Ex vivo heat retention of different eyelid warming masks

Meibomian gland dysfunction (MGD) appears to be the most common cause of evaporative dry eye, in which the meibum has an altered chemical structure that increases its melting point. Eyelid warming masks slowly transfer heat, preferably between 40 and 45°C to the inner meibomian glands, in an attempt to melt or soften the stagnant meibum. This ex vivo study evaluates the heat retention properties of commercially available masks over a 12-min interval.

Five eyelid-warming masks (MGDRx EyeBag®, EyeDoctor®, Bruder®, Tranquileyes™, Thera°Pearl(®) were heated following manufacturer's instructions and heat retention was assessed at 1-min interval for 12 min on a non-conductive surface. A facecloth warmed with hot tap water was used as comparison.

All masks reached above 40°C within the first 2 min after heating and remained so for 5 min, with the exception of the facecloth, which lasted only 3 min and quickly degraded to 30°C within 10 min. The Bruder® and Tranquileyes™ reached >50°C, after heating and the Bruder® maintained >50°C for nearly 6 min. The MGDRx EyeBag®, and Thera°Pearl® had the most stable heat retention between 2 and 9 min, remaining between the targeted temperature.

Heat retention profiles are different for commercially available eyelid warming masks. This ex vivo study highlights that despite the popularity of the time-honored facecloth, it is poor at retaining the desired heat over a 5-10 min interval. Clinical studies need to corroborate these results, remembering that ocular tissue parameters may be factors to consider.