Momentary Fluctuations of Intraocular Pressure in Normal and Glaucomatous Eyes

To examine the range of momentary fluctuations of intraocular pressure caused by vascular pulsations in 42 glaucomatous and 18 normal eyes, we obtained consecutive intraocular pressure measurements at hourly intervals with a noncontact air tonometer. Glaucomatous eyes had a significantly (P < .001) greater range of intraocular pressure measurements on consecutive readings than normal eyes (4.4 ± 1.4 mm Hg vs 2.7 ± 0.7 mm Hg). The frequency of consecutive intraocular pressure readings exceeding a spread of 4 mm Hg was significantly increased in glaucomatous eyes. The range of intraocular pressure measurements was greater even in those glaucomatous eyes with mean intraocular pressures within the normal range. There was a positive correlation between mean intraocular pressure and mean range in glaucomatous eyes, but not in normal eyes. In both glaucomatous and normal eyes, there was no significant correlation between age and mean range.