Abstract
Abstract: :
Purpose: Aim of the work was the measurement of the temperature profile of the anterior ocular surface of the human eye in normal subjects . In patients without significant tear film abnormalities , this parameter is related to ocular hemodynamics and its evaluation could provide clinically useful informations about ocular blood flow by means of an easy performed and low invasive technology. Methods: Forty patients ( 22 women and 18 men ) free of ocular diseases , tear film abnormalities and refractive errors higher than 3 dpts were included in the study.The ocular surface temperature values were measured by an infrared detector AGEMA 880 and processed by a specific software . For every patient the measurement was performed twice , the first time at baseline ( frame 1 ) and the second one after ten seconds with the eye completely open and avoiding blinking ( frame 2 ). The data of five locations simmetrically distributed along an horizontal line passing through the center of the cornea were particularly considered .The changes of the temperature data between frame 1 and 2 , and the differences for age and sex were analyzed by means of the Student t-test while the differences among the five different locations were studied by means of ANOVA . The results were considered statistically significant if p<0.05. Results: 1) The comparison between the data of the frame 1 and frame 2 showed a significant temperature decrease , more evident in the central corneal location , probably due to progressive tears evaporation. 2) The temperature distribution is not homogeneus in the five considered locations along the horizontal line and it is lower in the central cornea and higher in the lateral extremities ( especially on the nasal side ) , probably because cornea avascularity. 3)The temperature profile of patients aging over 50y is significantly lower in comparison with those under 50y , in agreement with previous papers reporting an impairment of ocular hemodynamics in aged subjects 4) The temperature decrease with increasing age can be equally appreciated in males and females , even if it is more evident for the frame 2 in women . Conclusion: The infrared system AGEMA 880 coupled with a specific software was able to detect significant thermographic differences between different experimental situations , topographic locations and demographic groups , in normal subjects . This technology might provide more interesting informations in pathologic conditions affecting ocular hemodynamics ( diabetes , glaucoma , ocular vascular diseases ).
Keywords: 331 blood supply • 599 topography • 309 aging