A system for applying therapy to an eye selectively applies coolant to the corneal surface to minimize heat-related damage to the corneal surface during thermokeratoplasty. Embodiments may include an energy source, a conducting element, a coolant supply, and a coolant delivery system. The conducting element is operably connected to the energy source and extends from a proximal end to a distal end. The conducting element directs energy from the energy source to the distal end, which is positionable at the eye. The coolant delivery system is in communication with the coolant supply and is operable to deliver a micro-controlled pulse of coolant to the distal end.