Choroidal atrophy most frequently results in a decrease in acuity and (in the diffuse form) poor night vision, starting at age 40 to 50. Generally, the amplitude of the ERG parallels the clinically apparent fundus involvement. If ERG amplitudes are lower than expected, cone dystrophy should be suspected.

Patients with gyrate atrophy generally present between 20 and 30 years of age with poor night vision. The ERG cone and rod amplitudes are markedly reduced or completely absent. Gyrate atrophy is one of the few progressive night-blinding disorders in which a metabolic defect has been implicated and for which therapeutic trials with a low protein diet are under investigation.