INTRODUCTION

A superficial corneal foreign body (FB) is the most common and preventable eye injury⁽¹⁾. Metallic corneal FBs resulting from occupational accidents are often seen in construction and metal industry workers⁽²⁾. FBs can decrease the quality of vision by causing scars on the visual axis and secondary infections ranging from keratitis to endophthalmitis^(3,4). The health care costs for these injuries are another problem as they create an economic burden⁽⁵⁾.

Prevention of FB accidents and their potentially serious consequences are certainly possible, and the investment in their prevention is easily justified. Wearing appropriate protective goggles prevents about twothirds of these accidents⁽⁶⁾. In addition to the use of personal protective measures, it is important to improve workplace standards and provide appropriate training for supervisors⁽⁷⁾.

Approximately 36% workers in Turkey are unregistered⁽⁸⁾. Unregistered workers do not qualify for governmentfunded health care after an occupational accident nor do they take advantage of their legal rights. In this study, we investigated the demographic characteristics, eye protection measures, approaches to FBs, and the level of knowledge about corneal FBs in a working population in Turkey.

METHODS

This study was approved by the hospital's institutional review board and adhered to the tenets of the Declaration of Helsinki. This prospective study evaluated 100 consecutive patients who presented with metallic corneal FBs to the eye clinic at Diyarbakir Training and Research Hospital between December 2012 and May 2013. Verbal consent was obtained from the patients before they completed the questionnaire.

Patients were evaluated with a siltlamp biomicroscope. FBs and rust rings were removed using a 26gauge needle under topical anesthesia. A topical antibiotic treatment (Tobramycin, four times a day) was prescribed after FBs were removed. The locations of the removed FB, rust marks, and any existing corneal scars from previous FBs were noted.

We recorded demographic information for each patient, which included age, gender, education, and type of social insurance. The following data also were obtained through our questionnaire: business sector and occupation at the time of incident, number of years of work in the present sector, time between the incident and first visit to an ophthalmologist, number of previous similar eye injuries, availability of protective goggles at work, protective goggle use during the incident, attempted FB removal by the patient, technique used if selfremoval was attempted, the number of workers in the workplace, and presence of an occupational physician. To determine a worker's level of knowledge about corneal FB injuries, we asked whether they understood that repetitive FB injuries can cause serious visual impairment and FB removal by themselves can cause serious and infection.

Statistical analyses were performed with Statistical Program for Social Science (SPSS) version 15 (SPSS, Chicago, Illinois, USA). The statistical calculations included descriptive statistics, chisquare test, and SpearmanBrown correlation. The data are presented as the mean ± standard deviation.

RESULTS

We examined 100 patients who were diagnosed with a metallic corneal FB. All patients were male and had a mean age of 32.46 ± 1.03 years (age range: 1457 years; Table 1). Six percent of patients had not received formal education, 56% had completed primary school, 23% had completed secondary school, 15% had graduated from high school or an equivalent institution. Fortyeight percent of the patients had a green card (a document given to lowincome individuals without social insurance to allow them to use the public health care service in Turkey) and 7% had no social insurance; thus, 55% patients were unregistered workers, whereas only 45% were registered.

Most patients (59%) were working in the metal industry sector, 25% were working in the construction sector, and 8% were working in automotive repair sector (Table 2). Most injuries (65%) occurred when the patient was cutting metal (65%), 22% occurred with welding, and 13% had an unknown origin (Table 3). The number of FB injuries increased significantly with number of years at work in the metal industry and construction sectors (p<0.001, p=0.005). Sixtyfour percent of the patients reported that protective goggles were available in their workplace; however, 57% were not wearing goggles at the time the accident occurred, and 43% were injured despite goggle use. There was no significant correlation between the education level and goggle use (p=0.470).

We examined the patient's knowledge about corneal FBs and his approach to treatment. The mean duration between the injury and the first visit to an ophthalmologist was 2.16 (±0.26) days and ranged between 0 and 21 days. We found that 52% patients attempted FB removal by themselves. The materials used for the removal were currency notes (31%), napkins (7%), a cloth (4%), and miscellaneous items (10%) such as a needle or toothpick, which can cause further injury (Table 4). One patient presented with a deep central corneal scar that caused a secondary infection after he had removed the FB by himself. There was no significant correlation between the education level and whether patients attempted to remove FBs by themselves, or between understanding the potential harm in selfremoval and understanding repetitive FB injuries can harm visual acuity (p=0.079, p=0.435, p=0.329).

