Shimon Kurtz1, Uri Soiberman1, Gabi Shemesh1. 1. Department of Ophthalmology Tel Aviv Medical Center, Israel, and the Sackler Faculty of Medicine, Tel Aviv University, Israel.
Abstract
BACKGROUND: Normal tension glaucoma (NTG) is a chronic progressive optic neuropathy, characterized by relatively normal intraocular pressure (IOP) measurements. This study utilized three modalities in the measurement of lOP: dynamic contour tonometry (Pascal-DCT), Goldmann applanation tonometry (GAT) and Tonopen XL. OBJECTIVES: To compare the lOP measurements of the three devices in eyes with NTG. METHODS: This retrospective study of thirty-three NTG patients (66 eyes) who underwent lOP measurements using the three devices was approved by a local ethics committee. The lOP measurements were stratified according to central corneal thickness (CCT) and corneal curvature (CC). RESULTS: The mean DCT IOP was higher (16.22 +/- 3.04 mmHg) than the mean GAT IOP (13.14 +/- 2.83 mmHg, P < 0.0042). The mean Tonopen XL lOP was lower than the mean GAT IOP (12.76 +/- 3.11 mmHg, P < 0.001). GAT and DCT measurements were significantly infLuenced by corneal curvature (P = 0.004 and P < 0.0001, respectiveLy). CONCLUSIONS: lOPs measured by GAT or Tonopen XL were consistently lower than by DCT. CC significantly influenced GAT and DCT results.
BACKGROUND:Normal tension glaucoma (NTG) is a chronic progressive optic neuropathy, characterized by relatively normal intraocular pressure (IOP) measurements. This study utilized three modalities in the measurement of lOP: dynamic contour tonometry (Pascal-DCT), Goldmann applanation tonometry (GAT) and Tonopen XL. OBJECTIVES: To compare the lOP measurements of the three devices in eyes with NTG. METHODS: This retrospective study of thirty-three NTG patients (66 eyes) who underwent lOP measurements using the three devices was approved by a local ethics committee. The lOP measurements were stratified according to central corneal thickness (CCT) and corneal curvature (CC). RESULTS: The mean DCT IOP was higher (16.22 +/- 3.04 mmHg) than the mean GAT IOP (13.14 +/- 2.83 mmHg, P < 0.0042). The mean Tonopen XL lOP was lower than the mean GAT IOP (12.76 +/- 3.11 mmHg, P < 0.001). GAT and DCT measurements were significantly infLuenced by corneal curvature (P = 0.004 and P < 0.0001, respectiveLy). CONCLUSIONS: lOPs measured by GAT or Tonopen XL were consistently lower than by DCT. CC significantly influenced GAT and DCT results.