Abstract
Purpose :
Intraocular pressure (IOP) is an important glaucoma risk factor. Studies have shown that engaging in physical exercise may protect against the damage caused by elevated IOP. In our study in a glaucoma cohort, we aimed (1) to evaluate short-term exercise-induced changes in IOP and ocular vascular parameters and (2) to assess electroretinogram (ERG) PhNR changes after exercise and changes in intraocular pressure (IOP).
Methods :
Participants 40-80 years with glaucoma (mean deviation between -2 and -20 dB in at least one eye) completed 2 study visits: (1) off glaucoma drugs (off-treatment) for 3 days, (2) on glaucoma drugs (on-treatment), after treatment resumption for at least 1 week. At each visit, subjects exercised on an exercise bike for 10’ with concurrent heart rate monitoring. Paired t-tests evaluated pre- vs. post-exercise, and on-treatment vs. off-treatment, differences in IOP, optic nerve head (ONH) blood flow parameters measured (heart-rate adjusted peak, dip and mean blood flow from laser speckle imaging), and hand-held RetEval ERG was used for measuring the photopic negative response (PhNR).
Results :
14 eyes of 7 participants (mean age=67±6 years) were analyzed. IOP decreased with exercise for both the off-treatment (mean IOP of 22.7±5.4mmHg dropping to 17 ±4.8mmHg, p<0.0001) and on-treatment (mean IOP of 17.7±4.3 mmHg dropping to 14.1 ±3.4mmHg, p<0.0001) conditions. In the off-treatment condition, several ONH blood flow parameters (heart rate adjusted peak, dip, and mean blood flow) decreased post-exercise with (p<0.001 for all). PhNR (Implicit time in ms) post-exercise showed delayed response with a mean implicit time of 88.59± 22.38 ms (pre-exercise) to 98.66 ± 28.58 ms (post-exercise), with a mean difference of 10.08± 13.40, p=0.01. Exercise in the on-treatment condition showed less dramatic changes in ONH blood flow parameters (peak: p=0.07, dip: p=0.02; mean blood flow: p=0.03). On-treatment PhNR implicit time changed post-exercise from 101.1± 28.72 ms (pre-exercise) to 89.97 ± 23.29 ms (post-exercise).
Conclusions :
Short-term exercise was noted to lower IOP and alter several ONH blood flow parameters. Further studies are needed to investigate if exercise can translate into long-term changes in ONH blood flow.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.