Role of inflammation in a rat model of radiation retinopathy.

Radiation retinopathy (RR) is a major side effect of ocular tumor treatment by plaque brachytherapy or proton beam therapy. RR manifests as delayed and progressive microvasculopathy, ischemia and macular edema, ultimately leading to vision loss, neovascular glaucoma, and, in extreme cases, secondary enucleation. Intravitreal anti-VEGF agents, steroids and laser photocoagulation have limited effects on RR. The role of retinal inflammation and its contribution to the microvascular damage occurring in RR remain incompletely understood. To explore cellular and vascular events after irradiation, we analyzed their time course at 1 week, 1 month and 6 months after rat eyes received 45 Gy X-beam photons. Müller glial cells, astrocytes and microglia were rapidly activated, and these markers of retinal inflammation persisted for 6 months after irradiation. This was accompanied by early cell death in the outer retina, which persisted at later time points, leading to retinal thinning. A delayed loss of small retinal capillaries and retinal hypoxia were observed after 6 months, indicating inner blood‒retinal barrier (BRB) alteration but without cell death in the inner retina. Moreover, activated microglial cells invaded the entire retina and surrounded retinal vessels, suggesting the role of inflammation in vascular alteration and in retinal cell death. Radiation also triggered early and persistent invasion of the retinal pigment epithelium by microglia and macrophages, contributing to outer BRB disruption. This study highlights the role of progressive and long-lasting inflammatory mechanisms in RR development and demonstrates the relevance of this rat model to investigate human pathology.

Indocyanine Green Angiography Features in Acute Syphilitic Posterior Placoid Chorioretinitis.

PURPOSE: Acute syphilitic posterior placoid chorioretinitis (ASPPC) is a rare clinical manifestation of ocular syphilis. The cause of the placoid lesion is still up for debate but could be caused by an impaired choriocapillaris perfusion. However, less attention has been paid to the hypofluorescence of the plaque on late-phase indocyanine green angiography (ICGA). The aim of this study was to comprehensively analyze multimodal imaging findings in patients with ASPPC and to highlight the value of ICGA for the diagnosis of ASPPC. DESIGN: Retrospective observational case study. METHODS: The medical records of patients with uveitis who consulted our tertiary center between 2012 and December 2015 were reviewed. Patients who were diagnosed with uveitis related to syphilis infection with posterior placoid lesions seen on multimodal imaging were included. We compared the aspect of ASPPC on fundus color photography, blue autofluorescence, fluorescein angiography, optical coherence tomography, and early-, mid- and late-phase ICGA. RESULTS: Fifteen eyes of 12 patients were included in the study. Hypofluorescent plaques were seen on late-phase ICGA in all eyes, corresponding to the placoid lesions visible on blue autofluorescence, while the choriocapillaris filling was normal on fluorescein angiography and ICGA. Within the plaques, optical coherence tomography showed ellipsoid zone disruptions, outer retinal disruptions, and retinal pigment epithelium granulations. CONCLUSION: ASPPC could be caused by retinal pigment epithelium dysfunction secondary to an infectious or inflammatory disorder, characterized by a hypofluorescence visible only on late-phase ICGA, and resulting in photoreceptor disruptions. The RPE impairment was reversible after prompt antibiotic treatment.

In Vivo Confocal Microscopy of Prominent Conjunctival and Corneal Nerves in Multiple Endocrine Neoplasia Type 2B.

OBJECTIVE: To report a case of a patient affected by multiple endocrine neoplasia type 2B (MEN 2B) with imaging of conjunctival neuromas by in vivo confocal microscopy (IVCM). METHODS: Case report. RESULTS: A 48-year-old patient affected by MEN2B complained of progressive visual loss in his right eye and severe red, dry and itchy eyes. Best-corrected visual acuity was 20/63 OD and 20/25 OS. Slit lamp exam showed thickened and turned out lid margins, significant blepharitis, conjunctival injection, multiple presumed subconjunctival neuromas at the bulbar conjunctiva and at the limbus, marked prominence of corneal nerves, exposure keratopathy due to incomplete blinking and corneal hypoesthesia, subepithelial corneal neovascularization and scarring in the mid inferior part of both corneas and bilateral iris nodules. We performed IVCM on conjunctival neuromas, revealing large, thick bundles of nerves with disorganization, prominent loops, bifurcations and dilations measuring as much as 1 mm. The IVCM of corneal nerves demonstrated hypertrophic sub basal plexus. CONCLUSIONS: To date, this is the first report which documents conjunctival neuromas by confocal microscopy in MEN2B.