Effect of isometric handgrip exercise on intraocular pressure among healthy adult males

Glaucoma is the main cause for irreversible blindness in India. The main determinant of glaucoma is raised intraocular pressure (IOP) which is influenced by many factors. One of the main factors is physical exercise. Objective of this study is to exhibit the effect of isometric handgrip exercise using Smedley's handgrip dynamometer on IOP among young adult males in the south Indian population. In this quasi experimental study, 150 young healthy adult male subjects with ages between 15 to 40 years were selected on the basis of fulfilling our inclusion and exclusion criteria with the help of a questionnaire. Baseline IOP and maximum voluntary contraction (MVC) of the subjects were measured using non-contact tonometer and Smedley's Handgrip Dynamometer, respectively. The subjects were instructed to hold the handgrip dynamometer with 20% of MVC in sustained manner for minimum 2 min or until fatigue sets in. IOP were measured on both eyes immediately and 15 min following exercise and IOP variation was analysed using paired t-test. A small but significant decrease in IOP was noted immediately as well as 15 min following exercise. Average fall in right eye was 1.75 mm Hg immediately and 2.14 mm Hg 15 min following exercise (P<0.01). The average fall in the left eye was 1.62 mm Hg immediately and 1.91 mm Hg after 15 min (P<0.01). Isometric handgrip exercise of the single upper limb showed significant reduction of IOP on both eyes following exercise and the decrease was much higher 15 min after exercise. This result can be extrapolated and clinically applied for glaucoma prevention and supplemented as lifestyle modification during glaucoma treatment.