Ocular Surface Temperature: Characterization in a Large Cohort of Healthy Human Eyes and Correlations to Systemic Cardiovascular Risk Factors

Abstract

Purpose: To characterize ocular surface temperature (OST) in healthy eyes and its association with systemic risk factors of cardiovascular and ischemic heart disease. Methods: This prospective cross-sectional study included consenting subjects who were examined at the Institute for Medical Screening in Sheba Medical Center. A Therm-App™ thermal imaging camera (Opgal LTD, Israel) was used for OST acquisition, and the mean OST of the medial canthal, lateral canthal, and central cornea regions were measured. Room and body temperatures were also recorded. Past medical and ocular history as well as data from various clinical examinations performed at the same visit were obtained. Results: Thermographic images were obtained from 186 subjects, 150 of which were included in the final analysis. OST was significantly higher in the medial canthal, central cornea, and lateral canthal regions in people with a history of ischemic heart disease (p = 0.02, p = 0.02, and p = 0.03, respectively). There were no significant OST differences (ANOVA test) associated with the presence of hypertension, diabetes mellitus, or active smoking status. Conclusions: OST correlated positively with the presence of ischemic heart disease. This correlation, its pathophysiological base, and its clinical application warrants further investigation.

The cold‐sensing ion channel TRPM8 regulates central and peripheral clockwork and the circadian oscillations of body temperature

“…To study a possible role of TRPM8 in eye blood flow, we determined eye temperature (Teye) by infrared (IR) thermography in WT and Trpm8 −/− mice exposed to different temperatures. Previous studies have shown that ocular haemodynamics can be estimated indirectly by measuring ocular surface temperature 31,32 . Mice were placed on a steel platform and exposed to a cold ramp.…”

“…Previous studies have shown that ocular haemodynamics can be estimated indirectly by measuring ocular surface temperature. 31,32 Mice were placed on a steel platform and exposed to a cold ramp. The plate temperature (Tplate) was decreased linearly from 30 to 0°C (1°C/min).…”

The Effect of Face Masks during COVID-19 Pandemic on Ocular Surface Temperature—A Clinical Thermographic Analysis

“…Statistical significance was set at p < 0.05. Minimum sample size for 80% power and 0.05 alpha, was estimated as 27 eyes/subjects using a single-sided sample size calculator for comparing two paired means [ 27 ] based on an expected mean of the paired differences of 0.5 and expected 1.0 standard deviation of the paired differences based on previous studies [ 14 , 15 , 16 ]. Assuming a 10–15% dropout rate, the total number of participants needed was estimated to be 31 subjects.…”

“…In a recent large prospective cross-sectional study, Cohen et al, used the Therm-App thermal imaging camera (Opgal Ltd., Karmiel, Israel) to measure OST among individuals undergoing annual general screening tests. In this cohort, they observed a significantly higher OST among persons diagnosed with ischemic heart disease, although no significant association was noted for persons with hypertension, diabetes mellitus or active smoking [ 14 ]. The use of OST as a possible biomarker for retinal disease and glaucoma has also been reported recently [ 15 , 16 ].…”

Use of Infrared Thermography in Medical Diagnosis, Screening, and Disease Monitoring: A Scoping Review

“…Autism, 2021 [17], Diabetes type II, 2020 [33,34] FLIR Systems, Wilsonsville, OR, USA, ThermoVision A20 160 × 120, 0.12 • C at 30 [45] Ischaemic heart disease, 2021 [54] OptoTherm, Sewickley, PA, USA Thermoscreen 640 × 480, <0.04 • C ±1 • C Fever, 2010 [37], 2011 [38],…”