Progressive, bilateral, and symmetrical visual impairment |
Central or centrocecal scotoma |
Dyschromatopsia |
Loss of contrast sensitivity |
Signs
|
No relative afferent pupillary defect (RAPD) |
Normal or hyperaemic optic disc (early stages)—except for thiamine deficiency where it is swollen already at early stages |
Temporal, then diffuse optic disc pallor (late stage) |
Thinning of RNFL in papillomacular bundle (early stage) |
Thinning of RNFL involves of all the quadrants (late stage) |
Normal or near normal latency with significantly reduced amplitude of VEP |