This study was motivated by the lack of data on pediatric ophthalmological trauma in the southwest of China. The study aimed to obtain and summarize the etiological and clinical characteristics of severe ocular injuries from the children admitted to the West China Hospital.
Etiological and epidemiological profile
The frequency of pediatric traumatic cataract treated in the hospital followed a decreasing trend, which was not obvious. Hence, the pediatric traumatic cataract remained a major source of blindness. A sudden drop in the frequency in 2015 might be partly because a sudden ban on fireworks was enforced. In all age groups, the traumatic cataract occurred predominantly in boys, which was consistent with previous findings in Shanghai [7], but had some differences compared with the results in China Taiwan [17] and Lithuania [18], which showed that the risk of eye injury was significantly higher in girls than in boys in the younger age group (≤1 year old and <7 years old, respectively). These findings could be explained by the more aggressive and violent nature of activities in which boys were involved compared with girls. Also, the ratio of boys to girls increased after the age of 8 years. The reason was that the psychological maturity in boys lagged behind that in girls, and hence the boys were less aware of self-protection. In the present study, the risk of eye injury was the highest in the age group of 5 years, which was consistent with previous findings [9, 19]. Children aged 4–6 years had a higher risk of getting traumatic cataract. This was possibly because children of this age could walk independently, and their guardians were not always close by, resulting in insufficient supervision. In addition, children of this age were very curious and eager to explore their external environment, yet with limited awareness of danger. Despite the inadequate ability to self-protect, children eventually learn the concept of danger through daily observation. Thus, the occurrence of ocular injuries appears to decline with age, as shown by the data. The marked decrease in the frequency of traumatic cataract observed in children older than 6 years might be attributed to schooling and homework. A regular presence at school could reduce their time participating in dangerous activities.
The causes of ocular injuries were diverse and tended to vary among different countries due to different socioeconomic backgrounds and living environments. The main causes of pediatric traumatic cataract in the present study were sharp metal objects, followed by botanic sticks and stationery. The result of this study was different from the findings of Yu Du [7] on the pediatric traumatic cataract in Shanghai, which showed toys as the second main cause. In Changsha, one of the main causes were fire crackers [9]. In India, the main causes were wooden splinter, bow, and arrow [20, 21]. And in Egypt, the main causes was wooden sticks[10]. In the present study, toy and firecracker accounted for a smaller percentage.
The main causative agent seems to vary according to the physical development of children. For boys and girls aged less than 6 years, sharp metal objects were the major cause, followed by botanic sticks. It was concluded that boys and girls were engaged in almost similar daily activities before the age of 6 years [22], which also explained the relatively lower ratio of boys to girls in the frequency of traumatic cataract in younger ages. The decreasing contribution of sharp metal objects but the increasing contribution of stationery might result from universalized compulsive education and increasing attention on sharp metal objects. The higher the level of education, the less the risk of getting an ocular injury. A previous study confirmed that more ocular injuries occurred at rural places because of low-level education [9].
In 2020, an outbreak of a new coronavirus infection occurred in China. The children had more time spending at home with their parents, but the frequency of pediatric traumatic cataract increased instead of being decreased. The phenomenon could be explained by the fact that the pediatric traumatic cataract occurred most frequently at home, which was confirmed by other studies. The home was the most common place where pediatric ocular injuries happened, followed by outdoor and school [23, 24]. In addition, the most common causes in the present study were scissors and knives usually found in every household, which also confirmed that home was the main site of occurrence of ocular traumas. Therefore, it was necessary to emphasize the importance of preventive measures in the home environment.
The results of the present study also pointed to a seasonal difference among the injuries. A majority of the injuries occurred in winter (40.2%). Other studies conducted in different areas reported that injuries most commonly occurred during the summer months in Wenzhou of China[9], and Canada[25], and the autumn months in southwestern Turkey [22]. Of course, these seasonal differences might result from the climatic characteristics and the lifestyle of people in the region where the study was conducted. In Sichuan, China, where the present study was performed, the second longest vacation was in winter; children generally spent a lot of time playing, while parents usually were busy in preparing for the Spring Festival. In addition, fire crackers were set off as a traditional custom. These conditions above accounted for the higher frequency of ocular trauma in winter. The reason for comparatively fewer injuries in the spring and autumn seasons was that the children were in school and busy with homework. Summer, being the hottest, limited the activity of the children.
