A cryoprobe working on the Joule Thomson principle using the expansion of carbon-dioxide gas is described. It is the first cryoprobe that can be applied to the lens at ambient temperature (room temperature) having almost instantaneous freezing and rewarming characteristics. Iris adhesion and laceration are virtually impossible. Automatic foot switch control as well as reserve freezing power, for difficult cases, are incorporated. The probe is light, small, and well-balanced and the tip is constantly visible. There is no gaseous carbon-dioxide discharge near the operative site. The probe has facilitated the technique of cryoextraction using a superior polar grip and iris retraction as first described by the author. The instrument is especially valuable in the extraction of dislocated, subluxated, and complicated cataracts.
Amoils SP. The Joule Thomson Cryoprobe. Arch Ophthalmol. 1967;78(2):201-207. doi:10.1001/archopht.1967.00980030203014