Abstract
Purpose: :
Goldmann's applanation tonometry is still the gold standard for the measurement of intraocular pressure. Nevertheless various studies have shown its dependency from variations in corneal structural characteristics such as corneal thickness. The Dynamic Contour Tonometry (DCT) is a new method to determine intraocular pressure. It is supposed to be largely independent from corneal thickness. We wanted to check this by comparing the DCT measurements with direct intraocular readings.
Methods: :
In 7 patients scheduled for cataract surgery we simultaneously recorded 1) manometric IOP as determined by an infusion bottle connected to the anterior chamber,
2) intracameral IOP recorded by a pressure sensor, 3) Dynamic Contour Tonometry. Intraocular pressure was adjusted to 10, 20 and 30 mmHg by varying the height of the infusion bottle.
Results: :
We found a good correlation between the intraocular pressure and the results of the DCT (correlation coefficient of 0,97). Bland Altman analysis revealed a mean difference of 2.20 mmHg +/– 1.04 mmHg SD . This difference increased with higher values of the intraocular pressure. We found no dependency on corneal thickness.
Conclusions: :
Our results suggest that the Dynamic contour tonometry is an effective and accurate instrument to determine the intraocular pressure. It seems to be independent from corneal structural characteristics such as its thickness.
Keywords: intraocular pressure