RESUMEN
PURPOSE: To report chorioretinal vasoconstriction as a potential pathogenic mechanism in acute macular neuroretinopathy (AMNR). To describe a time lag between the onset of functional deficits and that of fundoscopically visible lesions and illustrate the superior value of infrared (IR) compared to red-free or white light imaging in AMNR. METHODS: Two young female patients (30 and 19 years old) with AMNR are described. Both underwent detailed clinical examination with additional imaging using IR, blue, and red-free light. Functional evaluation with pattern and multifocal electroretinography, Goldmann manual, and automated Humphrey visual fields (VFs) was also performed. RESULTS: The first patient was diagnosed with AMNR after a caesarian section during and after which she received treatment with vasoconstrictive drugs. She was followed up for 28 months, after which time she still suffered from bilateral U-shaped paracentral scotomata associated with macular lesions. The second patient complained of central scotomata prior to the onset of any visible fundoscopic lesions, following a bout of flu. VFs confirmed a central scotoma and pattern electroretinography was consistent with loss of macular function. Bilateral petaloid lesions became visible after 3 days when function began to improve. In both patients IR imaging was superior to standard red-free and white light in identifying macular lesions. CONCLUSIONS: Vasoconstriction in the chorioretina may be pathogenic in AMNR. Functional complaints precede fundus lesions in AMNR. And, IR light is superior to red-free or white light imaging in detecting typical fundus lesions in AMNR both early and late in the course of the disease.