Only 8% workplaces provided an occupational physician service; however, the presence of an occupational physician in the workplace did not affect the availability of protective goggles (p=0.580), the workers' attitudes about wearing goggles (p=0.341), whether workers attempted to remove FBs by themselves (p=0.284), or understanding the harm of selfremoval of FBs p=0.764).

The locations of the FBs were central (16%), paracentral (61%), and peripheral (23%). Rust marks were present in 26% patients after FBs were removed. Corneal scars due to previous FB injuries were present in 58% patients and were located in the central (5%), paracentral (42%), and peripheral (11%) regions.

DISCUSSION

Corneal injury due to a metallic FB is a common occupational health injury in Turkey and worldwide. Occupational injury by corneal FB comprises 35%58% of all ocular trauma^(9,10), and more frequently affects young men⁽¹¹⁾. These preventable injuries cause additional burden on the national economy, adjustment problems, and psychological morbidity^(5,12).

In a study conducted in Turkey, metal fragments caused 37% of all superficial corneal FB injuries, but the occupational injury ratio and the causes of injury were not defined in that study⁽¹³⁾. In our study, occupational injuries occurred during metal cutting (65%) or welding (22%), whereas 13% had an unknown origin. Metal cutting and welding are frequent tasks in the metal industry; hence, most FB eye injuries occurred in this sector (59%), which was followed by the construction sector. In a similar study, 70% corneal FB injuries occurred in the metal cutting industry⁽¹⁴⁾. In a Canadian study, 21% eye injuries occurred during welding⁽¹⁵⁾. Thus, the people working in these sectors comprise the largest risk group.

In our patient population, 52% patients attempted to remove the FBs themselves using materials that can damage and infect the cornea. In a study conducted by Filho et al., several microorganisms apart from the normal conjunctival flora were isolated from 20% conjunctival swabs of patients with corneal FBs⁽⁴⁾. In a similar study, 14% positive bacteria cultures were obtained from patients with corneal FBs⁽⁵⁾. Corneal FBs themselves can spread infections, and selfremoval of an FB with contaminated and potentially traumatic materials can increase the risk of corneal infections. These secondary corneal infections affect the quality of vision and can cause corneal scarring. In one of our patients, a deep corneal scar caused vision loss that resulted from a corneal abscess that formed after selfremoval of an FB. In an Australian study that included 100 patients with metallic corneal FBs, one patient presented with bacterial keratitis, although it was not indicated whether the patient attempted FB removal⁽¹¹⁾.

Metallic FBs usually leaves a rust ring in the cornea often causes a white scar to form that can decrease visual quality. The appearance of a rust ring indicates an FB was embedded in the cornea for >1224 h⁽¹⁶⁾. Therefore, visiting an ophthalmologist after an injury as soon as possible is crucial. Among our patients, the mean duration between the injury and their first visit to an ophthalmologist was 2.16 (±0.26) days after the injury. A rust ring remained in 26% patients and a corneal white scar attributed to a previous FB was observed in 58% patients. The high frequency of scarring observed in our patients likely resulted from the delay in seeking treatment from an ophthalmologist and the attempt of removing the FB with traumatic materials.

Using protective goggles, especially those with top and side shields, may have prevented twothirds of these FB injuries⁽⁶⁾. Despite wearing goggles, 43% patients sustained injuries. In a similar study, 45% patients sustained an eye injury while wearing some form of eye protection⁽¹¹⁾. In this context, new designs should be implemented and workplace standards should be adjusted to increase the protective capabilities of goggles⁽⁷⁾.

According to the current occupational health and safety board regulations in Turkey, an occupational physician is necessary in sectors that employ at least 50 workers. The workplaces of only 8% patients in the present study had an occupational physician. The dominance of smallscale workplaces and 55% workers being unregistered might explain this low ratio. Unfortunately, the presence of an occupational physician has not been effective for the procurement of protective goggles at workplaces or the attitudes of workers toward goggle use. In addition, the presence of an occupational physician has not increased the workers' level of knowledge about ocular safety. In addition, no correlation was found between education and the knowledge of the subject. According to these data, occupational physicians should be informed about the importance of preventative measures against eye injuries, and they should inform workers about the subject without considering the workers education status.

In Turkey, approximately 36% employees are unregistered⁽⁸⁾. In the present study, this percentage was even higher at 55%. These unregistered workers are unable to take advantage of legal rights for accidents occurring at work. In addition, workers do not have social insurance and are ineligible for free health care. This situation can force workers to remove the FBs by themselves rather than seek care from an ophthalmologist.

CONCLUSION

Workplaces with a high risk for corneal injury should be identified, occupational physicians and workers should be educated about such eye injuries, and eye protective measures should be increased. Furthermore, the necessary legal arrangements should be made to decrease the number of unregistered workers.