The influence of central corneal thickness and corneal biomechanics in glaucoma
Article first published online: 23 SEP 2010
2010 Acta Ophthalmologica
Special Issue: Abstracts from the 2010 European Association for Vision and Eye Research Conference
Volume 88, Issue Supplement s246, page 0, September 2010
How to Cite
LAM, F., LI YIM, J. and MONTGOMERY, D. (2010), The influence of central corneal thickness and corneal biomechanics in glaucoma. Acta Ophthalmologica, 88: 0. doi: 10.1111/j.1755-3768.2010.2352.x
- Issue published online: 23 SEP 2010
- Article first published online: 23 SEP 2010
- Cited By
Purpose To look at the impact that central corneal thickness and corneal biomechanics can have on intraocular pressure (IOP) measurements and their effect on visual fields.
Methods Written and informed consent from patients and guidance from the local research ethics committee was obtained. Ocular diagnoses and ocular medications were recorded. IOPs were recorded using Goldmann applanation tonometry (GAT)followed by dynamic contour tonometry with the Pascal tonometer. Central corneal thickness(CCT) was measured using ultrasound. Visual fields were recorded using Humphries perimetry. Bland-Altman plots were used to compare the 2 methods.
Results 92 eyes of 46 patients were included. Median CCT 556µm(range:427µm-634µm). Despite a good correlation of the IOP measurements usin the two different techniques(r=0.7; p< 0.01), there was a significant difference in limits of agreement(LOA) of DCT to GAT on the Bland-Altman analysis. The LOA was 8.6mmHg to -4.8mmHg with a mean bias of 1.9mmHg. This persisted even after correction for CCT. Ocular hypertensives had a wider LOA than glaucoma patients.
Conclusion DCT IOP measurements can be significantly different from GAT IOPs even after taking into account central corneal thickness. Compared to CCT, corneal hysteresis appears to have a greater impact on IOP measurements. This could have important prognostic implications.