The central fovea
appears as an isolated, pigmented island, surrounded by an annulus of atrophied, depigmented retinal pigment epithelium, itself encompassed by a hyperpigmented region.
In this protocol, manual measurement of the outer retinal layer thickness (OLT) was performed at a point in the central fovea from internal limiting membrane (ILM) to the apex of retinal pigmented epithelium (RPE) by an ophtalmologist who was blinded to the primary diagnosis and drug consumption properties of the subjects.
Ophthalmoscopic examination may reveal granular pigmentary changes in the form of bull's-eye maculopathy with a circle of RPE atrophy surrounding the central fovea.
It is as if the peripheral afterimage is considerably retarded with respect to the central fovea
Within the central fovea
, the carotenoids are most concentrated within the photoreceptor axons of the Henle nerve fibre layer (31).