DETERMINATION of intraocular pressure is now recognized as an essential part of routine ophthalmologic examination, especially with subjects over 40 years of age. The tonometer might thus be used in testing patients with acute conjunctivitis, dacryocystitis, syphilis, gonorrhea, or tuberculosis, and care must be taken, of course, that the instrument does not become a carrier of infection. It is necessary, therefore, to keep the tonometer at all times in an aseptic condition, and a simple, reliable method of sterilization assumes practical importance.
Mere wiping with alcohol1 will not suffice, as alcohol has only an antiseptic, not a bactericidal, effect. Immersion in alcohol is not a safe measure either; in addition, it tends to gum up the plunger. Ether, which has been suggested as a substitute,2 is not more efficient than alcohol. The germicidal properties of benzalkonium (Zephiran) chloride are limited, and when the substance is used in sufficiently
TOWER P. A SIMPLE METHOD FOR STERILIZING THE TONOMETER. AMA Arch Ophthalmol. 1953;50(4):512-513. doi:10.1001/archopht.1953.00920030520014