Purpose: To describe the clinical course of bilateral acute idiopathic maculopathy (BAIM), and to analyze its pathophysiology.
Case: A 33-year-old Japanese woman presented with a sudden, severe, bilateral visual disturbance following a flu-like illness. She was examined by fluorescein angiography (FA), indocyanine green angiography (IA), scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT), and multifocal electroretinography (mfERG).
Observations: A diagnosis of BAIM was made in this patient based on typical ophthalmoscopic features, which included a pathognomonic yellowish-white foveal lesion. FA demonstrated a breakdown of the outer blood-retinal barrier, with the size and location corresponding to the white lesion, and IA disclosed a choroidal circulatory disturbance. SLO demonstrated that the deep retinal and choroidal layers were disorganized, and OCT showed retinal edema. Electrophysiological dysfunction was detected by mfERGs. After steroid therapy, the patient's visual acuity recovered to normal. The pooling of fluorescein dye and the OCT-determined retinal edema were resolved. However, the physiological dysfunction detected by mfERGs remained.
Conclusions: We conclude that the major abnormality in BAIM is an alteration of the retinal pigment epithelium causing severe edema.