Gender and age are two mutually correlated major risk factors for ocular trauma
Totally, 206 patients were reviewed at Shanghai General Hospital between January 2016 and December 2018. 96.12% of the patients were admitted to hospital and took the surgical treatment within the first 24 hours of trauma. Interestingly, majority of the patients were males (88.35%) (Table 1). In the occupation category, we found that most of the male patients are workers; however, none of ocular trauma patients in this group is female (Table 1, Fig.1A & B). By analyzing the type of ocular traumas, we further found that gender significantly affects the trauma incidence. Male patients account for the majority of the ocular trauma incidence caused by penetrating injury (33.5% with IOFBs, and 34.95% without IOFBs). In contrast, only small portion of the female patients had such type of injury (Table 1).
Next, we found that the gender difference in ocular trauma incidence is closely associated with age (Table 1, Fig. 1A). The mean age of the patients was 49.32 ± 19.00 years old (y/o). Not surprisingly, majority of patients (46.12%) fell into 40~60 y/o age group. However, among 40~60 y/o group, male patients account for 44.2%, whereas female patients only account for 1.9% of total patients (table 1). The gender difference also appeared in other age groups except for the child group, which only includes three cases (Table 1, Fig.1A). Thus, we identified gender and age as two mutually correlated major risk factors for ocular trauma.
Occupation and penetrating injury
Of 206 patients, 58.74% of ocular trauma patients in our study cohort were workers engaged in the field of manual, industrial and decoration settings (Table 1). However, eye injuries were rarely seen in those people whose occupation does not require intensive manual labor, such as students, teachers, and retirees, etc., underscoring occupation as a remarkable risk factor for ocular trauma, although it does not apply to farmers who may rarely expose their eyes to the risk environment in this study (Table 1).
Since occupation is closely linked to ocular trauma incidence, we then analyzed types of injuries that may contribute to occupation related ocular trauma. We found that more than half of patients who are workers had penetrating injuries (77 of 121 worker patients, Table 1), suggesting that penetrating injury is a major type of occupation related ocular traumas. Indeed, the largest proportion of ocular traumas was penetrating injury (71.36%), followed by blunt injury (22.33%) and explosive injury (11.17%), respectively (Table 1). This is also true for the kids and students, as the major type of traumas for this age group is also penetrating injury caused by pencil or scissors (5 of 8 cases) (Table 1, and data not shown). Of 147 penetrating cases, 69 patients with IOFBs (33.50%) underwent surgeries to remove all the IOFBs successfully for better visual outcomes (Table 2).
Season change adds an additional layer of risk factor to ocular trauma incidents
We also investigated the role of season change in ocular trauma pattern to determine if it also acts as a risk factor. Indeed, ocular trauma incidence exhibited a seasonal pattern, as hot summer months between June and September reached the peak with a significantly higher average ocular trauma incidence compared to other seasons (Fig.1C). Totally there were 94 cases (45.63%，p=0.0170) occurred in summer season between January 2016 and December 2018, which accounts for 32% of ocular trauma incidents in three years (Table 3).
RD and VH are two prevailed types of complications
Complications often occur in ocular trauma patients, which is associated with visual outcomes. It also increases medical cost. In this study we chose to focus on four types of ocular trauma related complications. We found that RD and VH are two common types of complications in ocular trauma patients, which accounts for 10.19% and 8.74% of ocular trauma incidents, respectively, whereas both lens dislocation (3.88%) and traumatic endothphalmitis (1.46%) only occurred in a small portion of patients (Table 4). Extraction of dislocated lens was performed in all the 8 lens dislocation cases (3.88%) (Table 4). For patients with any type of RD, VH, and traumatic endothphalmitis, PPV had to be performed to obtain better visual outcomes either during the first hospitalization or at the follow-up visit within 3 months for a second time surgery. None of the patients received enucleation as the primary procedure.
Location and/or size of injuries determine the vision outcomes
To further understand how injuries may affect the visual outcomes, we analyzed the impact of the location and/or size of injuries on the visual outcomes. We found that most of the injuries are located in the zone I (38.83%), followed by 22.33% of the patients in zone II and 17.96% of the patients in zone III, which is also reflected in wound size with similar incidence, although some patients had overlapping in injury zones and wound sizes (Table 4, Fig. 1D&E). Patients with zones I and II injuries have relative benign visual outcomes, which is also true for patients with wound size smaller than 10mm. However, patients with zone III injury and/or wound size larger than 10mm exhibited poor prognosis, suggesting that location and/or wound size significantly affect the visual outcomes. Most of the patients with zone III injuries and/or wound size larger than 10mm openings in the globe had NLP, a sign of blindness (Table 4).
The correlation between zone/wound size and visual outcomes was strongly supported by the patients’ data in this study. VA is typically used for vision measurement in ocular trauma patients, with level I as the best, and level 4 as the worst. 51.46% of the patients were classified to Level III according to the initial VA, and all level IV patients exhibited either zone III injury or ≥10mm wound size injury (Table 5). Unfortunately, one patient who had zone II injury with 7mm wound size converted to NLP at the end of third month, which was caused by endophthalmitis (Table 5). For most other conditions, however, the visual outcomes were promising after treatment. All the IOFBs were successfully removed through surgeries according to the different segments involved. Three months later, most of the patients had a better final VA to varying degrees except for level IV patients (Table 5, Fig. 1F).