Congenital hypertrophy of the retinal pigment epithelium

This lesion, which is also called ‘CHRPE' (pronounced 'chirpy’), is a flat birthmark at the back of the eye. It is a large, dark, black spot, typically with a few white spots and discrete edges, often surrounded by a white ‘halo’. Despite its striking appearance, it almost always entirely harmless and does not require any treatment. These lesions can give rise to adenoma or adenocarcinoma, but such an occurrence is extremely rare.



CHRPE lesion of the right eye showing deep pigmentation and discrete margins.


Many CRPE lesions tend to show a depigmented 'halo'.



Depigmented 'halo' around a CHRPE lesion


CHRPE lesions tend to show white, atrophic areas called 'lacunae', where the internal scleral surface is visible.



Atrophic 'lacuna' within a CHRPE lesion


In some lesions (i.e., 'polar bear spots'), the lacuna is very extensive.