Clinical evaluation of the pressure phosphene tonometer in patients with glaucoma.

AIM To evaluate the reliability of the pressure phosphene tonometer in comparison with the Goldmann applanation tonometer. METHODS 45 consecutive patients with glaucoma (78 eyes) participated in the study. Eyes with previous eye surgery, a documented peripheral visual field defect, a refractive error of more than 5 dioptres, and patients who were unable to understand the procedure were excluded from the study. Intraocular pressure was measured with a pressure phosphene tonometer by one examiner and with a Goldmann applanation tonometer by two other examiners no more than 15 minutes apart. A second series of measurements was performed several weeks later on 34 patients (59 eyes). There was no communication between examiners or between examiner and patient regarding test results. RESULTS No statistically significant correlation was found between the applanation tonometry values and those obtained with a pressure phosphene tonometer. CONCLUSION The pressure phosphene tonometer is not suitable for reliably measuring intraocular pressure.