Articles about Eye Health and Disease from 2005


Exposure to Cosmic Radiation May Increase the Risk of Cataracts in Airline Pilots


(From Vilhjalmur Rafnsson, MD, PhD, et al., Arch Ophthalmol. 2005;123:1102-1105)


Due to the nature of their profession, airline pilots may have an increased exposure to ionizing radiation of cosmic origin.  Also, this type of radiation has been associated with the development of cataracts.  In this population-based case-control study, the investigators set out to determine if there was an increased risk of cataract, by type, in commercial airline pilots related to their exposure to cosmic radiation.

In this study of 445 male airline pilots, lens opacification (cataract) was classified into 4 types using the World Health Organization grading system. These 4 types, serving as cases, included 71 men with nuclear cataracts, 102 with cortical lens opacification, 69 with central optical zone involvement, and 32 with posterior subcapsular lens opacification. Control subjects were those with a different type of lens opacification or without lens opacification. Exposure was assessed based on employment time as pilots, annual number of hours flown on each aircraft type, time tables, flight profiles, and individual cumulative radiation doses (in millisieverts) calculated by a software program. Odds ratios were calculated using logistic regression.

The risk of the nuclear type of cataract in the pilots was compared to the control group and to non-pilots, and was adjusted for age, smoking status, and sunbathing habits.  The risk of nuclear cataract in pilots was found to be 3.02 times greater in airline pilots than in non-pilots (odds ration of 3.02).  The odds ratio for nuclear cataract associated with estimation of cumulative radiation dose (in millisieverts) to the age of 40 years was 1.06, adjusted for age, smoking status, and sunbathing habits.

The authors of the study concluded that the association between the cosmic radiation exposure of pilots and the risk of nuclear cataracts, adjusted for age, smoking status, and sunbathing habits, indicated that cosmic radiation may be a causative factor in nuclear cataracts among commercial airline pilots.




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