Comparison of Biomechanically Corrected Intraocular Pressure Obtained by Corvis ST and Goldmann Applanation Tonometry in Patients With Open-angle Glaucoma and Ocular Hypertension.

PRECIS

Biomechanically corrected intraocular pressure (bIOP) measurements provided by the new Corvis ST (CST) were higher than measurements obtained with Goldman applanation tonometry (GAT) in eyes with ocular hypertension (OHT) or open-angle glaucoma (OAG).

PURPOSE

To compare bIOP obtained with a new version of CST with GAT measurements in patients with OAG and OHT, and to identify factors affecting IOP measurement differences between these methods.

METHODS

A total of 122 eyes with OAG or OHT were enrolled. Sixty eyes were treated with prostaglandin analogs (PGA) and 62 eyes with selective laser trabeculoplasty (SLT). IOP was measured with CST, followed by GAT. Central corneal thickness (CCT) was measured with ultrasound pachymetry. Measurements obtained with these 2 approaches were compared.

RESULTS

The overall mean IOP was 15.2±3.0 mm Hg and 14.1±3.2 mm Hg with the CST and GAT, respectively (r=0.74; P<0.0001). There was a 1.17 mm Hg bias between tonometers, with 95% limits of agreement of -2.66 to 5.01 mm Hg. According to multivariate regression analysis, differences between bIOP and GAT-IOP were associated with CCT (P=0.001) and age (P=0.007) in the PGA group, but only with CCT in the SLT group (P=0.002). bIOP and GAT-IOP values were influenced by age (PGA: P=0.014; SLT: P=0.006) and CCT (PGA: P=0.007; SLT: P=0.032), respectively.

CONCLUSIONS

BIOP values were higher and less affected by CCT than GAT-IOP values in eyes with OAG and OHT. However, these measurements may not be interchangeable in the clinic.