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To describe the epidemiology of ocular trauma in a tertiary hospital setting in Muscat, Oman
Medical records of all cases of ocular trauma which presented to the Emergency Department at Al-Nahdha Hospital and were seen by the ophthalmology service from January 1, 2013 to June 30, 2013 (6 months) were reviewed to collect data on ocular trauma according to the World Eye Injury Registry initial reporting form which uses the Birmingham Eye Trauma Terminology System.
There were 27,951 patients seen at the Emergency Department and 611 of which were ocular trauma cases (cumulative incidence 2.2% [confidence interval 2.0–2.4]). The mean age of the patients was 23 years and males comprised the majority of the cases (72%). Thirty-two patients had bilateral injury giving a total of 643 eyes injured. More than half of all injuries were caused by either blunt or large sharp objects. The cornea was the most frequently injured tissue (49%), but most injuries were minor in nature. More than three quarters (77%) of all eyes had a visual acuity of 0.3 (LogMAR) or better on presentation. There were 35 eyes (6%) with open globe injuries (OGI) and three-quarters of them occurring in the manual laborers.
Ocular trauma is a common presentation at Al-Nahdha Hospital. Although the majority of trauma cases were minor without any visual disability sequelae, OGI could have been prevented with better ocular protection in the workplace.
Ocular trauma is not a random incident; otherwise, significant worldwide disparities in the incidence of ocular trauma would have simply not existed.
Data on the incidence and prevalence of ocular trauma vary based on study design, geographical and societal factors. In 1998, Négrel and Thylefors reported that worldwide, 1.6 million people were blind secondary to ocular injuries, 2.3 million were left with low visual acuity bilaterally and 19 million with unilateral blindness or low vision. It was also estimated that about 55 million ocular injuries which restrict activities more than 1 day occurred annually, seven hundred and fififty thousand injuries required hospitalization; a third of which were open globe injuries (OGI). Although the above figures are almost 20-year-old, they are still relevant today.
In general, it seems that ocular trauma follows a bimodal age distribution,[2,3] affects more males than females[4,5,6] and occurs more frequently in the lower socioeconomic groups. A higher male preponderance may be related to occupational exposure, participation in dangerous sports and hobbies, alcohol use, and risk-taking behavior.
Worldwide statistics on the epidemiology of ocular trauma had been and are still sparse. Most of the early statistics on ocular trauma came from the United States Eye Injury Registry (USEIR) which was founded in 1988. Subsequently, the USEIR collaborated with the other registries from the world to form the World Eye Injury Registry (WEIR). Standardized reporting forms were developed to standardize data collection on ocular trauma to better compare the magnitude and determinants of ocular trauma between countries.
There is paucity of literature on ocular trauma in the Middle East including Oman. As most ocular injuries are preventable, epidemiological studies are useful in informing prevention of blindness programs.
In this paper, we present the clinical profile of ocular trauma patients presenting to the emergency department at Al-Nahdha Hospital over a period of 6 months in 2013.
Ethics approval for this study was obtained from Al-Nahdha Hospital Research and Ethics Committee and this study was carried out according to the guidelines of the Declaration of Helsinki.
Al-Nahdha Hospital is a main public tertiary referral center in Oman (situated in Muscat) for ophthalmology, ENT, dermatology and dental. The Emergency Department at Al-Nahdha Hospital is a general emergency department covering all sub-specialties of medicine. The ophthalmology on-call is an on-site 24 hour service. All cases of ocular trauma (minor and major) from January 1, 2013 to June 30, 2013 that were seen by the ophthalmology service were included in the study.
Information obtained from the medical records followed the WEIR initial reporting form [Appendix 1]. Injuries were classified according to the Birmingham Eye Trauma Terminology system. Due to the retrospective nature of this study, some data such as protective eyewear use in all types of injuries, place of injury and bystander injury were missing. Complete or close to complete data were available for demographics, source of injury, main tissue involved, visual acuity (reported in this study in LogMAR), and the initial diagnosis.
The cumulative incidence of ocular trauma in Al-Nahdha hospital was calculated as the number of ocular trauma cases over the total number emergency cases seen (ocular and nonocular).
Simple descriptive statistics were used and the data were analyzed using Statistical Package for Social Sciences (SPSS 21) (IBM, NY, USA).
A total of 27,951 cases were seen at the Emergency Department (ocular and nonocular) and 611 of which were ocular trauma cases with a cumulative incidence of 2.2% (95% confidence interval 2.0–2.4). Thirty-two patients had bilateral injuries giving a total of 643 eyes injured. The demographic characteristics of the patients are shown in Table 1. Most injuries occurred in males and those in the age-groups of 2–15 and 16–30 years with a mean age of 23 years.
Blunt and large sharp objects accounted for most of the injuries [Table 2]. The cornea, conjunctiva and eye lids were the most injured ocular tissues [Table 3]. Partial thickness corneal wounds accounted for 83% of total corneal injuries. Most injuries were minor with an excellent visual outcome. More than three quarters (77%) of all eyes had visual acuity of 0.3 (LogMAR) or better on presentation.
