Optical coherence tomography of choroidal nevus in 120 patients

Objective: To describe the optical coherence tomography (OCT) findings of choroidal nevi. Methods: Retrospective, single-center case series of 120 eyes of 120 consecutive patients with choroidal nevi who were evaluated by OCT. Diagnostic imaging was performed with a Zeiss StratusOCT Model 3000 (Carl Zeiss Ophthalmic Systems, Dublin, CA) using scan acquisition protocols of 6 radial lines and retinal thickness analysis overlying the nevus. Results: The mean patient age was 59 years (median, 60 years; range, 14-87 years). The choroidal nevus was a mean of 5.2 mm in basal dimension and 1.7 mm in thickness and was located a mean of 2.7 mm from the optic disk and 2.5 mm from the foveola. Related retinal findings by ophthalmoscopic evaluation included overlying retina edema (3%), subretinal fluid (16%), retinal thinning (0%), drusen (58%), and retinal pigment epithelium (RPE) detachment (2%). In comparison, related retinal findings at the site of the nevus by OCT included overlying retina edema (15%), subretinal fluid (26%), retinal thinning (22%), drusen (41%), and RPE detachment (112%). Furthermore, OCT permitted classification of the overlying retinal edema as focal cystoid (3%), diffuse cystoid (8%), coalescent cystoid (3%), and noncystoid edema (11 %). By OCT, the overlying retina was normal thickness (32%), thinned (22%), or thickened (45%), and photoreceptor loss or attenuation was noted in 51 % of cases. Specific OCT findings of the choroidal nevus were limited to its anterior surface with minimal penetration into the mass. These findings included increased thickness of the RPE/choriocapillaris layer (68%) and optical qualities within the anterior portion of the nevus of hyporeflectivity (62%), isoreflectivity (29%), and hyperreflectivity (9%). Hyporeflectivity was observed in 68% of pigmented nevi and 18% of nonpigmented nevi. When comparing OCT with clinical examination, OCT was more sensitive in the detection of related retinal edema, subretinal fluid, retinal thinning, photoreceptor attenuation, and RPE detachment. Conclusions: OCT is a useful diagnostic modality for imaging the retina overlying a choroidal nevus. Numerous overlying changes such as subretinal fluid, retinal edema, retinal thinning, and photoreceptor attenuation are visible by OCT.