This 55YO female has a history of type 2 diabetes and moderate nonproliferative diabetic retinopathy. An incidental finding shows bear-track lesions (congenital grouped hypertrophy of the RPE) superonasally in her left eye. These lesions hypo-autofluoresce.
Learning Points:
Group-type congenital pigmented nevi of the RPE (bear tracks) is a relatively rare congenital condition characterized by well-demarcated, flat, hyperpigmented, variably sized RPE lesions resembling bear tracks.
Histopathologically, these lesions are similar to congenital hypertrophy of the RPE (CHRPE), with increased numbers of pigment granules in normal-sized RPE cells. These lesions are benign and cause no visual symptoms.
The major fluorophore with fundus autofluorescence (FAF) is lipofuscin, which is intraliposomal RPE material generated as byproducts of outer segment metabolism.
The outer retina overlying these bear track lesions shows varying degrees of atrophy. This leads to less lipofuscin production with hypo-FAF.
