The optimum temperature for the heat therapy for meibomian gland dysfunction.

PURPOSE: Numerous devices have been developed to warm the eyelid as a therapy for Meibomian gland dysfunction. The optimum temperature for such therapy was determined.

METHODS: Meibum lipid disorder versus temperature was calculated from previously published phase transition parameters measured using infrared spectroscopy. Phase transitions parameters were calculated from meibum obtained from donors with Meibomian gland dysfunction (MMGD ), donors who were susceptible to dry eye after hematopoietic stem cell transplantations (MHSCT ) and meibum from donors without dry eye (Mn).

RESULTS: Heating Mn to 40 °C increases the lipid disorder by 20.4%-90%. Heating the meibum another 4° increases the disorder to 95%. MMGD is 73.2% disordered with no heating. Heating MMGD to 41.5 °C increases the disorder by 26.8%-90% disordered. Heating MMGD another 5.1 °C increases the disorder to 95%. As MHSCT is much more ordered, 56.9% disordered compared with Mn and MMGD , a higher temperature above safety limits, 52 and 59 °C is need to disorder MHSCT to 90 and 95% disorder.

CONCLUSIONS: Heating the eye lid above the phase transition temperature of meibum increases the disorder of meibum lipid which could ameliorate dry eye symptoms. The optimum temperature for disordering Mn and MMGD to 90% maximum disorder is 40 and 41.5 °C, respectively. Safety issues and discomfort should be considered in obtaining an optimal level of disorder, especially for severe cases of dry eye.