RT Journal A1 Hughes WF T1 BEta radiation sources, uses, and dangers in treatment of the eye JF Journal of the American Medical Association JO Journal of the American Medical Association YR 1959 FD August 22 VO 170 IS 17 SP 2096 OP 2101 DO 10.1001/jama.1959.63010170013013 UL http://dx.doi.org/10.1001/jama.1959.63010170013013 AB Beta radiation from radium, radon, and radium D-E has been used in the treatment of certain external ocular conditions for about 40 years because of the relatively superficial effects and accurate localization of the radiation. More recently, radioactive strontium (Sr90)-yttrium (Y90) applicators have become available as a source of beta particles or electrons for ocular use. The early enthusiastic reports of the efficacy of beta radiation have been tempered by the appearance of certain secondary complications including cataract. Therefore, it becomes more important that the clinician be aware of the sources, rationale, uses, contraindications, dosages, and dangers of beta therapy.Characteristics of Various Sources of Beta Radiation  Various sources and applicators have differing characteristics in surface output, depth dose, and amount of gamma rays. A comparison of available data1 on these applicators is given in table 1. The differences in the construction of the applicators, their