Abstract
Purpose: :
To evaluate intraocular pressure (IOP) parameters and corneal biomechanical properties as measured by the Ocular Response Analyzer (ORA; Reichert Ophthalmic Instruments, Buffalo, NY) in Chinese subjects with primary angle closure glaucoma (PACG) and primary open angle glaucoma (POAG).
Methods: :
Consecutive subjects from a glaucoma clinic diagnosed to have PACG and POAG were enrolled in this cross-sectional observational study. Normal controls were enrolled from an ongoing population-based study. One eye of each subject underwent comprehensive ocular examination and ORA measurements. The ORA parameters of corneal hysteresis (CH) and corneal compensated IOP (IOPcc) were documented in each subgroup for a comparative analysis.
Results: :
Of the 333 subjects recruited, 69 had PACG, 162 had POAG, and there were 102 normal subjects. Bland-Altman showed that mean values of IOPcc were higher than GAT IOP values in eyes with PACG [2.1 mm Hg (95% Confidence Intervals (CI): -5.6 to 9.8 mm Hg; p<0.001] and POAG [1.0 mm Hg, 95%CI: -5.3 to 7.4 mm Hg; p<0.001]. This difference was not noted in normal eyes [- 0.1 mm Hg, 95%CI: -6.3 to 6.1 mm Hg, p=0.84]. Mean CH was lower in eyes with PACG (9.0 ± 1.7 mm Hg) and POAG (9.5 ± 1.4mm Hg) in comparison to normals (10.5 ± 1.5mm Hg; p<0.05).
Conclusions: :
IOPcc values in Chinese subjects with PACG were consistently higher than GAT values in comparison to POAG and normals. PACG and POAG eyes have lower CH than normals. These data may add further insights into corneal biomechanical properties in glaucomatous eyes.
Keywords: intraocular pressure • clinical (human) or epidemiologic studies: systems/equipment/techniques • protective mechanisms