27.2  Intraocular Foreign Body

1. Evaluation

The identification of intraocular foreign bodies (IOFB) is a critical step in the evaluation of penetrating ocular injuries.[1,2] The visual acuity, pupil examination, intraocular pressure, and extent of injury visible on examination should be carefully documented (Figure 27.2.1).[3,4] All patients should undergo thin-cut 3-mm non-contrast orbital CT scans prior to surgery.[5] Gentle B-scan ultrasonography may provide additional useful information if visualization of the fundus is obscured. Concern for expulsion of intraocular contents may preclude B-scan ultrasonography until the globe is closed.[6,7]

Thompson JT, Parver LM, Enger CL et al. Infectious endophthalmitis after penetrating injuries with retained intraocular foreign bodies. National Eye Trauma System. Ophthalmology 1993; 100:1468-1474.

Zhang Y, Zhang M, Jiang C et al. Intraocular foreign bodies in china: clinical characteristics, prognostic factors, and visual outcomes in 1,421 eyes. Am J Ophthalmol 2011; 152:66-73 e61.

Guven S, Durukan AH, Erdurman C et al. Prognostic factors for open-globe injuries: variables for poor visual outcome. Eye (Lond) 2019; 33:392-397.

Fujikawa A, Mohamed YH, Kinoshita H et al. Visual outcomes and prognostic factors in open-globe injuries. BMC Ophthalmol 2018; 18:138.

Dass AB, Ferrone PJ, Chu YR et al. Sensitivity of spiral computed tomography scanning for detecting intraocular foreign bodies. Ophthalmology 2001; 108:2326-2328.

Rubsamen PE, Cousins SW, Winward KE et al. Diagnostic ultrasound and pars plana vitrectomy in penetrating ocular trauma. Ophthalmology 1994; 101:809-814.

Deramo VA, Shah GK, Baumal CR et al. Ultrasound biomicroscopy as a tool for detecting and localizing occult foreign bodies after ocular trauma. Ophthalmology 1999; 106:301-305.

2. Management

Once an IOFB is identified, the urgency and approach to its management depends on numerous factors, including:

  • Composition of the foreign body. Vegetable matter poses a greater risk of endophthalmitis. Iron and copper-containing foreign bodies are at risk of developing siderosis or chalcosis, respectively. Other metals can also damage the intraocular structures including aluminum, zinc, iron, steel, nickel, and mercury; while cilia, glass, plastic, and gold are relatively inert (Figure 27.2.2)[2,8]
  • Location, size, and repair of entry and exit wounds
  • Association with other ocular injuries, which may include corneal or scleral perforation, cataract, ocular hypertension or hypotony, phacodonesis, iridodonesis, endophthalmitis, hyphema, vitreous and suprachoroidal hemorrhage, and retinal detachment[2,9]
  • Visualization of the fundus

Zhang Y, Zhang M, Jiang C et al. Intraocular foreign bodies in china: clinical characteristics, prognostic factors, and visual outcomes in 1,421 eyes. Am J Ophthalmol 2011; 152:66-73 e61.

Khani SC and Mukai S. Posterior segment intraocular foreign bodies. Int Ophthalmol Clin 1995; 35:151-161.

Yannuzzi NA, Sridhar J, Flynn HW Jr, Gayer S, Berrocal AM, Patel NA, Townsend J, Smiddy WE, Albini T. Current Trends in Vitreoretinal Anesthesia. Ophthlamol Retina. 2019 Sep;3(9):804-805.

McClellan AJ, Daubert JJ, Relhan N, Tran KD, Flynn HW, Gayer S. Comparison of Regional vs. General Anesthesia for Surgical Repair of Open-Globe Injuries at a University Referral Center. Ophthalmol Retina. May-Jun 2017;1(3):188-191.

4. Primary Closure

Unless the IOFB has entered the eye through the cornea, conjunctival peritomy should be performed to evaluate the extent of the scleral injury. Prolapsed uveal tissue should be gently reposited into the eye, or excised, dependent upon the viability of the tissue. Prolapsed vitreous or lens fragments are generally cut flush with the corneoscleral wound. The wounds should be closed completely prior to intraocular manipulation (See Chapter 27.1 Open Globe Injuries).

5. Visualization

If the visualization of the fundus is impaired (e.g. hyphema, cataract), this needs to be addressed next. As always, if an infusion cannula cannot be visualized through the pupil, an anterior chamber infusion line should be placed until this has been rectified. Anterior chamber washout and/or lensectomy may be required. If lensectomy is performed and there is adequate zonular support, the sulcus should be left for future placement of an intraocular lens. In cases of more advanced retinal disease, the patient may be left aphakic and the capsule removed.

6. Vitrectomy

Vitrectomy can only proceed safely once there is sufficient view through the pupil of the intraocular instruments.[12,13,14] A long infusion line (e.g. 6 mm) can be placed trans pars plana and visualized through the pupil to avoid inadvertent suprachoroidal infusion. If there is concern for an occult retinal detachment or choroidal effusion or hemorrhage, then it is often preferable to assess the situation with a light-pipe prior to creation of the third sclerostomy.

Although the IOFB will often be addressed last, the nature of the posterior segment injury and the location of the IOFB should be determined. Next, a core vitrectomy is performed, the hyaloid is elevated if a PVD is not present and it is deemed safe to do so (this might be skipped in a young patient to avoid iatrogenic tears resulting from a very adherent vitreous), and a peripheral vitrectomy with scleral depression is performed to simultaneously evaluate for anterior pathology.

Peyman GA, Raichand M, Goldberg MF et al. Vitrectomy in the management of intraocular foreign bodies and their complications. Br J Ophthalmol 1980; 64:476-482.

Wani VB, Al-Ajmi M, Thalib L et al. Vitrectomy for posterior segment intraocular foreign bodies: visual results and prognostic factors. Retina 2003; 23:654-660.

Sborgia G, Recchimurzo N, Niro A et al. 25-Gauge Vitrectomy in Open Eye Injury with Retained Foreign Body. J Ophthalmol 2017; 2017:3161680.

7. Removal of IOFB

Determine the size and composition of the IOFB. A pars plana incision will need to be created with an MVR (or keratome) blade that is at least the minimum dimension of the IOFB. The IOFB may require removal through the limbus or through a clear corneal wound (if the patient is aphakic). These steps should be performed as the final steps in order to minimize hypotony (Figure 27.2.3).

Multiple instruments can be used to lift the IOFB off the retina including IOFB forceps (such as the Rappazzo IOFB forceps), a soft tip cannula, or a magnet.[15] If linear, the IOFB should be grasped near one end so that it is easier to remove (Figure 27.2.4). A chandelier can be placed to permit bimanual reorientation. If the IOFB is embedded in retina and/or choroid, then endodiathermy around the retinal entry site and elevation of the intraocular pressure may assist in hemostasis. For magnetic IOFBs, on occasion there may be a role for use of an intraocular or external magnet.

Chow DR, Garretson BR, Kuczynski B et al. External versus internal approach to the removal of metallic intraocular foreign bodies. Retina 2000; 20:364-369.

8. Scleral Buckle

Patients with an IOFB have a high risk of retinal detachment. If this is present or likely to develop, consider placing a scleral buckle at the time of primary closure of the globe or IOFB removal.[16,17,18]

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Westmead Eye Manual
This invaluable open-source textbook for eye care professionals summarises the steps ophthalmologists need to perform when examining a patient.

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