Prolonged Button Battery Exposure Leading to Severe Ocular Injury without Heavy Metal Poisoning.

Introduction: Prolonged exposure to a complete button battery can cause severe tissue necrosis in the eye and permanent impairment of visual function. The main mechanism of injury is the current generated by the hydrolysis of tissue fluid at the negative electrode and the production of hydroxide ions.

Case presentation: A 3-year-old girl went to the local hospital because of swelling and pain in her right eye of 12-h duration. The local doctor performed an orbital CT (computed tomography) scan and found a foreign body between the right eyelid and the eyeball. The foreign body was removed immediately under general anesthesia. In addition, it was found that the foreign body was a button battery, but it prolonged 39 h from the onset of the child's symptoms. The child underwent a second operation in our hospital and received amniotic membrane transplantation combined with conjunctival flap coverage. Topical corticosteroid and antibiotic eye ointment were continued for 3 months after surgery. Local pigmentation was seen, there was no symblepharon, but the cornea was still opaque and the visual acuity was only FC (finger count). In this particular case, heavy metal testing conducted on the child's blood fortunately revealed that the levels were within the normal range.

Conclusion: Early detection and urgent removal of button battery are crucial in order to minimize exposure time. We should also be concerned about heavy metals in the blood. Children should be kept away from button batteries as much as possible to avoid such injury.