[Measure of the fatty layer thickness of precorneal tear film by interference colours in different types of dry eye].

PURPOSE: Measure the thickness of lacrimal fatty layer in several pathologies with ocular dryness, by the study of interferencial colours.

METHODS

A prospective study of 100 patients (50 males and 50 females), divided in ten groups was performed. The first nine groups had dry eye pathology, the other one was the control group of healthy patients. We measured with the slit lamp the fatty layer thickness by the study of interferencial colours.

RESULTS

We found a greater thickness of the fatty layer in patients with pathologies like seborrheic blepharitis, keratoconjunctivitis sicca, chronic blepharitis and contact lens wear, compared with the control group. Patients with climatic and ambiental dry eye had a thin fatty layer compared with the control group. We didn't find statisticaly significative differences between control group and the patients with chronic conjunctivitis or atopic conjunctivitis.

CONCLUSIONS

The thickness of the fatty layer changes in different dry eye pathologies. Interferencial colours study is a semiquantitative and non invasive method to measure the thickness of fatty layer of precorneal tear film. It s easy to perform and interprete, so we must include this as a part of the dry eye diagnostic study.