In this study, the penetrating injury was the most common type of open-globe injury in children, followed by blunt rupture, which was similar to the results reported by others in Chinese cities such as Shanghai [7], Wenzhou, and Changsha [9], and other countries as Iran [26], the US [11], and Tunisia [27]. However, the result perhaps was contrary if all kinds of ocular injuries were included; the main cause was a blunt strike to the eye [18, 28, 29]. Rupture had a significantly more possibility in vitreous hemorrhage, and retinal detachment compared with penetration. Retinal detachment was associated with a poor visual outcome. Therefore, for children with blunt trauma or rupture, it was necessary to examine the fundus so as to treat the retinal disease earlier.
Endophthalmitis profile
This study found that needle, wooden stick, and bamboo skewer injuries have more possibility for post-traumatic endophthalmitis. The reasons for a needle injury developing into endophthalmitis were as follows: greater contamination and deeper penetration into the eye; and repair or delayed therapy because of the ignorance of parents or doctors. As shown in the present study, most patients hurt by a syringe needle and developing into endophthalmitis approached the hospital more than 24 h after getting injuries. Wooden sticks, as organic matter, had a greater risk of getting contaminated [30]. Thus, injuries caused by wooden sticks had a greater possibility for developing into endophthalmitis. As for bamboo skewers, deeper penetration, ignorance, and easy contamination could explain the result.
The most commonly isolated organism related to post-traumatic endophthalmitis in the present study was Streptococcus, which was consistent with the Alfaro’ [31] and Al-Rashaed’ [32] findings, but different from the Yan Sheng systematic review study on Chinese pediatric post-traumatic endophthalmitis, which showed that the most common organism was Staphylococcus epidermidis [33]. In the present study, a more virulent species, E. cloacae [34], was involved. The isolated organism was reported to be a commensal organism of the gastrointestinal tract instead of the ocular surface [35], and was found in soil and plants. Hence, it was clear that E. cloacae was identified in post-traumatic endophthalmitis caused by wooden sticks. The patients and doctors should pay more attention to injuries caused by wooden sticks.
Measures for prevention
As for the prophylaxis for pediatric trauma, we should emphasize educative and legislative measures such as informing parents, teachers, and children about the causative factors and potential hazards of ocular injuries and restricting the availability of dangerous items to children. Some suggestions are as follows: (1) Younger children should be kept away from sharp metal objects or be paid attention to when they use sharp metal objects. Tips of scissors should be made blunt at the time of manufacturing. (2) Since the home was the main place where pediatric ocular trauma happened, children should be provided a safe home surrounding. (3) Children should be helped to develop an earlier sense of safety. (4) Children should wear protective spectacles when playing with toys, such as marble and slingshot. (5) Laws should be implemented for manufacturers to inform consumers of potential dangers and minimize the inherent risks associated with particular products by including child-resistant packaging, printed warnings, and age recommendations. (6) The sale of fire crackers to underage children should be forbidden; also, they should not set off crackers without permission. (7) Boys and children aged 4–6 years had a higher risk of traumatic cataract, and hence need more attention.
This study had several limitations. First, it had some inherent biases because of its retrospective design. Second, the data were limited to what was provided in the patients' medical records. Third, the study probably slightly underreported the actual incidence rate of pediatric traumatic cataract in the Sichuan province because only injuries treated at the West China Hospital were included. So multicenter research is expected. Finally, only injuries associated with the open-globe traumatic cataract were included in this study. Close-globe injuries and those not involving the traumatic cataract were excluded. Therefore, the epidemiological characteristics shown in this study could not represent characteristics of other kinds of ocular trauma. Therefore, more comprehensive research is needed.