Clinical features and differential diagnosis of acute idiopathic blind spot enlargement syndrome.

Purpose: To study the clinical manifestations and the diagnostic and differential diagnostic characteristics of acute idiopathic blind spot enlargement syndrome (AIBSES).

Methods: Six patients diagnosed with AIBSES underwent complete eye examinations including fundus photography, fundus fluorescein angiography(FFA), indocyanine green angiography (ICGA), optical coherence tomography (OCT), electroretinogram (ERG), and visual field examinations.

Results: All patients had enlarged blind spots of variable sizes and densities. Three eyes had mild swelling of the optic disc and one eye had peripapillary scarring that corresponded to the permanent field defect. Two patients who underwent FFA had fluorescein leakage of blood vessels around the optic disc and ICGA highlighted diffuse, small hypofluorescent spots scattering throughout the posterior pole. OCT showed that the inner and outer segment (IS/OS) line were absent in five patients and the middle cone outer segment tip line was absent in the nasal macular area in one eye.

Conclusion: AIBSES is a rare outer retinopathy. Visual field examination and OCT are the most important means of detection. ICGA and FAF can determine the range of lesions earlier, and the progress of the disease should be taken into account when making a diagnosis.