Retained metallic intraocular foreign bodies (IOFBs) may cause toxic effects such as cataract and retinal damage. We describe an unexpected course of siderosis in a patient who had undergone removal of an IOFB shortly after injury and then had siderosis develop, which subsequently disappeared spontaneously. To our knowledge reversal of siderosis has not been previously reported.
A 32-year-old man was seen with an IOFB in the left eye after he had hammered a nail. On admission, visual acuity was 20/20 OD and 20/30 OS. Findings from examination of the right eye were unremarkable. Findings from biomicroscopy of the left eye were normal. A 2-mm scleral laceration was noted 3 mm temporally to the limbus. Funduscopy disclosed a metallic IOFB impacted in vitreal hemorrhage nasally to the optic disc. The entry wound was repaired immediately, and the next day laser photocoagulation was applied around the IOFB. After 5 days, pars plana vitrectomy and removal of the IOFB via sclerotomy, using a foreign-body forceps, were performed. Visual acuity returned to 20/20 OS, the lens remained clear, the retina was attached, and laser scars were seen nasally to the optic disc.
Three years later the patient complained of a gradual decrease of vision in the left eye. Examination findings revealed that the right eye had remained stable, whereas visual acuity in the left eye had deteriorated to counting fingers. The 2 pupils were of equal size, but the left eye showed a relative afferent pupillary defect and heterochromia with a rust-colored discoloration of the iris (Figure 1, A). Fine rustlike deposits were seen on the left interior lens as well as progressive cataract (Figure 1, B). Findings from funduscopy through the cataract disclosed a flat retina. Results of electroretinography revealed markedly reduced amplitude even after moderate-intensity stimulus. Computed tomographic findings showed no IOFB. Results of repeated diagnostic x-ray spectrometry demonstrated no metal dissolution in the eye. The patient underwent an uneventful left extracapsular cataract extraction with intraocular lens implantation, after which visual acuity improved to 20/30. Funduscopy findings showed a slight pallor of the optic disc, attenuation of retinal vessels, and fine yellow deposits around the fovea. The visual field examination results were normal, but findings on electroretinography remained unchanged. Although findings from repeated x-ray spectrometry disclosed no metal dissolution in the eye, heterochromia persisted and new, fine, rustlike deposits were seen on the intraocular lens (Figure 1, C). Two years later (5 years from initial admission) he returned because vision in that eye had again deteriorated. Reexamination showed a visual acuity of 20/200 OS due to opacification of the posterior lens capsule. However, the rust-colored discoloration of the left iris and the resulting heterochromia had disappeared (Figure 2). The patient underwent Nd:Yag capsulotomy and visual acuity improved to 20/30.
The course of siderosis. A, Heterochromia is seen with rust-colored discoloration of the left iris 3 years after injury. B, Rustlike deposits on the anterior surface of the left lens 3 years after injury. C, Rustlike deposits on the anterior surface of the implanted intraocular lens 4 years after injury.
Disappearance of the brownish discoloration of the left iris 5 years after injury.
This report describes an unusual case in which, despite the removal of an IOFB, siderosis unexpectedly developed but was subsequently arrested and resolved spontaneously. The course this condition took would appear to contraindicate the commonly recommended treatment involving IOFB removal concomitantly with or soon after repair of the entry site,1,2 to avoid the development of siderosis and its possible devastating effects. Our patient underwent vitrectomy with thorough cleansing of dust particles from the eye shortly after injury, and the eye exhibited no metal dissolution in the eye on repeated diagnostic x-ray spectrometry testing. He nevertheless developed siderosis manifested by heterochromia, cataract, and retinal abnormalities. Furthermore, even after the extraction of the lens and washing of the anterior chamber the siderosis continued to progress, manifested by an accumulation of rustlike deposits on the implanted lens. Siderosis can occur in cases of retained IOFB, especially in the absence of clear ocular trauma.3 However, it is very unusual to have siderosis develop after extrusion of the IOFB. Even more unexpected was the fact that the siderosis was arrested and resolved spontaneously. One possibility is that the short delay of 5 days in the removal of the IOFB contributed to the development of siderosis. Another possibility is that there was a second minute foreign body that was initially undetected and caused siderosis. Although results of electroretinography remained abnormal, the final outcome in visual acuity was good. Other authors4 have also reported a favorable outcome even in cases with a retained metallic IOFB and have elected to do follow-up on the retained IOFB with use of serial electroretinography and spectrometry.
In summary, this report describes a favorable outcome of siderosis.
Pollack A, Oliver M. Reversal of Siderosis. Arch Ophthalmol. 1998;116(5):678-679. doi: