RESUMO
PURPOSE: To assess the effect of vectored thermal pulsation treatment for meibomian gland dysfunction on objective measures of lipid layer thickness (LLT) and tear osmolarity. METHODS: One hundred patients with meibomian gland dysfunction diagnosis were recruited to participate. At their initial visit, baseline study parameters were recorded, and vectored thermal pulsation treatment was administered. At the 2- to 3-month follow-up visit, the study parameters were reevaluated. Subjective symptoms were evaluated using the Ocular Surface Disease Index questionnaire. LLT was measured using an ocular surface interferometer. Tear osmolarity was calculated using impedance measurement of tear fluid collected from the eyelid margin. RESULTS: Ninety-six patients (192 eyes) completed the follow-up. Mean improvement in Ocular Surface Disease Index was 5.6 points (95% confidence interval [CI], -9.0 to -2.1, P = 0.002). There was no significant change in tear osmolarity (mean change -1.6 mOsm/L, 95% CI, -4.7 to +1.3 mOsm/L, P = 0.3). There was no significant change in LLT (mean change -4.3 nm, 95% CI, -9.1 to +0.5 nm, P = 0.08). CONCLUSIONS: The hypothesis that vectored thermal pulsation treatment would decrease tear osmolarity and increase LLT was not substantiated. Although we detected significant improvement in subjective symptoms, the improvement was smaller than the improvements reported in previous studies. Our results suggest that the current understanding of the effects of vectored thermal pulsation treatment is incomplete.