Ultrasound biomicroscopy in two cases of ocular siderosis with secondary glaucoma

Acta OphthalmologicaVolume 88, Issue 1 p. e1-e2 Free Access Ultrasound biomicroscopy in two cases of ocular siderosis with secondary glaucoma Chiara Sangermani, Chiara Sangermani Institute of Ophthalmology, University Hospital of Parma, ItalySearch for more papers by this authorPaolo Mora, Paolo Mora Institute of Ophthalmology, University Hospital of Parma, ItalySearch for more papers by this authorCristina Mancini, Cristina Mancini Institute of Human Pathology and Histology, University Hospital of Parma, ItalySearch for more papers by this authorMarco Vecchi, Marco Vecchi Institute of Ophthalmology, University Hospital of Parma, ItalySearch for more papers by this authorStefano A. Gandolfi, Stefano A. Gandolfi Institute of Ophthalmology, University Hospital of Parma, ItalySearch for more papers by this author Chiara Sangermani, Chiara Sangermani Institute of Ophthalmology, University Hospital of Parma, ItalySearch for more papers by this authorPaolo Mora, Paolo Mora Institute of Ophthalmology, University Hospital of Parma, ItalySearch for more papers by this authorCristina Mancini, Cristina Mancini Institute of Human Pathology and Histology, University Hospital of Parma, ItalySearch for more papers by this authorMarco Vecchi, Marco Vecchi Institute of Ophthalmology, University Hospital of Parma, ItalySearch for more papers by this authorStefano A. Gandolfi, Stefano A. Gandolfi Institute of Ophthalmology, University Hospital of Parma, ItalySearch for more papers by this author First published: 28 January 2010 https://doi.org/10.1111/j.1755-3768.2009.01521.xCitations: 12 Paolo MoraInstitute of OphthalmologyUniversity Hospital of ParmaVia Gramsci 1443100 ParmaItalyTel: + 39 0521 703104Fax: + 39 0521 292358Email: [email protected] AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Editor, Siderosis bulbi is a disease caused by a retained intraocular iron-containing foreign body (IOFB). A history of ocular trauma combined with heterochromia, mydriasis, pigmentation of the anterior chamber structures and a reduced electroretinographic response all provide an inkling of the diagnosis (Sneed & Weingeist 1990). Affected eyes can often present with a severe increase in intraocular pressure (IOP) (Talamo et al. 1985). A precise radiological and/or echographic localization of the IOFB, ideally supported by histological analysis of a biological sample, are vital to the confirmation of the disease. This article describes two cases of secondary glaucoma caused by the retention of an IOFB. An ultrasound biomicroscopy (UBM) examination (UBM Model P40; Paradigm Medical Industries Inc. Salt Lake City, UT, USA) was performed in both patients and the findings are discussed below. Patient 1 An 11-year-old boy received a fragment of a bullet in his left eye. The sclera was promptly sutured but a small IOFB was overlooked. Two months later, the injured eye presented traumatic cataract with uveitis. On gonioscopy, the irido-corneal angle showed conspicuous rust-brown pigmentation in the trabecular meshwork (TM) and the IOP was 30 mmHg on average. Computed tomography showed the presence of a piece of iron in the nasal ora serrata (about 2 mm in length), which was removed surgically via pars-plana vitrectomy with polydimethylsiloxane (PDMS) tamponade and phacoemulsification of the lens. PDMS was removed uneventfully after 1 month. However, after one more month, trabeculectomy with mytomycine-C application was necessary to achieve satisfactory control over IOP. The preoperative UBM showed an unusually high reflectivity in the deep angular stroma compared to the regular echographic pattern of the fellow eye (Fig. 1A–D). Histological examination of a TM sample, taken during a subsequent surgical revision of the filtering bleb, confirmed the diagnosis of ocular siderosis. Figure 1Open in figure viewerPowerPoint Ultrasound biomicroscopy: patient 1. The images show anomalous high-ultrasound reflectivity of the deep angular tissues (circle) in the injured eye, in both the temporal (A) and nasal (B) quadrants. The fellow eye, conversely, shows a completely normal aspect in the corresponding quadrants (C, D) – same `gain'. Patient 2 A 27-year-old man suffered an injury to his left eye while he was hammering metal. The IOFB, initially misdiagnosed, was found in the superior ora serrata during a pars-plana vitrectomy with phacoemulsification of the lens performed 3 months after the trauma. On gonioscopy, the TM pigmentation was much more brown and dense than in the right (healthy) eye. After four more months, filtering surgery became necessary to control the IOP increase. The histological evaluation of a sample of iris and TM was positive for iron staining and showed alterations compatible with siderosis bulbi. The preoperative UBM findings were remarkably similar to those obtained in the patient described previously. The aetiopathogenesis of secondary open-angle glaucoma related to ocular siderosis has often been ascribed to trabecular fibrosclerosis, probably because of the direct toxic effect of iron ions (Appel & Barishak 1978). In the first presented case, severe glaucoma developed 2 months after the trauma with the metal foreign body still in the eye. In the second case it appeared approximately 7 months later, with an initial 3-month retention of the IOFB. IOP elevation did not resolve in either patient after IOFB removal. The UBM showed an anomalous high reflectivity in the deep angular layers of the affected eyes compared to the normal imaging in the fellow eyes. In patient 1, such findings could have been 'biased' by a PDMS leaking into the anterior chamber after vitrectomy but, in our experience, this situation presents on UBM with an irregular, highly reflecting band localized on the aqueous surface of the TM and not deep within the stroma. Therefore, it is reasonable to infer that UBM alterations in both patients could depend either directly on metallic particles imprisoned in the TM or indirectly on the consequent fibrotic reaction. The ability of UBM to detect fine abnormalities in the anterior segment of the eye has been confirmed recently (Sbeity et al. 2008). Furthermore, it is reasonable to surmise that the usefulness of optical coherence tomography will soon lead to it being proposed for the study of anterior-segment alterations (Kalev-Landoy et al. 2007). However, in the cases presented here, UBM proved wholly effective in revealing structural changes in the angular stroma through anomalous hyper-reflectivity, and thus might well be exploited as an aid where clinical suspicion of ocular siderosis exists. References Appel I & Barishak YR (1978): Histopathological changes in siderosis bulbi. Ophthalmologica 176: 205– 210. Kalev-Landoy M, Day AC, Cordeiro F & Migdal C (2007): Optical coherence tomography in anterior segment imaging. Acta Ophthalmol Scand 85: 427– 430. Sbeity Z, Dorairaj SK, Reddy S, Tello C, Liebmann JM & Ritch R (2008): Ultrasound biomicroscopy of zonular anatomy in clinically unilateral exfoliation syndrome. Acta Ophthalmol 86: 565– 568. Sneed SR & Weingeist TA (1990): Management of siderosis bulbi due to a retained iron-containing foreign body. Ophthalmology 97: 375– 379. Talamo JH, Topping TM, Maumenee AE & Green WR (1985): Ultrastructural studies of cornea, iris and lens in a case of siderosis bulbi. Ophthalmology 92: 1675– 1680. Citing Literature Volume88, Issue1February 2010Pages e1-e2 FiguresReferencesRelatedInformation