Intraocular pressure responses during maximal and submaximal handgrip strength tasks in primary open-angle glaucoma patients and healthy individuals

Background This study aimed to compare intraocular pressure (IOP) responses during isometric handgrip strength tasks between primary open-angle glaucoma patients and healthy individuals. Methods Forty older adults participated: 21 glaucoma patients and 19 controls. Participants randomly performed four trials at two intensities, maximal and submaximal (at 50% of self-perceived maximal effort), with two trials per hand (one for the left eye and one for the right eye). IOP was measured immediately before exercise, during exercise, and 5 seconds post-recovery. A four-factor mixed ANOVA was used to analyze IOP responses, with task intensity and time of measurement as within-subject factors, and group (glaucoma vs. control) and sex as the between-subjects factors. Results IOP responses were comparable between glaucoma patients and healthy individuals, as the main effect of group ( p = 0.117) and its interactions did not reach statistical significance. The main effect of time reached statistical significance ( p = 0.016) due to greater IOP values during the task (17.3 ± 3.7 mmHg) compared to pre-exercise (16.3 ± 3.2 mmHg: p < 0.001), but post-exercise IOP (16.9 ± 4.1 mmHg) was not significantly different from pre-exercise ( p = 0.334) or during exercise ( p = 0.727). Greater IOP values were observed for the maximal task compared to the submaximal task ( p = 0.001), with no differences between men and women ( p = 0.699). Conclusion Submaximal isometric strength training is a safe option for glaucoma patients treated with hypotensive eye drops.