Thirty-five eyes (6% from the total number of eyes injured) had OGI [Figure 1]. None of these OGI patients had protective glasses at the time of injury. Most OGI occurred in males (90%) with a mean age of 31 years. Four children (<16-year-old) had OGI (1% out of all childhood ocular injuries and 11% out of OGI). Twenty-three injuries (66% out of all OGI) were work related, all except one occurring in the non-Omani population, many of which are involved in manual labor.
This study found that the cumulative incidence of ocular trauma at Al-Nahdha Hospital was 2.2%. Most injuries occurred in males with a mean age of 23 years. Blunt and large sharp objects accounted for most of the injuries with the cornea being the most affected tissue. OGI occurred in 6% of patients with a mean age of 31 years and mostly work related occurring in the non-Omani manual labor population.
This study is the first study in Oman to describe the epidemiology of ocular trauma. It is also the first study in the region to our knowledge to use the WEIR to collect data on all minor and major eye injuries.
Our study found that more than two-thirds of ocular injuries occurred in men, more than 50% of injuries were seen in the most productive age groups those 16–45 years of age and most severe injuries occurred in those with lower socioeconomic status doing mostly labor work. Other studies around the world found similar findings to our study in that men, the young and those with lower socioeconomic status are affected more.[6,7,11] These higher rates seem to be due to the nature of occupational exposure, participation in dangerous sports and hobbies, alcohol use, and risk-taking behavior.
Contrary to the popular belief, a significant shift of injury setting from the workplace to the home, was noted first by USEIR researchers in the context of a large, multicenter study. However, the proportion of workplace injuries, although relatively low, result in more extensive tissue damage. Complete data on the place of injury were not available for all the injuries in our study, but it was noted that the majority of OGI were work related and none of the patients were using any protective eyewear at the time of the incident.
Luckily, most ocular trauma results in minor injuries without any major visual disability. Our study found that 94% of all ocular injuries were closed globe. This is a trend which is also seen in other parts of the world.[12,13]
The frequency of ocular trauma in the non-Omani population is likely to be falsely low in this study. The 2013 mid-year population of Muscat was estimated to be 1,155,861 people (Omanis = 451,652 and Non-Omanis = 704,209 people). Given the latter and the majority of non-Omanis are manual laborers and of lower socioeconomic status, one would expect that the frequency of ocular trauma in the non-Omani population to be higher. A possible explanation for this observation is that the treatment at Al-Nahdha Hospital is free for Omanis and governmental employees only. Thus, many non-Omanis with minor injuries might not go to the hospital at all or elect to be treated at other private health care centers, especially those that charge lesser fees for treatment. Nevertheless, the majority, if not all severe eye injuries, are usually referred to tertiary care facilities such as Al-Nahdha Hospital for management and thus our data are more representative of severe eye injuries such as OGI. The higher incidence of OGI in the Non-Omani population is expected because of the nature of their jobs as well as the majority being in the susceptible age groups.
This study is limited by its relatively small size for internal sub-group comparison and the retrospective design. Data obtained relied on what was already documented. Therefore, there were missing data such as protective eyewear use in all types of injuries, place of injury, bystander injury which rendered analysis and inclusion of such data in this study. Although Al-Nahdha Hospital is a main tertiary eye hospital in Oman, the statistics are not representative of the whole country. Many minor ocular trauma cases are treated by the primary health-care physicians. Other injuries which might be major may be treated in secondary and other tertiary hospitals. However, the characteristics of patients reported in this study may be similar in other non-industrial parts of Oman. Another limitation of this study is that it did not include the months of the summer holiday in Oman (June-September) in which the rate of ocular injuries may be expected to be higher.
This study has a number of implications nationally and internationally. On a local level, there needs to be collaboration between the different health-care facilities to collect population-based data and informing the need for establishing an ocular trauma registry whereby standardization of documentation is possible.
Unfortunately, the young are more at risk of ocular trauma, and this translates into a higher economic burden to the country at large. Work related injuries, especially among the working class (mostly non-Omanis and with lower socioeconomic status) are preventable, and there needs to be a public health initiative to promote the importance of protective eyewear. In addition, our study found that 28 cases (4.6%) of ocular trauma occurred in infants. This may signify the importance of health education among mothers, especially during their visits to primary care facilities for vaccination purposes.
On the international level, standardized population-based data on ocular trauma is essential to produce robust data to compare data and prevent eye trauma. A good example is the cancer registries around the world. They have come a great way in terms of data collection and research on cancer.
In conclusion, ocular trauma, although a common presentation at Al-Nahdha Hospital, mostly does not result in visual disability. However, the small number of open globe injuries with resultant significant morbidity may be prevented with better awareness and protective eye wear.
There are no conflicts of interest.
The authors would like to thank the staff at the Emergency Department and the Medical Records Department for their support in the execution of this study.