A Study of the Tono-pen for Assessing Ocular Pressure in Patients with Headache Combined with Ocular Pain in the Emergency Department

ABSTRACT

PURPOSE: To study the use of the Tono-pen to estimate intraocular pressure (IOP) in patients with a headache combined with ocular pain in the emergency department (ED). METHODS: We carried out a prospective, single-centre study comparing the Tono-pen to the Goldmann tonometer in 31 patients. The two methods were compared according to measured IOP and diagnosis, and the results were analyzed for correlations. RESULTS: 31 patients (17 male, 14 female, mean age 51 years) were enrolled. The mean IOP according to the Tonopen and Goldmann were 19 mm Hg (95% CI: 14-25) and 18 mm Hg (95% CI: 12-23), respectively. The mean difference in measurement between the two was 1.8 mmHg. The 95% limits of agreement were -4.5 to 8.1 mmHg, and the correlation coefficient r was 0.976. In those patients with IOP > or = 25 mmHg, four (40%) were diagnosed of glaucoma. CONCLUSION: The Tono-pen was a very useful screening tool for patients presenting with headache combined with ocular pain in the ED.