Anti-interleukin-6 receptor therapy with tocilizumab for refractory pseudophakic cystoid macular edema

PURPOSE: To describe the clinical course of a patient with refractory pseudophakic cystoid macular edema treated with interleukin-6 receptor antagonist tocilizumab. OBSERVATIONS: An 80-year-old Caucasian man with past ocular history significant for glaucoma (right eye) and iritis presented with cystoid macular edema (CME) in the right eye (OD). His ocular surgery history was significant for cataract extraction with posterior chamber intraocular lenses in 1999 and YAG laser capsulotomy in 2014 in both eyes (OU). His medications at time of presentation included latanoprost and dorzolamide-timolol in OD for glaucoma, as well as prednisolone in OD for iritis. Upon examination, his visual acuity was 20/250 in OD and 20/20 in the left eye (OS). Intraocular pressure was 20 mmHg in OD and 10 mmHg in OS. Slit-lamp examination revealed no cells or flare in OU. Dilated fundus exam showed CME and a cup-to-disk ratio of 0.9 in OD and normal findings in OS. Initial spectral domain optical coherence tomography (SD-OCT) demonstrated intraretinal fluid in both outer and inner layers as well as mild subretinal fluid with an intact ellipsoid zone in OD. Fluorescein angiography revealed perifoveal leakage in OD. Laboratory evaluations, including infectious work-up, were unremarkable. While the patient's CME initially improved after initiation of therapy with topical prednisolone and oral acetazolamide, the CME later recurred after systemic acetazolamide was stopped due to intolerable side effects. Despite multiple therapeutic approaches, including topical and systemic corticosteroids (both oral and intravenous) and topical interferon α2b over the course of more than one year, the patient's visual acuity continued to worsen with increasing intra- and subretinal fluid in the macula. Due to the refractory CME, the patient was started on monthly infusions of anti-interleukin (IL)-6 receptor tocilizumab (8 mg/kg) with three days of methylprednisolone infusions (500 mg/day). After nine cycles of treatment, SD-OCT demonstrated restoration of normal foveal contour with complete resolution of CME. CONCLUSIONS AND IMPORTANCE: IL-6 inhibition with tocilizumab may be a safe and effective treatment for refractory CME. Further studies are needed to elucidate the nature and extent of therapeutic IL-6 inhibition in CME.