We report a case of optic neuritis after dengue viral infection, a phenomenon not previously reported.
A 20-year-old man was referred to Ramathibodi Hospital in February 2001 with a history of bilateral visual loss. Seven days before, the patient had presented to another hospital with a 3-day history of high fever and vomiting. Physical examination revealed high temperature, minimal cervical lymphadenopathy, hepatomegaly, and a positive tourniquet test. Laboratory examination revealed thrombocytopenia (platelet count 60,000/mm3). Viral infection with dengue hemorrhagic fever was suspected as the likely diagnosis. Two days later, the fever started to subside and the platelet count decreased to 30,000/mm3. He was treated conservatively with intravenous fluids, electrolytes, and glucose. No clinical evidence of hypovolemic shock occurred in this patient. Two days after the fever had subsided, the patient experienced gradual loss of vision in his right and OD. Physical examination at our hospital revealed a well-developed man without signs of acute distress. Temperature, blood pressure, and pulse rate were normal. The liver was palpable and a positive convalescent rash on extremities was found. Visual acuity was counting fingers OU. Pupils measured 3 mm in dim illumination and reacted normally to light. Extraocular motility was normal without pain. Ophthalmoscopy revealed mild bilateral optic disc hyperemia with a flame-shaped hemorrhage at the fovea OD. Goldmann visual field tests demonstrated bilateral cecocentral scotomas (Fig. 1). Retinal fluorescein angiography demonstrated no disc leakage.
Laboratory results included hemoglobin 15.3 g/dL, white blood count 6,310/mm3 (30% polymorphonuclear cells, 52% lymphocytes, 14% monocytes, and 2% atypical lymphocytes), platelets 238,000/mm3, and elevated liver enzymes (glutamic-oxaloacetic transaminase 402 U/L, glutamic-pyruvic transaminase 529 U/L, γ-glutamyltransferase 280 U/L). Coagulation studies were normal. Serologic analyses for syphilis (venereal disease research laboratory and fluorescent treponemal antibody absorption test) were negative. Lumbar puncture revealed clear and colorless cerebrospinal fluid with normal glucose, protein, cell count, and differential. A brain and orbit magnetic resonance imaging study demonstrated enhancement of both optic nerves.
The diagnosis of dengue infection was confirmed after IgM and IgG antibodies for dengue virus serotype I were detected in the serum.
The patient was treated with intravenous methyl-prednisolone 250 mg four times per day for 3 days, followed by prednisolone 60 mg/d slowly tapered over 4 weeks. Visual acuity improved gradually, being 20/200 OD and 10/200 OS after 1 month, and returning to 20/20 OU after 8 months. Over 18 months of follow-up, he has had no further ocular or neurologic symptoms. Visual acuity after 26 months remains 20/20 OU and color vision testing with Ishihara plates is normal.
Dengue or dengue hemorrhagic fever is a mosquitotransmitted viral disease that is endemic mainly in Southeast Asia and the Western Pacific region. The ocular manifestations include photophobia, retrobulbar pain, conjunctival congestion, subconjunctival hemorrhage, retinal vessel engorgement, and accommodative weakness (1,2). Retinal hemorrhages and maculopathy are rare but have been reported to cause visual loss (3). Optic nerve ischemia can occur in survivors of dengue hemorrhagic fever after severe hypotension and circulatory failure (4). To our knowledge, this is the first reported case of bilateral optic neuritis associated with a dengue viral infection. As in many parainfectious cases with optic neuritis, profound loss of visual function occurred with nearly complete recovery.
Pisit Preechawat, MD
Anuchit Poonyathalang, MD
Department of Ophthalmology; Ramathibodi Hospital; Mahidol University; Bangkok, Thailand; E-mail: email@example.com
1. Beck RW. Optic neuritis. In: Miller NR, Newman NJ, eds. Walsh & Hoyt's Clinical Neuro-Ophthalmology, 5th
ed. Baltimore: Williams & Wilkins, 1999:628-9.
2. Gill WD. Ocular symptoms in dengue based on analysis of 1241 cases. Arch Ophthalmol.
3. Haritoglou C, Scholz F, Bialasiewicz A, et al. Ocular manifestation in dengue fever. Ophthalmologe.
4. Hendarto SK, Hadinegoro SR. Dengue encephalopathy. Acta Paediatr Jpn.