Prospective Comparative Analysis of 4 Different Intraocular Pressure Measurement Techniques and Their Effects on Pressure Readings

Thomas A. Berk, Patrick T. Yang, Clara C. Chan
2017 Journal of glaucoma  
Purpose: To compare intraocular pressure (IOP) measurement using the Goldmann applanation tonometry (GAT) without fluorescein, with fluorescein strips, with fluorescein droplets, and IOP measurement with Tono-Pen Avia (TPA). FIGURE 1. Bland-Altman plot of Goldmann applanation tonometry (GAT) with anesthetic only versus GAT with fluorescein strip showing a mean difference of À 2.05 mm Hg with 95% limits of agreement between À 5.89 and 1.79 mm Hg. The data points with superscript numbers
more » ... >1 patient, and their superscripts indicate the number of patients they represent. Figure 1 can be viewed in color online at between GAT with and without fluorescein, finding that not using fluorescein underestimated readings by 5.62 mm Hg on average. Bright et al 10 similarly found that lack of fluorescein underestimated IOP by an average of 7.01 mm Hg, and also identified a trend of increasing discrepancy between the 2 techniques as IOP values increase. Fluorescein droplet was applied in their study. They postulated that both of these phenomena relate to an erroneous FIGURE 2. Bland-Altman plot of Goldmann applanation tonometry (GAT) with anesthetic only versus GAT with fluorescein droplet showing a mean difference of À 3.13 mm Hg with 95% limits of agreement between À 8.09 and 1.84 mm Hg. The data points with superscript numbers represent >1 patient, and their superscripts indicate the number of patients they represent. Figure 2 can be viewed in color online at http://www.glaucomajournal.com FIGURE 3. Bland-Altman plot of Goldmann applanation tonometry (GAT) with anesthetic only versus Tono-Pen Avia (TPA) showing a mean difference of À 3.68 mm Hg with 95% limits of agreement between À9.27 and 1.92 mm Hg. The data points with superscript numbers represent >1 patient, and their superscripts indicate the number of patients they represent. Figure 3 can be viewed in color online at http://www.glaucomajournal.com Berk et al J Glaucoma Volume 00, Number 00, " 2016 4 | www.glaucomajournal.com perception of the applanated area on the part of the ophthalmologist when fluorescein is not used. When properly calibrated, a GAT accurately measures IOP when the circular applanated surface has a diameter of precisely 3.06 mm. Because of surface tension attraction between the GAT probe tip and the corneal surface, a 360-degree wedge of tears is adjacent to the circumferential border of the applanation area. The GAT is designed so that the FIGURE 4. Bland-Altman plot of Goldmann applanation tonometry (GAT) with fluorescein strip versus GAT with fluorescein droplet showing a mean difference of À 1.08 mm Hg with 95% limits of agreement between À 4.02 and 1.87 mm Hg. The data points with superscript numbers represent >1 patient, and their superscripts indicate the number of patients they represent. Figure 4 can be viewed in color online at http://www.glaucomajournal.com FIGURE 5. Bland-Altman plot of Goldmann applanation tonometry (GAT) with fluorescein strip versus Tono-Pen Avia (TPA) showing a mean difference of À 1.63 mm Hg with 95% limits of agreement between À7.54 and 4.29 mm Hg. The data points with superscript numbers represent >1 patient, and their superscripts indicate the number of patients they represent. Figure 5 can be viewed in color online at
doi:10.1097/ijg.0000000000000651 pmid:28221334 fatcat:jwxb5rwegvcgrcx4e6a66ixbda