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Updated: Jul 19, 2026
Multifocal Electroretinograms
Published on: December 4, 2011
Electrophysiological findings in patients with dengue-related maculopathy
Audrey Chia1, Chi D Luu, Ranjana Mathur
1Singapore National Eye Centre, Singapore. wla_chia@yahoo.com
Objective:
To assess visual function in patients with dengue maculopathy using electrophysiological tests.
Methods:
Fifteen consecutive patients with dengue fever who experienced vision loss between July 2004 and July 2005 were included in this review. Full-field electroretinograms (ERG), pattern ERGs, and multifocal ERGs were performed.
Results:
The most common electrophysiological finding (60%, 9/15) was a normal or mildly abnormal full-field ERG with reduced pattern ERG P50 amplitude and abnormal mfERG. Typically, multifocal ERG demonstrated a focal area of decreased macular response (especially between the fovea and optic nerve). Pattern ERG suggested normal optic nerve function in all but 1 case. Four patients had more severely reduced full-field ERG responses with reduced a-wave amplitude (suggestive of photoreceptor dysfunction), 3 of whom had an electronegative maximal response (suggestive of additional postreceptor dysfunction). Repeat multifocal ERG showed little change in 7 patients and incomplete resolution in 2 patients over 3 to 10 months.
Conclusion:
Retinal dysfunction associated with dengue maculopathy was localized mainly around the foveal region. It appeared to affect the outer and middle retina more severely with relative sparing of the inner retina. Retinal dysfunction may persist for several months. Longer follow-up is required to determine whether these changes are permanent.
Insights
Electrophysiological tests reveal that dengue maculopathy primarily affects the outer and middle retina, particularly around the fovea. Visual dysfunction may persist for months, with longer follow-up needed to assess permanence.
Area of Science:
- Ophthalmology
- Neuroscience
- Infectious Diseases
Background:
- Dengue maculopathy is a visual complication of dengue fever.
- Electrophysiological tests are crucial for assessing retinal function.
Observation:
- Fifteen patients with dengue maculopathy and vision loss underwent electroretinography (ERG).
- Tests included full-field ERG, pattern ERG, and multifocal ERG (mfERG).
Findings:
- Most patients showed normal/mildly abnormal full-field ERG but reduced pattern ERG P50 and abnormal mfERG.
- mfERG indicated focal macular dysfunction, primarily between the fovea and optic nerve.
- Some patients exhibited photoreceptor and post-receptor dysfunction, with persistent retinal changes over 3-10 months.
Implications:
- Dengue maculopathy causes dysfunction mainly in the foveal region, affecting outer and middle retinal layers.
- Inner retinal layers appear relatively spared.
- Retinal dysfunction can be long-lasting, necessitating further research into its permanent effects.
