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Metallic foreign body on the optic nerve head
  1. Aditi Mehta1,
  2. Chirag Jain2,
  3. Nazia Anjum1 and
  4. Ramandeep Singh Virk3
  1. 1Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
  2. 2Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Chandigarh, India
  3. 3ENT, Post Graduate Institute of Medical Education and Research, Chandigarh, India
  1. Correspondence to Dr Ramandeep Singh Virk; virkdoc{at}

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A middle-aged man presented with sudden painful loss of vision in the right eye following ocular trauma while working in a nut and bolt factory. At the time of trauma, he was not using protective safety glasses. On examination, he denied perception of light in the right eye, and had a visual acuity of 6/6 in the left eye. A 3 mm scleral laceration was noted near the 12 o’clock limbus; posterior segment details were not visible due to total hyphaema. An A/B scan ultrasonography revealed distorted right globe with a high-amplitude spike of a hyperechoic foreign body on the optic nerve head (figure 1A). Orbital CT confirmed the presence of a hyperdense metallic foreign body on the optic nerve head (figure 1B,C). Despite counselling, the patient refused surgery. He was advised to avoid undergoing MRI scans in the future in view of the metallic foreign body.

Figure 1

(A) Ultrasound of the right orbit demonstrates distorted globe architecture with high-amplitude spike of hyperechoic foreign body on the optic nerve head. (B, C) CT scan of the orbit shows hyperdense metallic foreign body on the optic nerve head (arrow in axial section; B) vis-à-vis normal left optic nerve head (arrow in coronal section; C).

The Birmingham Eye Trauma Terminology System is a useful, standardised method for classifying severe globe trauma.1 Penetrating and perforating globe injuries from missiles and projectiles may lead to entrapped foreign bodies within the globe, ocular coats or the orbit. A particularly rare scenario is lodgement in the optic nerve head, leading to profound vision loss, as seen in our case. Associated optic neuropathy, retinal vascular compromise and siderosis bulbi can be additional mechanisms of vision loss.2 Surgical management involves removal of the foreign body and meticulous repair of the wound. However, removal of a large (>1 mm) central foreign body is seldom useful in regaining vision.3 In such situations, patients should be counselled regarding the risks of sympathetic ophthalmia and siderosis bulbi and also advised to avoid future MRI of the head and neck, lest it dislodges the metallic foreign body intracranially.

Occupational eye injuries may result in ‘preventable’ blindness with an immense socioeconomic impact for the worker as well as the industry. A study from East India on 784 patients reported metallic foreign bodies as the most common cause of occupational eye injury. Lack of safety training and non-compliance with use of safety glasses were associated risk factors.4 Another study, from Norway, reported a significant reduction from 6.09 to 0.42 injuries per million working hours after implementation of mandatory eye protection.5 Compliance to protective eyewear is sometimes limited due to poor fit, blurring of vision, fogging and reduced field of view. A study based on the Victorian Injury Surveillance System reported poor compliance with safety eyeglasses in persons involved in the automotive industry and specifically for the tasks of hammering. They also reported that correct use of safety eyewear could have prevented >60% of injuries.6

Loss of vision from occupational injuries can have devastating psychological consequences and may even result in loss of livelihood.7 Kofi Annan, the former Secretary General of the United Nations, has rightly stated: “Health and safety at work is not just sound economic policy, it is a basic human right.”8

Learning points

  • Foreign bodies should be suspected in all patients presenting with globe injury to the emergency department.

  • The initial investigation of choice is always a CT and never an MRI, especially if the nature of the foreign body (metallic vs non-metallic) is not known.

  • Occupational eye injuries are preventable with use of proper safety glasses; sensitisation of workers and ensuring compliance are paramount.



  • Contributors AM: concept, patient management, manuscript preparation. CJ: concept, patient management, manuscript editing. NA: patient management, manuscript editing. RSV: concept, design, supervision, manuscript editing.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent for publication Obtained.

  • Provenance and peer review Not commissioned; externally peer reviewed.