The Case-crossover Study of Work-related Eye Injuries in Taiwan

Work-related eye injuries are important etiologies of blindness, and account for a large proportion of occupational injuries. Work-related eye injuries not only hurt workers themselves and their family, but also cause huge loss of productive power and social cost. The purpose of this study was to describe the epidemiology of work-related eye injuries in Taiwan. We also conducted the case-crossover study with telephone-interviewed structured questionnaires to explore the transient preventable and risk factors of work-related eye injuries. A total of 283 cases reported from eight ophthalmologic teaching hospitals in Taiwan ranging from 2003 to 2006 were completely interviewed. The results showed that most of those injured were male (91.5%) and the average age was 40.2 years. 47.7% whose education was below junior high school and 81.6% of cases had an annual income less than NT$ 500,000. The most liable to suffer injury was workers engaged in traditional industries (34.6%), construction (24.7%), and agriculture (15.2%). Among these cases, 66.7% were from small enterprises with workers number below 10 or self-employed workers, and 85.9% were menial workers. 76.3% of those injured are senior workers who had worked more than 5 years. Most common mechanisms of work-related eye injuries were welding (30.4%), drilling/cutting (13.4%), chemicals splash (11.7%), and hammering (10.2%); and injuries were frequently caused by welder’s flash /radiation (33.2%), projectile/blasting fragments (20.9%), sharp objects (15.2%), and chemical solvents (12.4%). 68.6% of subjects were closed eye globe injuries, among which radiation (33.2%) and chemical burn (14.1%) were most common injured types. 31.4% were open eye globe injuries. 55.2% of patients had a visual acuity of 3/60 or less at the time of the injury; it was suggested that 64.3% of patients have OPD follow-up after primary treatment.
In case-crossover study, matched-pair interval study was first used and the results showed that wearing eye protective devices (EPD) could reduce 64% relative risk of work-related eye injuries (OR=0.36, 95% CI=0.17-0.74). On the other hand, the relative risk of work-related eye injuries increased when performing unfamiliar tasks (OR=57.0, 95% CI=14.1-230.7), operating unusual tools or equipments (OR=24.0, 95% CI=3.2-177.4), distracted (OR=24.0, 95% CI=3.2-177.4), rushing (OR=13.0, 95% CI=3.1-54.8), fatigued (OR=10.0, 95% CI=1.3-78.1), or working under special environments (OR=4.3, 95% CI=1.4-12.6). However, there was no significantly protective effect of wearing EPD while analyzed with usual frequency approach ( IRRM-H=1.21, 95% CI=0.79-1.86). The data was further stratified with occupational categories, job experiences, and hazard materials; and it was found that EPD did have protective effect to agriculture workers (IRRM-H=0.06, 95% CI=0.01-0.96), junior workers (IRRM-H=0.19, 95% CI=0.13-0.28), and workers threatened by projectile objects (IRRM-H=0.34, 95% CI=0.14-0.83). The results of this study indicated the protective effect of EPD was limited; worker’s attitude and practice, and working environments were more determining risk factors to work-related eye injuries. Accordingly, strategies including designing appropriate health education and safety training programs, strengthening safety culture, providing proper protective devices, and engineering control must to be introduced to both high-risk workers and administrators to reduce the incidence of work-related eye injuries in Taiwan.