Artikel
Transpalpebral tonometry using TGDc01 in children aged 0 - 6 years, awake and under general anesthesia: comparison with Perkins tonometry and palpation of IOP
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Autoren
Veröffentlicht: | 22. September 2004 |
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Gliederung
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Objective
IOP measurement in children without general anesthesia is rather difficult. Usually, palpation of the IOP is used for this purpose despite limitations in reliability. Transpalpebral tonometry could serve this demand because measurements are painless and can be performed within seconds without local anesthesia. Purpose of this study was to evaluate deviations between TGDc01 tonometry and palpation of IOP without general anesthesia as well as between TGDc01 based and Perkins tonometry under general anesthesia in children aged 0 - 6 years.
Methods
A total of 30 eyes of 15 children aged 0 - 6 years were included. The first examination was performed without general anesthesia, the second examination within 3 days under routinely planed general anesthesia. Each tonometry method was performed by an independent observer: observer 1 took three replicate IOP measurements in each child using TGDc01 tonometry with and without general anesthesia, observer 2 measured the IOP via palpation without general anesthesia and observer 3 took three replicate measurements using Perkins tonometry under general anesthesia. Intraindividual deviations between measurement results were investigated concerning clinically relevance by comparison of medians and quartiles, concerning statistically significance by sign tests; p-values < 0.05 indicate local statistical significance.
Results
Median age of the children was 3 years (interqartile range 2 - 5). There were no measurement failures, neither with nor without general anesthesia. TGDc01 based tonometry demonstrated significantly lower IOP values than palpation of IOP (TGDc01-palpation: median difference -1,5 mmHg (interquartile range -4,0 ; -0,4, p=0,002) and Perkins tonometry (TGDc01 - Perkins: median difference -1,8 mmHg (-3,5 ; -0,3, p=0,003). 53% of the deviations between TGDc01 and Perkins based tonometry, and 42% of the differences between TGDc01 tonometry and palpation of the IOP exceeded a clinically tolerable difference of ±2 mmHg.
Conclusions
TGDc01 based tonometry is a feasible method for IOP measurement in children without general anesthesia, but underestimation of IOP has to be considered compared to Perkins tonometry and palpation of the IOP. The degree of underestimation increases with increasing IOP.