±78 cells.
Conclusions: :
The SEM enables wide field micrographs to be obtained from the human corneal endothelium (up to 650 cells) for morphometric analysis. The manual mode of the SEM provides endothelial cell densities similar to the Non–con Robo specular microscope. Additionally, the SEM can be successful in obtaining photos of the peripheral corneal endothelial cells.
Keywords: cornea: endothelium • imaging/image analysis: clinical • microscopy: confocal/tunneling