This 69-year-old lady presented to her optometrist with a sudden onset of a teardrop-shaped, paracentral scotoma superonasal to fixation in the vision from her left eye.
Macular OCT scan of the left eye shows a hyperreflective plaque in the outer part of the OCT in an area corresponding to the location of the patient’s scotoma (i.e. inferotemporal to the centre of the fovea). There is associated disruption of the ellipsoid zone (photoreceptor layer).
The lesion was not visible on fundoscopy, but the above infrared image shows a teardrop-shaped area of decreased signal inferotemporal to the centre of the fovea, which corresponds with the OCT changes and the patient’s symptoms.
Two months later the patient reported some spontaneous improvement in symptoms with the scotoma being much less obvious and no longer intrusive.
Acute macular neuroretinopathy is a relatively rare condition originally defined by the presence of intraretinal, reddish-brown, wedge-shaped lesions, the apices of which tend to point toward the fovea. Acute onset of paracentral scotomas corresponding to the clinically evident lesions is both common and characteristic. Although the pathogenesis of acute macular neuroretinopathy is complex, recent research suggests a microvascular aetiology with substances such as caffeine and ephedrine identified as possible associations.
There is no treatment for this condition. Some scotomas partially resolve, some do not resolve at all. However, it is very unlikely that a patient will experience significant loss in an affected eye. The visual prognosis is usually good.