An asymptomatic 26-year-old previously healthy white male was referred to us following a routine optometrist visit. Visual acuity was 6/6 in both eyes, with no sign of anterior segment inflammation, but with the presence of a single, inactive, yellow choroidal lesion, 0.75 mm in diameter, located inferior to the left optic disc (fig. 1).
Time domain OCT of the lesion showed thinning and compression of the overlying choroidal vasculature with an apparently normal retina above it. Spectral domain OCT with enhanced depth imaging (fig. 2) helped locate the lesion on the choroid and sclera, under the attenuated choroidal vasculature, without evidence of disruption of the outer or inner retinal layers and the retinal pigment epithelium (RPE). FAF (fig. 3) revealed a hyperautofluorescent area corresponding with the mass.
Ultrasound B-scans failed to show any elevated lesion or thickening of the 'coats' since conventional B-scans cannot separate choroidal from scleral layers. Also, there was no evidence of the sub-Tenon fluid and the T-sign was negative.
The common systemic causes of a choroidal granuloma were tested for sarcoidosis (serum angiotensin-converting enzyme and calcium) and tuberculosis (QuantiFERON Gold), and both were negative. Other less common causes of SIC such as Toxocara, Brucella and Wegener's disease were excluded either by anamnesis and/or additional tests. Also, inflammatory markers (erythrocyte sedimentation rate and C-reactive protein) were within normal limits and the chest X-ray showed no abnormalities. Taking the funduscopic appearance and the image characteristics on the OCT and FAF into account, the diagnosis of SIC was made.