Intraocular iron injection induces oxidative stress followed by elements of geographic atrophy and sympathetic ophthalmia.

Iron has been implicated in the pathogenesis of age-related retinal diseases, including age-related macular degeneration (AMD). Previous work showed that intravitreal (IVT) injection of iron induces acute photoreceptor death, lipid peroxidation, and autofluorescence (AF). Herein, we extend this work, finding surprising chronic features of the model: geographic atrophy and sympathetic ophthalmia. We provide new mechanistic insights derived from focal AF in the photoreceptors, quantification of bisretinoids, and localization of carboxyethyl pyrrole, an oxidized adduct of docosahexaenoic acid associated with AMD. In mice given IVT ferric ammonium citrate (FAC), RPE died in patches that slowly expanded at their borders, like human geographic atrophy. There was green AF in the photoreceptor ellipsoid, a mitochondria-rich region, 4 h after injection, followed later by gold AF in rod outer segments, RPE and subretinal myeloid cells. The green AF signature is consistent with flavin adenine dinucleotide, while measured increases in the bisretinoid all-trans-retinal dimer are consistent with the gold AF. FAC induced formation carboxyethyl pyrrole accumulation first in photoreceptors, then in RPE and myeloid cells. Quantitative PCR on neural retina and RPE indicated antioxidant upregulation and inflammation. Unexpectedly, reminiscent of sympathetic ophthalmia, autofluorescent myeloid cells containing abundant iron infiltrated the saline-injected fellow eyes only if the contralateral eye had received IVT FAC. These findings provide mechanistic insights into the potential toxicity caused by AMD-associated retinal iron accumulation. The mouse model will be useful for testing antioxidants, iron chelators, ferroptosis inhibitors, anti-inflammatory medications, and choroidal neovascularization inhibitors.

Choroidal Structural Changes in Sympathetic Ophthalmia on Swept-Source Optical Coherence Tomography.

Purpose: To analyze choroidal angioarchitecture in sympathetic ophthalmia (SO) using swept-source optical coherence tomography (SS-OCT) images.Methods: Case-control study of six patients with SO. Qualitative changes and quantitative parameters, including choroidal thickness (CT) and choroidal vascularity index (CVI), were analyzed.Results: Qualitative findings in the acute phase of SO on SS-OCT included retinal serous detachment with hyperreflective septa, choroidal folds, alterations in angioarchitecture with loss of vascular lacunae, and Dalen-Fuchs nodules. There was significantly higher CT in SO (284.05 ± 24.12 µm) compared to healthy controls (229.57 ± 46.67 µm, p = 0.04) and also increased CVI in SO (62.06 ± 2.07% vs 56.79 ± 3.15%, p = 0.006).Conclusions: CVI was significantly increased in SO, representing a novel noninvasive biomarker of disease activity. SS-OCT provides a useful qualitative and quantitative parameter, which can be potentially explored in the diagnosis and monitoring of patients with SO.

NOVEL OPTICAL COHERENCE TOMOGRAPHY FINDINGS OF A CASE OF SYMPATHETIC OPHTHALMIA AFTER 23-GAUGE VITRECTOMY.

PURPOSE: Sympathetic ophthalmia (SO) is a rare panuveitis after trauma to one eye. We present a case of SO after 23-gauge transconjunctival vitrectomy, including optical coherence tomography evidence of response to treatment. To our knowledge, this is the first SO case report to include spectral domain optical coherence tomography images of Dalen-Fuchs nodules. METHODS: Observational case report of a case of SO after two pars plana vitrectomies in the fellow eye. RESULTS: A 67-year-old woman who had an operation for her pseudophakic left eye for a macula-off retinal detachment. She had two surgeries and later on had a total retinal detachment with vision of no perception of light. Eighteen months later, she presented back with a panuveitis with vitritis in her other eye and a visual acuity of 6/18. Dalen-Fuchs denoting SO was found. Treatment was commenced, and multimodal imaging was performed. CONCLUSION: Sympathetic ophthalmia is a known complication after vitrectomy. Optical coherence tomography can be invaluable in monitoring diagnosis and progression of Dalen-Fuchs nodules.

[Sympathetic ophthalmia following repeated pars plana vitrectomy : Clinical findings and spectral domain OCT follow-up]. / Sympathische Ophthalmie nach zweimaliger Pars-plana-Vitrektomie : Klinische Befunde und Spectralis-OCT-Verlauf.

Sympathetic ophthalmia is a rare form of bilateral granulomatous panuveitis, occurring after penetrating trauma. Hitherto, sympathetic ophthalmia after vitrectomy has only occasionally been described in the literature. This case report presents a female patient with sympathetic ophthalmia after repeated pars plana vitrectomy on the basis of clinical findings and follow-up with fluorescein angiography, spectral domain OCT, and histopathology.

Multimodal Imaging in Sympathetic Ophthalmia.

PURPOSE: To show the current status of multimodal imaging and its role in supporting an early diagnosis of sympathetic ophthalmia. METHODS: The diagnosis is mainly clinical supported with ancillary investigations; mainly fluorescein angiography and others, including indocyanine angiography optical coherence tomography (OCT), OCT enhanced depth imaging, autofluorescence imaging, and ultrasonography. RESULTS: Various imaging modalities such as OCT, autofluorescence imaging and angiography are critical in the diagnosis and management of sympathetic ophthalmia. The clinician must make adequate use of such ancillary investigations in the management of the patients. CONCLUSIONS: Sympathetic ophthalmia is a rare, bilateral inflammation of the uveal tract following penetrating trauma or surgery in one eye. The intraocular inflammation requires a prompt diagnosis so that the treatment can be initiated as early as possible.

[Fluorescein angiographic picture of sympathetic ophthalmia (author's transl)]. / Fluoreszenzangiographie der sympathischen Ophthalmie

The fluorescein angiographic picture of sympathetic ophthalmia is described in an instructive case, which first started at the posterior pole. In the acute phase there was a picture of an exudative process with multiple subretinal enlarging hyperfluorecent spots and some dye-pooling. The retinal vasculature was unaffected. In the healing phase a transitory involvement of the optic nerve head was observed. The cicatricial phase was characterized by a coarsening of the pigment pattern of the fundus. In addition to fluorescein angiography the degree of transitory hyperopia was an excellent indicator of the activity of the disease process.