This 63YO male presented with 1 month of bilateral decreased vision following dengue fever, with positive Dengue NS1 antigen during the acute illness. Vision was 20/200 OD and counting fingers OS.
Pseudocolor SLO imaging shows extensive peripapillary cotton wool spots, retinal whitening, and significant macular edema. The fundus detail is partially obscured by overlying vitreous debris from vitritis. OCT scanning neurosensory retinal detachment with subretinal hyperreflective material, intraretinal cystoid edema, and subretinal fluid involving the macula in both eyes, consistent with post-dengue inflammatory retinitis. A possible bacillary layer detachment is also noted in the left eye.
Topical steroids and a 9-week course of tapering oral steroids, as well as a 3-week course of oral doxycycline, were started. Four months later, vision improved to 20/20 OD and 20/30 OS. The patches of white inner retinal ischemia are fading, and some lipid flecks have precipitated out in the mid-retina.
Learning Points:
Epidemic (post-fever) retinitis is an infectious or para-infectious entity that develops in immunocompetent individuals 2-6 weeks following a bacterial, viral, or protozoal infection. Rickettsiosis is the most identified cause, though a large proportion of cases remain idiopathic despite serologic testing; dengue, chikungunya, West Nile, Zika, leptospirosis, typhoid, and Ebola have also been implicated. Patients present with sudden painless vision loss. Fundus findings include unilateral or bilateral unifocal or multifocal patches of retinitis with possible nerve involvement, neuroretinitis with macular star, serous macular detachment, cystoid macular edema, and vasculitis or frosted branch angiitis.
Management is stratified by etiology and lacks controlled data: bacterial causes are treated with systemic antibiotics with or without corticosteroids, viral causes with corticosteroids alone, and many authors advocate observation, as the disease often resolves on its own. Corticosteroids should not be used as sole therapy while infectious causes (including TB, syphilis, and toxoplasmosis) remain in the differential. See Mahendradas et al (Indian J Ophthalmol 2020;68:1775-1786) for an excellent post-fever retinitis review.
