In vivo Confocal Microscopy in Differentiating Ipilimumab-Induced Anterior Uveitis from Metastatic Uveal Melanoma

This report aims to describe the facilitating role of in vivo confocal microscopy in differentiating inflammatory cells from a metastatic process in a patient with uveal melanoma and multiple systemic metastases who developed anterior uveitis while under ipilimumab treatment. A 43-year-old woman developed systemic metastases 11 months after treatment of amelanotic choroidal melanoma in her right eye with 30 Gy fractionated stereotactic radiotherapy. She first received temozolomide and then 4 cycles of ipilimumab 3 mg/kg/day. After the third cycle, severe anterior uveitis with coarse pigment clumps on the lens was seen in the left eye. Her left visual acuity declined from 20/20 to 20/80. Confocal microscopy revealed globular keratic precipitates with hyperreflective inclusions and endothelial blebs all suggestive of granulomatous uveitis. The uveitic reaction subsided after a 3-week course of topical corticosteroids, and her visual acuity was 20/20 again. Although uveal melanoma metastatic to the intraocular structures of the fellow eye is exceedingly rare and metastasis masquerading uveitis without any identifiable uveal lesion is even more unusual, it was still mandatory to rule out this distant possibility in our particular patient who already had widespread systemic metastases. Confocal microscopy was a useful complementary tool by identifying the inflammatory features of the keratic precipitates.