Effect of Valsalva Manoeuvre on Short Term Variation of Intra Ocular Pressure

Abstract

BACKGROUND: Intra ocular Pressure (IOP) changes during Valsalva manoeuver (VM). AIM: To study the effect of Valsalva manoeuvre on IOP and the heart rate response. MATERIALS AND METHODS: The study group consisted of 55 volunteers, visually normal as subjects, 30 boys and 25 girls in the age group of 18 to 20 years. Independent measurements of the IOP of each eye were obtained with the subject in the upright position. ECG recorded continuously before, during and after the Valsalva manoeuvre. Keelar Pulsair air impulse tonometer was used in all the subjects for IOP measurement. IOP was measured in the department of Ophthalmology, Teaching Hospital between 08AM to 10 AM. STATISTICAL ANALYSIS: were done using Paired 't' test. RESULTS: The mean IOP increased by 5.53±2.138 mmHg during VM. The changes were statistically significant (<0.001). Mean IOP decreased by 2.085±0.367 mmHg during VM in a small proportion of subjects (12%) which was not statistically significant. Mean recovery IOP was also lower than the resting IOP which was statistically significant (<0.001). The Valsalva ratio is calculated as the ratio of the longest RR interval (ms) after the maneuver divided by the shortest RR interval (ms) during the test. Mean Valsalva ratio was normal at 1.687 (range 1.2-2.6). CONCLUSION: IOP increased during Valsalva manoeuvre in a large number of subjects (88%). Recovery IOP was also lower than the resting IOP during the period of measurement, post VM (over a period of 5 minutes).