Comparison of intraocular pressures after myopic laser-assisted subepithelial keratectomy: Tonometry-pachymetry, Goldmann applanation tonometry, dynamic contour tonometry, and noncontact tonometry

Abstract

To compare intraocular pressure (IOP) measurements using a new tonometer-pachymeter device (Tonopachy), Goldmann applanation tonometry (GAT), dynamic contour tonometry (DCT), and noncontact tonometry (NCT) before and after myopic laser-assisted subepithelial keratectomy (LASEK). Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea. Prospective comparative observational study. Nine IOP values were measured using 4 tonometers (6 IOPs by tonometer-pachymeter and 1 each by GAT, DCT, and NCT) and compared preoperatively and 3 months postoperatively. Of the 6 IOP values measured by the tonometer-pachymeter, 1 showed uncorrected IOP and 5 indicated central corneal thickness (CCT)-corrected IOPs through different formulas. Preoperatively and postoperatively, the means of 9 IOP values measured by 4 tonometers were statistically different. The IOP measurements by the tonometer-pachymeter correlated with all other IOP values preoperatively; however, there was no correlation with IOP measurements using DCT postoperatively. Some IOPs using the tonometer-pachymeter were interchangeable with those using GAT preoperatively, but not with DCT preoperatively or postoperatively. The corrected IOP values of the tonometer-pachymeter formula 3 and DCT did not change after surgery. The percentage change in CCT and corneal curvature and change in diopters correlated with the percentage change in IOP measurements by GAT and NCT but not with those using DCT and the tonometer-pachymeter. Among the 9 IOP values, corrected IOP using the tonometer-pachymeter formula 3 showed similar IOP values after LASEK, as did DCT. No author has a financial or proprietary interest in any material or method mentioned.