Posters

When IOFB meets MRI

Poster Details

First Author: C.Fan HONG KONG

Co Author(s):    C. Au   L. Iu   T. Ko              

Abstract Details

Purpose:

A case report of a patient presented with corneal edema after MRI brain suspecting having a metallic intraocular foreign body(IOFB)

Setting:

Tung Wah Eastern Hospital, Hong Kong

Methods:

A case report of a 90-year-old man who had a history of ocular trauma 40 years ago. MRI brain was done for his stroke. During MRI, a metallic IOFB was suspected. Patient soon presented to ophthalmology department. His visual acuity was finger count. He had severe corneal edema and aniridia. IOFB could not be seen in examination but siderosis was noted in inferior limbal-corneal area. Gonioscopy failed. UBM showed suspicious echogenicity in inferior angle. CT orbit suggested metallic IOFB in front of intraocular lens. Removal of IOFB was done in view of siderosis and persistent corneal edema.

Results:

Endoscope used for endoscopic cyclophotocoagulation(ECP) is the only available intra-ocular endoscope at our department. It was used to guide IOFB removal. The endoscope was inserted through a wound opposite to IOFB to help direct visualisation and localisation of IOFB. Visocelastic was injected through a paracentesis to displace the IOFB centrally. A 23G vitreoretinal serrated forceps was used to engage IOFB after extending the main wound. Two weeks after operation, patient's cornea was less edematous and visual acuity improved to 0.2.

Conclusions:

Metallic IOFB in anterior segment could cause corneal edema and traumatic aniridia if patient undergoes MRI which induces mechanical vibration of foreign body and heat dissipation resulting in tissue damage. Various imaging modalities including computer tomography and ultrasound biomicroscopy helps to locate IOFB when corneal edema precludes detailed examination. Surgical removal of angular IOFB remains challenging especially in the presence of corneal edema. Endoscopy not only facilitates direct visualisation and removal of IOFB but also increases safety and efficiency  of surgery with minimal trauma to ocular tissue.

Financial Disclosure:

None