This study found that automobiles were the main vehicle and being a teenager was the risky group for the occurrence of road traffic-related OGI in Northern Thailand. Penetration by pieces of glass and being hit by part of vehicle were the most frequent associated causative mechanisms. The presence of RAPD and retinal detachment were found to be significant predictors at the initial examination for poor final visual outcome.
The impact of road traffic accidents has been evaluated in several hospitalized eye trauma studies. In Taiwan, Lee et al. demonstrated that the main cause for both principal (20.4%) and secondary diagnosis (47.2%) of admitted eye trauma was traffic accident . In China, Qi et al. pointed out that almost a quarter of hospitalized eye injury (24.2%) occurred from vehicle-related accidents . Nevertheless, when considering the overall incidence of road traffic-related OGI which attained a poorer visual prognosis compared to closed globe injury, the variation in incidence according to countries has been published . In high-income countries, a low incidence of road traffic accidents has been shown which included a study by Li et al. (2%) from Hong Kong, Beshay et al. (2%) from Australia, Fujikawa et al. (3.4%) from Japan, Court et al. (3.4%) from New Zealand, and Orr et al. (4%) from US [3, 14, 15, 20, 21]. In contrary, a much higher incidence has been reported in a study by Madhusudhan et al. (17.6%) from Malaysia and, accordingly, in this study (9.4%) which were both characterized as middle-income countries . With a relatively high incidence of road traffic-related eye injuries in this region, it is essential to have more actions from the government and community to make the road safer. However, to establish effective enforcement of a road safety system, it is reasonable to properly define the vulnerable risk groups and investigate related consequences following eye injury.
Considering about gender, the result of this study is consistent with other OGI publications, either investigated for overall causes or only for traffic-related injury, which found that male was a major proportion of patients than female, even though varying in ratio [13, 15, 16, 20, 22]. This may refer to differences in physical activities between genders. Therefore, public awareness for road safety legislation should be promoted to better understanding among the population, particularly males. Apart from gender, specific age range has been observed to differ between causes of OGI. In fall down-related OGI, the peak incidence has been described in young children and elderly, while patients between 30 to 40 years were at increased risk for occupational-related OGI [3, 4, 16, 23]. Nevertheless, in road traffic-related OGI, the disparities in age range have been demonstrated. A study in US by Orr et al. presented that nearly half of cases (48%) were young patients between 20 to 40 years whereas a study in Japan by Okamoto et al. found that road traffic injury comprised a more proportion of elderly patients with a mean age of 50 years [20, 22]. This study, similar to Zhang et al., demonstrated that the highest incidence occurred in young patients between 20 to 39 years which represented teenagers and/or early working groups . This finding is in line with a previous report in Thailand which showed that the most commonly admitted road traffic injured age group was 15 to 30 years old . The less experienced in vehicle-related performance and an easily distracted nature might possibly explain the high incidence of injury in this age range. Then, strategies to encourage the use of safety equipment and follow the safety instructions involving vehicle transportation should be emphasized.
Types of vehicle is another factor that should be accounted for. A study by Orr et al. reported that nearly all cases (96%) were injured by automobiles and the minority were (4%) injured by motorcycles . Okamoto et al noted that the two most frequent injuries were related to car driving (36%) and bicycle riding (14%), while the minority were related to motorcycle riding (7%) . However, this study revealed that the proportion of transportation modes varied by age range. Motorcycles were the most prevalent in the young while the automobiles were the most frequent in adult and elderly. Regular inspection of safety behaviors during riding/driving including seat belt using, helmet wearing, speed limitation, and non-alcohol or non-mobile phone might benefit for injury prevention across all age groups.
About the mechanism of injury, there were pieces of evidence that globe rupture was the most prevalent type (60 to 64%) in road traffic-related OGI [20, 22]. This study noted that a similar proportion of patients sustained injuries from globe rupture and penetration (47 versus 45%). This may refer to the nature of road traffic accidents with a higher chance to obtain diffuse ocular damages by both blunt forces, including hit by vehicle parts or road–related construction, and sharp penetration by objects such as glass. On the contrary, most work-related OGI studies have shown that penetration was the most common mechanism [4, 23]. The high proportion of ruptures may partly explain a low visual potential. In this study, even though VA was significantly improved when comparing final to initial visits, 46% of the patients achieved final vision worse than 20/200. Consequently, aiming for prevention combined with prompt treatment should be an effective way to reduce severe visual impairment from road traffic-relate OGI.
This study had some limitations due to its retrospective design. As such, detailed information regarding patient and injury severity may under or overestimated. Furthermore, as this is a hospital-based study, it might not represent the minor injured population. However, the results point out several aspects of road traffic OGI characteristics in a middle-income country that should be of concern.