In this study, our purpose was to obtain and summarize the demographics, etiologies and clinical characteristics of pediatric ocular trauma in Southwest of China over an 11-year period to provide evidence-based information for protection awareness education and further medical management. Children less than 12 years of age with PPV were included. The ratio of male to female was 4.3:1 (99 males and 23 females) in this study, higher than the sex ratio of 1.18:1 derived from the latest available census data in China [13]. Moreover, many studies reported a higher incidence of trauma in males than in females [7, 9, 13-16], showing an average male-to-female ratio which ranged between 1.2:1 and 5.2:1. In our study, the male to female ratio was increased as patients grew, which was consistent with a study conducted by Yu Du et al. [13] in Shanghai, China. They found the peak of sex ratio was at 12:1 around 10 – 12 years old. Other studies showed similar results as well [2, 7, 14, 17]. We also found that the incidence of ocular trauma decreased in both males and females as they grew up, especially in females. This could be explained by the fact that children receive primary health education and self-protection when they get older. Males are more likely to participate in dangerous and risky activities [18, 19], which might result in higher rate of ocular trauma in males compared to females.
With regards to the time distribution of ocular trauma in our study, there were over 20% of cases occurred in February, which was usually the season of Chinese New Year. Many children like playing firecrackers during this period. It might largely increase the risk of eye injury. In our study, firecrackers were the third major cause of ocular trauma, which was similar as the study of Xu et al [16]. However, Ilhan et al. observed that most frequently occurred in the autumn [7] and Podbielski et al. found that globe injuries most occurred in the summer [20]. These seasonal differences may be related with the climate characteristics and lifestyle of different areas [7].
Our finding was consistent with previous reports [13, 15, 16, 21, 22] on children ocular trauma that penetrating injury caused by sharp objects had absolute predominance. Other causes include wooden stick, firecrackers, recreational activities and accidental domestic injuries. But Puodžiuvienė et al [14] suggested that the most common type of ocular trauma was closed globe injury. Literatures showed that 90% of all ocular trauma was avoidable [23]. Figuring out the major cause of injury, it will help parents and doctors establish effective protection to reduce the incidence of ocular trauma in children.
PPV has been used to manage lens and posterior segment trauma when surgery is needed [24]. Previous studies mentioned the advances of PPV in treating severely damaged eyes and improved visual outcomes [9, 25]. In young children, it is very challenging to perform vitreoretinal surgery due to the complex features of the vitreous, retina, and the interface between them [26]. In this study, 74 eyes underwent 2 times or more surgeries, which suggested that those cases may arise serious complications, such as postoperative hypotony, retinal detachment, proliferative vitreoretinopathy and bacterial endophthalmitis [27, 28]. Anatomical successful rate in our study was 79%, and it was associated with intraocular tamponade. Silicone oil was used most in our study, and its outcome was worst compared to the other two tamponades, which might be related with severity of eye injury. Advantages of silicone oil include the high interfacial tension and a refractive index close to that of vitreous, so it becomes an attractive alternative for clinic application [9, 29].
In our study, 28% of patients achieved VA of 4/200 or better, and 20% achieved 20/200 or better after vitrectomy. Compared to previous studies [9, 26], the VA improvement in our study was not so well as the outcomes of all kinds of vitrectomy in pediatric patients [9, 26]. The possibility might include the preoperative degree of injury, severer underlying pathology or more extensive postoperative inflammation, hypotony [29], scarring and proliferative vitreoretinopathy [30]. Obviously, PPV improved both the anatomical and visual outcomes in the pediatric patients despite potential problems with proliferative vitreoretinopathy and deprivation amblyopia.
Initial VA was a strong prognostic indicator of final VA evaluation [7, 31, 32]. Nevertheless, causative factors related to the beneath retinal pathology seem to influence postoperative functional outcomes. Previous studies [6, 14, 17] suggested the final VA was associated to the injury type for open globe injury carried a poorer prognosis. But in our study, no statistically significant difference was found between the final VA and either age or classification of injury, which was consistent with the finding by Feng et al [7].