Dengue fever may result in permanent retinal macular damage

By C. Vidya Shankar MD

NEW YORK (Reuters Health) - Visual loss due to macular injury following dengue fever may be more common than previously thought, according to results of a small study.

"We reported acute macular neuroretinopathy post dengue fever for the first time," lead author Dr. Fen Weng, from the Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China, told Reuters Health by email.

"Whilst maculopathy changes are reversible, neuroretinopathy can result in permanent central or paracentral scotomas," Dr. Weng pointed out.

The study included nine patients referred with dengue-associated maculopathy during the outbreak in China from August to September 2014. Five patients (55.6%) progressed to acute macular neuroretinopathy, four with bilateral involvement, the researchers reported online August 13 in JAMA Ophthalmology.

Five of the nine patients had persistent scotoma or visual blind spots attributed to acute macular neuroretinopathy (AMN) involving the inner photosensitive layer of the macula.

They confirmed dengue fever by polymerase chain reaction or serology. Early symptoms of maculopathy included blurring of vision, visual field floaters, near vision deficits, alteration in shape, and size of objects.

Fundoscopy and fluorescein angiography abnormalities included foveolitis, macular edema, microaneurysms, and hemorrhage. The ocular symptoms manifested three to seven days after onset of systemic illness, they noted.

In addition to signs of maculopathy, AMN was characterized by central or paracentral scotomas. Diagnosis was confirmed by hyporeflective lesions on infrared reflectance imaging and hyperreflection in the photoreceptor layer of the retina on spectral domain optical coherence tomography.

One patient was prescribed oral steroids for papilledema but did not respond, while the rest were managed conservatively. During the six-month follow up, the researchers noted complete resolution of maculopathy and partial visual improvement, but scotomas persisted in all their patients.

"The cause of their persistent scotomas could have been related to the irreversible thinning of the outer nuclear layer and incomplete restoration of the interdigitation zone," the researchers postulated.

They were unable to comment on the overall prevalence of maculopathy in dengue fever, because they only managed patients referred with severe eye disease. A previous study had noted maculopathy in 10% of patients hospitalized for dengue fever, Dr. Weng pointed out.

"There is no established treatment for dengue maculopathy," Dr. Weng emphasized. Neuroretinopathy "has a poor prognosis for patients with persistent central/paracentral scotomas," he concluded.

The National Natural Science Foundation of China and the Fundamental Research Funds of State Key Laboratory of Ophthalmology supported this research. The authors reported no disclosures.

SOURCE: http://bit.ly/1HVYXDw

JAMA Ophthalmol 2015.

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