Closed Chamber Thermometry and Humidity Measurements in Normal and Dry Eye Patients: A Pilot Study

Purpose To verify the diagnostic value of closed chamber thermometry and humidity measurement in normal and dry eye patients. Methods In 20 patients (40 eyes) with dry eye and 20 normal sex- and age-matched controls (40 eyes), aged from 11 to 61 years (mean 37.52 yrs, standard deviation, (SD) 14.81) temperature was measured by infrared thermometry and humidity measured in a closed chamber 15 mm from the cornea. The temperature reading in °C and humidity in % (RH) were noted on closing and then opening the eye for five seconds. Results The temperature rose significantly, by 0.11°C ± 0.02, between the closed and open eye positions (p<0.000) in normal eyes, but there was no change in dry eyes. The humidity in normal eyes in the closed position was 49.50 ± 4.67% and 50.03 ± 4.65% in the open position (p<0.00001). Humidity in the closed and open positions in dry eyes was 52.77 ± 7.13% and 53.59 ± 6.75% (p<0.00000). The difference between closed and open dry eyes was 1.25 ± 0.40%, compared to 0.54 ± 0.20% in normal controls (p<0.005). No relationship was found with age or sex. Conclusions Thermometry and humidity measurements in a dry eye patient had a 100% diagnostic value. The reading of no change in thermometry and more than 1% change in humidity were highly diagnostic of dry eyes.