LAUSR

40 mm) may result in both positive and negative effects on acupoints. Wellorganized controlled studies would thus be necessary to address the proposed mechanism of IPL action and most of the questions posed by Zhu and Jin. As we describe in our study, we defined refractory meibomian gland dysfunction (MGD) as MGD that failed to show any improvement in response to at least 3 types of conventional therapy over a period of at least 1 year. Our clinical impression is that such patients show low expression of meibum. It is difficult to define a “good effect” for these patients, but our results demonstrate a greater improvement in subjective clinical symptoms after IPL and meibomian gland expression in those with a long duration of MGD and those who underwent more treatment sessions. The extent of clinical improvement did not seem to be related to the number of meibomian gland dropouts, and we did not evaluate its relation to meibum quality or eradication of Demodex. The optimal exposure procedure for IPL has not been established, although it is not sufficient simply to warm the eyelid. Current IPL machines allow irradiation over a broad band of wavelengths that seem to deliver heat energy in an effective manner to the skin.