Various SD-OCT features of focal choroidal excavations

To describe the clinical and spectral domain optical coherence tomography (OCT) features of two cases of focal choroidal excavation (FCE) and to review relevant literature to increase awareness and understanding of this rare condition.

Spectral domain OCT, enhanced depth imaging, and fundus autofluorescence (short wavelength and near infrared) were used to study two cases of FCE. Both patients were asymptomatic and maintained good vision at 6 months follow-up despite one case showing progression from a conforming- to a nonconforming-type FCE. At both lesion sites, the sclerochoroidal junction was unaltered, and the overlying retinal layers (retinal nerve fiber layer to outer plexiform layer) also remained intact. Enhanced depth imaging revealed an absence or compression of outer choroidal layers beneath the excavation and the presence of abnormally large choroidal vessels adjacent to the excavation. The near-infrared autofluorescence showed improved ability to highlight the FCE lesion compared with traditional short-wavelength autofluorescence.

Focal choroidal excavation is a rare, often asymptomatic macular condition. It appears on funduscopic examination as retinal pigment epithelial abnormalities, but its true structure is revealed with OCT. Certain spectral domain OCT imaging modalities, such as enhanced depth imaging and short and near-infrared autofluorescence, are helpful to monitor these lesions and to better understand its pathophysiology as it relates to choroidal vascular abnormalities.