Provocation of the ocular surface to investigate the evaporative pathophysiology of dry eye disease

Paramdeep Bilkhu*, James S. Wolffsohn, Christine Purslow

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Purpose: To investigate whether standard clinical measures of tear film stability, meniscus height and symptomology reflect changes in evaporation rate induced by ocular surface provocations. Methods: Forty participants (23.8 ± 4.5 years, 53 % female) with healthy to mild dry eyes underwent two tear film provocations in random sequence on separate occasions: playing a tablet computer high concentration game ( for 30 min; and receiving treatment with humidity goggles for 10 min followed by liposomal spray application. Measures at baseline and 30 min later were: Symptom Assessment iN Dry Eye (SANDE) questionnaire, tear film lipid layer thickness (LLT), non-invasive tear film break-up time (NIBUT), tear meniscus height (TMH), dynamic tear film lipid layer pattern (DLP) and tear film evaporation (TFE). Results: There were no differences in the baseline measurements before each provocation (p > 0.05). Dry eye symptoms significantly worsened with concentration task (p < 0.001) and improved with treatment (p < 0.001). DLP and LLT significantly increased with treatment (p < 0.05), but was unaffected with the concentration task (p > 0.05). NIBUT declined with the concentration task (p = 0.015), but was not enhanced with treatment (p = 0.142). TMH increased after treatment (p = 0.001) and decreased with the concentration task (p = 0.006). While evaporation decreased with the concentration task (p < 0.001), treatment had no effect (p = 0.333). LLT was associated with evaporation (p = 0.036) and additionally with symptom severity (p = 0.002) and tear volume (p = 0.017). Conclusions: Sub-classifying dry eye based on an ‘evaporative’ component to inform treatment seems over-simplistic. However objective TMH, NIBUT and LLT seem to be the key clinical metrics that drive ocular comfort.

Original languageEnglish
Pages (from-to)24-29
Number of pages6
JournalContact Lens and Anterior Eye
Issue number1
Early online date20 Apr 2020
Publication statusPublished - Feb 2021


  • Dry eye
  • Evaporation
  • Tear film


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