The influence of soft contact lenses on the intraocular pressure measurement

Purpose To evaluate the influence of silicone hydrogel contact lenses on the intraocular pressure (IOP) measurement using Goldmann applanation tonometry (GAT), non-contact tonometry (NCT), and Pascal dynamic contour tonometry (DCT). Methods We included in the study 40 eyes of 40 patients who did not have any ocular or systemic diseases or contraindications to contact lens use. We measured and recorded the IOP values of each patient using NCT without and with contact lenses (groups 1 and 2, respectively), using DCT without and with contact lenses (groups 3 and 4, respectively), and using GAT without contact lenses (group 5). Results The mean IOP value of group 1 was 14.55 +/- 2.95 mmHg and 13.92 +/- 2.58 mmHg in group 2. We detected no statistically significant difference between group 1 and group 2 (P = 0.053). The mean IOP values for group 3 and group 4 were 16.26 +/- 2.33 mmHg and 15.19 +/- 2.40 mmHg, respectively. We detected a statistically significant difference between groups 3 and 4 (P = 0.005). Group 5's mean IOP value was 12.97 +/- 2.65 mmHg. IOP values measured with DCT were statistically significantly higher compared with IOP values measured with NCT and GAT (P < 0.0001 and P < 0.0001, respectively). Additionally, IOP values measured with NCT were statistically significantly higher compared with IOP values measured with GAT (P < 0.0001). Conclusion According to the results of our study, silicone hydrogel soft contact lens use does not significantly affect IOP values measured with NCT, but it affects IOP values measured with DCT. Eye (2012) 26, 278-282; doi:10.1038/eye.2011.271; published online 11 November 2011