Electrophysiological findings in delayed discovery of a metallic intraocular foreign body in a child: case report

Purpose To report a case of a child with strabismus and delayed discovery of a metallic intraocular foreign body with good recovery of visual acuity and stereopsis with 36-month follow-up. Methods A 4-year-old girl was evaluated due to exotropia of right eye initiated 9 months before with progressive worsening. Visual acuity was 1.00 logMAR (20/200) in the right eye and 0.00 logMAR (20/20) in the left eye. Anterior segment evidenced a small paracentral corneal leukoma, posterior synechia and mild lens opacity in the temporal quadrant only in the right eye. Fundus examination in the right eye identified the presence of an intraocular foreign body, with appearance of metallic components surrounded by retinal pigmented endothelial cells atrophy. Full-field electroretinography (ERG) showed reduced amplitudes and delayed implicit times for both rods and cones in the affected eye. All tests were normal in the fellow eye. Results Pars plana vitrectomy was promptly performed in the right eye, followed by phacoemulsification with intraocular lens implantation 4 months later due to worsening of the lens opacification. The full-field ERG was repeated after the surgical procedures. The ERG showed mild worsening of all responses in the right eye. After 36 months of follow-up, visual acuity was 0.20 logMAR (20/32) with improvement of the ocular misalignment and with 60 s of arc stereopsis with ERG responses unchanged. Conclusion In this young girl perforating ocular trauma with metallic material was lately diagnosed with strabismus as a sign of alert. Prompt surgical intervention and proper management were essential to provide reasonable visual function including some degree of stereopsis, even though retinal dysfunction characterized by ERG was persistent.