This 22YO healthy female presented with a year or two of mildly symptomatic problems with distance vision. Vision was 20/25 OD and 20/30 OS. There was no family history of eye disease, and her hearing was normal.
Optos color imaging shows bilaterally symmetrical doughnut-shaped rings of subtle pigmentary changes around each macular center. Fundus autofluorescence (FAF) shows these rings to be hyper-FAF. Swept-source OCT shows outer retinal atrophy. 30-2 visual fields are constricted.
Learning Points:
FAF visualizes fluorophores, endogenous compounds that spontaneously fluoresce without the need for an external dye. The main fundus fluorophore is lipofuscin, which resides within the RPE lysosomes. The photoreceptor outer segments absorb some of the autofluorescent excitatory light, and thus normally diminish the FAF signal.
In RP, loss of the outer segments unmasks this signal, leading to increased FAF. Many patients with RP will show a hyper-FAF ring between clinically normal and abnormal retina, which likely represents retina ‘at risk’, showing the junction of a functional and dysfunctional retina.
