Fatty layer of the precorneal film in the 'office eye syndrome'.

The thickness of the fatty layer of the precorneal film was estimated by the semiquantitative inteference method in 70 office workers from two town halls in Copenhagen County and compared with that in 110 controls from the general population. There were significant correlations between use of eye make-up and a thin fatty layer (less than or equal to 50 nm, P = 0.023) and between investigation time before 12 h and a thick fatty layer (greater than or equal to 150 nm, P = 0.046). After correction for these confounders, the fatty layer was significantly reduced in the office population compared with the controls (P = 0.0032). Furthermore, absence of biomicroscopically dry eyes (expressed as a combination of premature break-up of the tear film and lissamine green-stained epithelial damage of the bulbar conjunctiva) was significantly correlated to a thick fatty layer (greater than or equal to 150 nm, P = 0.015), indicating that a thick fatty layer may protect the eyes against development of dry eyes. The results indicate that deficiency in available Meibomina oil is involved in the dry eye syndrome we earlier found to be associated with eye irritation in the office environment and termed the 'office eye syndrome'. Together with observation of foam in the eye canthus, estimation of break-up time, and examination for clusters of epithelial damage on the bulbar conjunctiva, measurement of the fatty layer appears to be an easy tool for diagnosing the 'office eye syndrome' or for differentiating this disorder from other conditions with complaints of dryness or irritation.