ABSTRACT
PURPOSE: To evaluate the diagnostic validity of the HNT-1P non-contact tonometer (Huvitz) as a tool for accurately measuring intraocular pressure (IOP) in patients with healthy eyes, compared to the Goldmann applanation tonometer (GAT), which is the Gold Standard method for measurement of IOP. METHODS: Observational, descriptive, transversal study using 148 eyes of 74 healthy patients without a diagnosis of glaucoma or other ophthalmological diseases. Three measurements of IOP were taken in each eye, using three tonometers: HNT-1P, ICR100, and GAT. The median IOP (quartiles) and mean IOP (SD) its statistical significance were calculated, and comparisons were made between the mean and median IOP values found in three groups: GAT-HNT, GAT-ICR, and HNT-ICR. The difference in mean and median IOP was analyzed in each of the three study groups, and its statistical significance and concordance correlation coefficient (CCC) were calculated. RESULTS: The median IOP with HNT-1P was statistically significantly lower than the median IOP with GAT, (1.1â mmHg, p < 0.001). The median IOP with HNT-1P was also lower than the median IOP with ICR100. As an additional result, the median IOP with GAT was lower than the median IOP with ICR. The CCC was moderate for HNT-ICR (0.72) and low for GAT-HNT and GAT-ICR (0.43 and 0.38, respectively). CONCLUSIONS: HNT-1P (Huvitz) provides statistically significantly lower IOP values than those obtained with GAT. HNT-1P could be used for screening of ocular hypertension in postoperative patients. The IOP measurement obtained with HNT-1P should be confirmed with GAT. HNT-1P yields lower IOP values than those obtained with ICR.
ABSTRACT
PURPOSE: The purpose of this study was to evaluate the intraobserver repeatability of several corneal parameters in healthy eyes using a new swept-source optical coherence topographer. METHODS: Fifty right eyes of 50 subjects were enrolled in this study. A single examiner performed 3 consecutive measurements using the Anterion swept-source optical coherence tomography. The following corneal parameters were evaluated: average keratometry (K), steep K, flat K, astigmatism, best fit sphere, and maximum keratometry on the anterior and posterior surfaces at 3 mm, average K, steep K, flat K, and astigmatism in the total corneal power map at 3 mm, central corneal thickness and thinnest point thickness in the pachymetric map, and corneal diameter. To assess the repeatability of the measurements, we calculated the following indexes: intrasubject SD (Sw), coefficient of variation, coefficient of repeatability, and intraclass correlation coefficient (ICC). RESULTS: High repeatability was reported for all the evaluated corneal parameters, with Sw values lower than 0.027, coefficient of variation values lower than 0.066%, and coefficient of repeatability values lower than 0.187. ICC values showed a high correlation between measurements in all cases, being the lowest value for the astigmatism of the anterior surface (ICC = 0.92); for the rest, ICC values were larger than 0.98. Finally, we have not found statistically significant differences between repeated measurements (P > 0.05). CONCLUSIONS: The anterior segment measurements provided by the Anterion swept-source optical coherence tomography device show high intraobserver repeatability in healthy eyes.