Posters

Evaluation of the ocular surface cooling rate in patients suffering with dry eye syndrome

Poster Details

First Author: S.Matteoli ITALY

Co Author(s):    E. Favuzza   S. Cappelli   A. Corvi   P. Aragona   R. Mencucci  

Abstract Details

Purpose:

The objectives of this work were 1) to develop a procedure based on Infrared thermography for the cooling characterization of ocular thermal behavior in patients suffering from dry eye, 2) to be able to differentiate among patients suffering from aqueous tear-deficiency (ATD) and evaporative dry eyes (EDE).

Setting:

Eye Clinic, University of Florence, Florence, Italy, and Department of Industrial Engineering, University of Florence, Italy.

Methods:

Thirty-five patients (30F/5M, 23-80 years old) were enrolled. Exclusion criteria were: glaucomatous optic neuropathy, retinal and choroidal diseases, corneal abnormalities, diabetes mellitus and a body temperature higher than 37.5 °C. The two eyes of each patient were studied by dividing them only according to their degree of Schirmer I (≤ 10 mm for ATD and >10 mm for EDE) without putting distinctions between left and right eye. The thermocamera FLIR A320 was used for recording the temperature of both eyes of all patients for 7s at a frequency of 30Hz. For each acquisition the temperatures of the center of the cornea and of both temporal and nasal canti were evaluated with an image processing technique.

Results:

The thermal analysis showed proportionality between the degree of Schirmer I and temperature variation in the three selected areas. Patients suffering from EDE showed an initial Ocular Surface Temperature (OST) higher than those with ATD, which may be explained by the greater quantity of the tear film that distributes itself evenly over the whole ocular surface, and initially keeps higher the OST. Specifically, the temperature variation was 0.6°C for EDE and 0.2°C for ATD patients. By normalizing data it was also possible to calculate the cooling rate for both groups: 0.09%/s for ATD patients and 0.26 %/s. The ocular surface cooling rate was 65% greater for patients suffering from EDE than those suffering from ATD.

Conclusions:

Ocular thermography appears to be an effective and reliable tool for differentiating between the two forms of the disease, avoiding the discomfort to patients due to the traditional tests, and the influence of possible reflex tearing on the measurements. FINANCIAL INTEREST: NONE