Experimental Assessment of the Spatial and Temporal Distribution of Non-contact Tonometer Airflows

Abstract

Aim of the study was to investigate the spatial and temporal characteristics of the airflow created by two commercially available non-contact tonometers, the CorvisST and the Ocular Response Analyser. (2) The airflow pressure was measured using a MEMS pressure sensor to investigate the spatial and temporal distribution. The airflow from the CorvisST and Ocular Response Analyser was mapped to a 600 microns and a 1mm resolution grid, respectively. (3) Central airflow pressure of the CorvisST (96.4 &amp;plusmn; 1.4)mmHg was higher than the Ocular Response Analyser (91.7 &amp;plusmn; 0.7)mmHg. The duration of the air-puffs also differed, with the CorvisST showing a shorter duration (21.483 &amp;plusmn; 0.2881)ms than the ORA (23.061 &amp;plusmn; 0.1872)ms. The rising edge of the CorvisST airflow pressure profile demonstrated a lower gradient (+8.94mmHg/ms) compared to the Oc-ular Response Analyser (+11.00mmHg/ms). Both had similar decay response edges; CorvisST -11.18mmHg/ms, Ocular Response Analyser -11.65mmHg/ms. (4) The study presents a valid method to investigate physical dimensions of the airflow pressure of non-contact tonometers. Novel findings relating to the magnitude, duration and spatial characteristics of the respective airflow pressures are reported. It is anticipated that this information will better inform clinical studies and theoretical models relating to ocular biomechanics.</jats:p>