Qom University of Medical Sciences Journal

Background and Objectives: Glaucoma is one of the leading causes of blindness, and its major risk factor is elevated intraocular pressure. Intraocular pressure measurement is a major examination in patients with glaucoma for diagnosis and treatment follow-up. This study was carried out with the purpose of comparing the accuracy of two types of conventional tonometers for measuring intraocular pressure.   Methods: In this descriptive cross-sectional study, after complete ophthalmologic examinations, intraocular pressure was measured in 142 patients (284 eyes), two times at 5-minute intervals using both Goldmann and Keeler tonometers. The obtained results were analyzed with paired t-test and Pearson’s correlation test.   Results: Mean intraocular pressure in subjects that were in normal pressure range (<21mmHg) was obtained 14.03±2.35mmHg with Goldmann tonometer, and 14.28±3.05mmHg with Keeler tonometer. The mean difference of the two methods was 0.25±0.70 (p=0.015) and the correlation coefficient between two methods was calculated 0.83 (p<0.0001). Mean intraocular pressure in high intraocular pressure range (³21mmHg) was obtained 26.16±5.1mmHg with Goldmann tonometer, and 26.92±5.58mmHg with Keeler tonometer. The mean difference of the two methods was 0.76±0.44 (p=0.003), and correlation coefficient between two methods was calculated 0.97 (p<0.0001).   Conclusion: Based on the results of this study, both used tonometry methods had acceptable accuracy in normal intraocular pressure range, but in high-risk cases such as glaucoma, Goldmann applanation tonometer is preferred as the gold standard.