Choroidal Effusion Mimicking Uveal Melanoma: A Novel Presentation of Idiopathic Systemic Capillary Leak Syndrome.

BACKGROUND: Idiopathic systemic capillary leak syndrome (ISCLS, also known as Clarkson's disease) is a rare medical condition characterized by episodes of capillary endothelial cell dysfunction with leakage of fluid into the interstitial space resulting in severe hypotension, hemoconcentration, hypoalbuminemia, and generalized edema. Each episode can result in multiorgan failure due to systemic hypoperfusion. CASE PRESENTATION: We report a case of uveal effusion, mimicking uveal melanoma, associated with ISCLS following viral infection. A 74-year-old white male was evaluated in our ocular tumor clinic for a large intraocular mass in the right eye concerning for choroidal melanoma. We completed a review of the literature and list clinical recommendations for these cases. ISCLS, although rare, was a significant diagnostic consideration in this patient. Due to the high mortality rate of this condition, accurate diagnosis and prompt treatment was critical. We hypothesize that the mechanism of choroidal effusion development was due to reduced oncotic pressure from rapid decrease in serum albumin. Increased permeability of choroidal capillaries may be an additional mechanism leading to uveal effusion. CONCLUSION: With treatment, the patient had complete resolution of his choroidal effusion with no recurrence of his ISCLS. Further research should be considered on the role of viral infections in the pathogenesis of ISCLS.

Oral Selumetinib Does Not Negatively Impact Photoreceptor Survival in Murine Experimental Retinal Detachment.

Purpose: Mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling is neuroprotective in some retinal damage models but its role in neuronal survival during retinal detachment (RD) is unclear. In addition, serous RDs are a prevalent side effect of MEK inhibitors (MEKi), blocking MAPK/ERK signaling for treatment of certain cancers. We tested the hypothesis that MEKi treatment in experimental RD would increase photoreceptor death. Methods: The MEKi selumetinib was delivered daily to C57BL/6 mice at a clinically relevant dose (10 mg/mL) starting 1 day prior to creating RD with subretinal hyaluronic acid injection. Photoreceptor TUNEL and outer nuclear layer (ONL) thickness were analyzed. Phospho-ERK1/2 (pERK) distribution, glial fibrillary acidic protein (GFAP) accumulation, and Iba-1 (microglia/macrophages) were evaluated with immunofluorescence. Results: pERK accumulated in the Müller glia in detached retinas, but this was effectively blocked by selumetinib. Selumetinib did not induce serous RDs at day 1 and did not increase TUNEL positive photoreceptors or further decrease ONL thickness compared to controls. Retinal gliosis was not altered, but selumetinib did block the increase in intraretinal microglia/macrophage Iba-1 fluorescence intensity and acquisition of amoeboid morphology. Conclusions: MAPK/ERK is neuroprotective in some retinal damage models; in RD, selumetinib blocked Müller pERK accumulation and changed the retinal microglia/macrophage phenotype but did not alter photoreceptor survival. This is consistent with the relatively good visual acuity seen in patients developing transient retinal detachments on MEK inhibitor therapy. Compensation by other neuroprotective pathways in the retina during retinal detachment may occur in the presence of MEK inhibition.