Sir,

Dengue fever is a disease caused by an arbovirus transmitted by the Aedes aegypti and Aedes albopictus mosquito, endemic to Southeast Asia and Southeast Africa,1 as well as Brazil, all of which are tropical regions.

Dengue fever, especially the classic variety, rarely affects the eye, but when it does, the consequences maybe severe. In 1929, Anargyros2 described bilateral retrobulbar neuritis in a patient with dengue fever.

The purpose of this report is to describe a case of bilateral stellar neuroretinitis in a patient diagnosed with classic dengue fever during an epidemic in Natal, Northeast-Brazil, in 2003, as yet unreported in the literature.

Case report

A Brazilian male patient aged 42 years from Natal was referred by an infectologist for assessment of low visual acuity in both eyes for the past 4 days. The patient had been experiencing asthenia, headaches, back pain, retro-orbital pain, skin rash and fever for 12 days and had been clinically diagnosed with dengue fever. Ophthalmological examination revealed best correct visual acuity: right eye – 20/50, left eye – 20/30; Applanation tonometry: 15 mmHg in both eyes (OU); slit-lamp examination: anterior segment was normal, vitreitis (+/++++); and using Volk 78D lens, bilateral papillitis was observed with areas of serous detachment in the posterior pole and in the vascular arcades (Figure 1). Automated perimetry (Humprey) showed an increased blind spot in both eyes and islands of sensitivity loss in the upper nasal and lower temporal regions of the right eye. Nuclear magnetic resonance of the cranium and the orbits were normal. The diagnosis of dengue fever was confirmed with positive serology (IgM antibodies). The patient remained under clinical and ophthalmological observation and was treated with analgesics. His hematimetric indices were kept under control. After a 2-month follow-up, the clinical picture and the neuroretinitis resolved spontaneously, with improved visual acuity (20/20 in OU) (Figure 2) and disappearance of perimetric alterations.

Figure 1
figure 1

Bilateral optic disc swelling with hemorrages and macular star.

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Figure 2
figure 2

Bilateral resolution of the optic disc swelling with minimal hard exsudates.

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Discussion

Sudden low visual acuity syndrome associated to optic disc oedema and macular star exudates is denominated neuroretinitis.3 Practically all neuroretinitis cases are of infectious origin, with Bartonella the main agent involved, causing cat scratch disease in two-thirds of the cases.3, 4 The differential diagnosis reported in the literature is performed with various infectious diseases, such as toxoplasmosis, leptospirosis, mumps, herpes simplex virus, salmonella, tuberculosis, Lyme disease and syphilis.4 Our report has added another rare diagnostic possibility when neuroretinitis appears in an individual with symptoms of viral infection in a dengue-endemic region.