Systems and methods improve operation of an applicator that delivers heat-generating energy to an eye as a part of an eye therapy. For example, reflected power may be measured to determine whether sufficient contact has been established between the applicator and the eye for accurate and precise delivery of energy to the eye. In addition, at least one of forward and reflected power may be measured to monitor the application of coolant pulses that control the generation of heat in the eye when the applicator delivers energy to the eye. Further, the forward and reflected power may be measured to determine an efficiency of energy transfer or an impedance mismatch. Based on the efficiency of energy transfer or the impedance mismatch, an adjustable parameter of a tuning element may be modified.