Leaning tower of the retina: A decade-old encapsulated intraocular foreign body
Year: 2026
Type: article
Study design: Case Report
Abstract: Purpose: To report a rare case of dense fibrotic encapsulation surrounding a ferrous intraocular foreign body (IOFB) retained for over a decade, with minimal overt clinical signs of siderosis but retinal dysfunction detected by full-field electroretinography (ERG). Methods: A 31-year-old man presented with visual acuity of hand motion 10 years after metallic ocular trauma. Slit-lamp examination and B-scan ultrasonography revealed a luxated hypermature lens and a unique, vertical "leaning tower"-like fibrotic mass adjacent to the lens. Vitrectomy was performed to remove the lens and the encapsulated mass. The content of the fibrotic capsule was confirmed to be oxidized iron fragments. Results: Despite the long-term retention of ferrous material, the patient exhibited no overt clinical signs of siderosis bulbi, such as iris heterochromia or retinal degeneration. Postoperatively, visual acuity improved to 20/100, and optical coherence tomography showed preserved outer retinal layers and no macular edema. However, full-field ERG demonstrated markedly reduced flash a- and b-wave amplitudes and a severely reduced 30-Hz flicker response in the affected eye. Conclusions and importance: Dense fibrotic encapsulation may mitigate overt clinical siderosis in eyes with long-standing ferrous IOFBs, but it does not necessarily prevent retinal dysfunction. Full-field ERG may be important for functional assessment even when clinical signs of siderosis are minimal and retinal anatomy appears relatively preserved.
Author: Ryuya Hashimoto
Language: English
Subfield: Ophthalmology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $1,590
OpenAlex ID: W7223671626