Choroidal melanocytosis evaluation with enhanced depth imaging optical coherence tomography.

Objective: To assess eyes with unilateral choroidal melanocytosis using enhanced depth imaging (EDI) optical coherence tomography (OCT).

Methods: Retrospective, observational case series. Methods: Fifteen patients with unilateral choroidal melanocytosis. Methods: Each patient was evaluated with EDI-OCT, and comparison was made of involved versus uninvolved foveal retinal and choroidal layers. Methods: Enhanced depth imaging OCT features of choroidal melanocytosis.

Results: The mean patient age was 28 years (median, 23 years; range, 5-76 years). There were 9 male and 6 female patients. Best-corrected visual acuity ranged from 20/20 to 20/30. All patients had subfoveal involvement with choroidal melanocytosis. Associated features included dermal (n = 6), scleral (n = 9), iris (n = 3), and palate (n = 1) melanocytosis. Spectral domain EDI-OCT revealed normal inner retina (n = 15) and normal outer retina (n = 14). The only retinal abnormality was a defect in both the myoid zone and the ellipsoid junction (n = 1). The affected choroid showed smooth anterior contour (n = 15) and thinned or compressed choriocapillaris (n = 2), thinned (n = 3) or thickened (n = 3) medium vessels, and thinned large vessels (n = 2). The subfoveal choroid was a mean 23% thicker in the involved eye, with a mean thickness of 326.4 μm (median, 326 μm; range, 120-459 μm) compared with 264.4 μm (median, 260 μm; range, 94-462 μm) in the uninvolved eye (P = 0.15). The choroidal perivascular interstitial tissue was 51% thicker in the study eye, enwrapping and silhouetting the medium and large vessels (P = 0.01). The ratio between the perivascular stromal tissue and the subfoveal choroidal thickness was 66% in the study eye and 54% in the normal eye (P = 0.0001). Deep partial (n = 5) or complete (n = 2) tissue shadowing was noted.

Conclusions: Enhanced depth imaging OCT revealed that choroidal melanocytosis shows increased subfoveal choroidal thickness with an apparent increase in the choroidal perivascular stromal tissue and minimal effect on the overlying retina.