Reliability of applanation tonometry readings obtained with a disposable latex cap.
To verify the accuracy of applanation tonometry through disposable latex caps used to prevent transmission of infectious diseases. Tonometry was performed in 80 patients. Each patient underwent two intraocular pressure (IOP) measurements with and without the latex. In group A patients tonometry was performed first without the cap; in group B tonometry was performed first with the cap. Each group was also divided into patients with IOP, >/=20 mm Hg (A1; B1) and patients with IOP <20 mm Hg (A2; B2). The mean difference of tonometry readings was equal to -0.36 +/- 1. 62 mm Hg in group A, -0.03 +/- 1.77 mm Hg in group A1, -0.61 +/- 1. 45 mm Hg in group A2, 0.23 +/- 1.44 in group B, 0.64 +/- 1.41 mm Hg in group B1, 0.05 +/- 1.42 in group B2. A statistically significant correlation was found in group A, in group A2, B, B1 and B2; a less significant correlation was found in group A1. The use of the latex caps does not alter the reliability of tonometry readings as long as the cap is applied tightly. Measurement variation in our study is comparable to published data on applanation tonometry.