A survey of intraocular silicone oil use in the United States

Comparison of intraocular pressure using Goldmann applanation tonometry versus non-contact tonometry in eyes with high-viscosity silicone oil

BACKGROUND

To compare intraocular pressure (IOP) measurements using Goldmann applanation tonometer (GAT) and air tonometer (non-contact tonometry [NT]) in vitrectomized eyes with high-viscosity silicone oil tamponade, as well as in normal eyes.

PATIENTS AND METHODS

In this prospective comparative study, 32 eyes with silicone oil tamponade of high viscosity (5700 CS) and 32 normal fellow eyes were included. IOP was measured by GAT and air tonometer 30 ± 12 days after vitrectomy, while measurements of central corneal thickness (CCT) were also obtained.

RESULTS

In eyes with silicone oil, IOP was 20.09 ± 4.91 mmHg and 16.75 ± 3.86 mmHg using contact tonometer and air tonometer, respectively (p < 0.0001). In normal eyes, IOP was 16.41 ± 2.15 mmHg and 16.31 ± 2.49 mmHg using the same tonometry techniques and this difference was not statistically significant (p = 0.598). In addition, no significant correlation was detected between IOP measurements using both techniques and age, gender, CCT, and type of lens.

CONCLUSIONS

It seems that GAT overestimates IOP in eyes with high-viscosity silicone oil compared with NT, while both IOP measurement techniques in normal eyes provide similar values. Further assessment of available IOP measurement methods could possibly establish the most accurate technique for IOP estimation in vitrectomized eyes with silicone oil tamponade.

IOP measurement in silicone oil tamponade eyes by Corvis ST tonometer, Goldmann applanation tonometry and non-contact tonometry

PURPOSE

To compare the postoperative intraocular pressure (IOP) of eyes following pars plana vitrectomy (PPV) combined with intravitreal silicone oil (SO) tamponade by Corneal Visualization Scheimpflug Technology (CST), Goldmann applanation tonometry (GAT) and non-contact tonometry (NCT).

METHODS

Thirty-eight participants who had undergone PPV combined with SO tamponade to treat vitreoretinal diseases were enrolled. Postoperative IOP measurements were obtained using CST, NCT and GAT. Inter-device agreement was assessed by Bland-Altman analysis. The correlation coefficient was used to describe the potential postoperative factors affecting the postoperative IOP differences between each device.

RESULTS

Bland-Altman analysis revealed the bias between CST and GAT, between CST and NCT, and between GAT and NCT to be -0.2, 2.1 and 2.4 mmHg, respectively. CST and GAT correlated well with each other. NCT values were lower than those of GAT and CST (all p < 0.05), whereas CST values did not differ from the GAT readings. Central corneal thickness, corneal biomechanical properties and age showed significant correlation with the differences of CST-NCT and GAT-NCT.

CONCLUSIONS

In SO tamponade eyes, NCT obtains lower IOP than other tonometry techniques, and CST is highly consistent with GAT. CST offers an optional non-contact method for measuring postoperative IOP in SO tamponade eyes.