Comparison of Evaporimetry With the Established Methods of Tear Film Measurement

Purpose:

The purpose of this study was to establish whether there is a correlation between dry eye symptoms, age and gender, any difference in symptom intensity in different times of the day, which test (Schirmer or TBUT) better correlates with dry eye symptoms, whether it is possible to reliably use cheap, easy to use hygrometer in everyday clinical setting, and, finally, whether there is statistically significant correlation between applied tests (TBUT, Schirmer and evaporimetry).

Methods:

Subjects were divided in two groups: 45 in group without dry eye related symptoms, and 45 in group with symptoms.

Examination was performed in the following sequence:

• structured case history (questionnaire),
• evaporimetry
• slit lamp examination with fluorescein staining,
• TBUT test and
• Schirmer test I (without anesthetic, closed eyes)

Case history consisted of the following questions:irritation more pronounced on wind? irritation during reading and/or watching TV or computer? irritation more pronounced during winter? gritty sensation in the eyes? irritation more pronounced in the morning or evening? All answers, except to the last question, were graded from 0 (no complaints) to 3 (severe).

Evaporimetry was performed using commercially available hygrometer from HYGROTEC (Titisee-Neustadt, Germany), installed in swimming goggles with its front part sawn off.

First measurement was performed by measuring for 5 minutes with eyes closed. Second measurement also lasted 5 minutes, with eyes kept open, normal blinking, and with subject fixating at one point in distance, with no eye movements.

Measured parameters included:

basal φ (%): relative environment humidity before measurement basal T: environment temperature before measurement closed eye φ (%): relative humidity in front of closed eye open eye φ (%): relative humidity in front of open eye C/O: ratio of φ (%) closed/open eye

Inclusion criteria

• patients with or without dry eye symptoms

Exclusion criteria

• minors
• pregnant women
• patients with acute eye conditions (inflammation, allergy, trauma)
• patients with chronic eye diseases requiring continuous topical treatment (i.e.glaucoma)
• ocular surface scarring
• patients who did not sign informed consent.