Summary:
Aim: To compare results of classical and digital analysis of the corneal
endothelium.
Material and methods: We evaluated a group of 36 eyes with physiological
findings of the anterior segment of the eye; the average age of examined
persons was 32.8 years (SD ± 9.5). The examination was performed by means of
non-contact specular microscope SP 1000 TOPCON. The obtained finding was
evaluated by means of i) classical analysis, ii) automatic digital analysis, and iii)
revised digital analysis. The result of the classical analysis is the cellular
density (number of cells/mm2). The digital analysis is made possible by means
of the connection of the specular microscope with the computer program
IMAGENET. The Endothelial Analysis System evaluates furthermore the
coefficient of the cellular area variation (%), and the hexagonality (%). The
normality of the values’ distribution was evaluated by means of the test
Liliefors, subsequently the paired t-test or nonparametric Wilcoxon’s test were
used. Results: Comparing results of the automatic to the revised digital
analysis, statistically significant difference in all evaluated parameters was
found (P = 0.01). The average cells’ density calculated by means of classical
analysis (2643 ± 347) is by 3 % smaller than the value established by means of
revised digital analysis (2718 ± 330 cells/mm2). Regardless of that, no
statistically evident difference was found at the 1 % level of significance. In 13
cases the revised digital analysis showed lower values than the classical one,
whereas in 23 cases the overestimation by revised digital analysis up to 501
cells/mm2 was found. To complete the classical analysis or the automatic digital
analysis, it takes in average 7–8 minutes. The time needed to examine one
sample of endothelium using the revised digital analysis was in the examined
group 25–30 minutes. Conclusion: Although there is no statistically significant
difference (P = 0.01) between the revised digital analysis and the classical
analysis, and between both methods there is statistically significant
dependence (r = 0.82); it is necessary to consider their incomplete compatibility
in case of results’ interpretation in a single patient. The revised digital analysis
is rather more time consuming, but supplies more information about the status
of the endothelial single layer.
Key words:
endothelium, specular microscopy, cells’ density, hexagonality,
coefficient of variation
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