Perg/vep

PERG/VEP

PERG and VEP are two kinds of noninvasive electrical tests that measure how the visual system is working. PERG, short for pattern electroretinogram, records electrical signals generated by cells in the retina when a patterned image, like a checkerboard, is shown. VEP, or visual evoked potential, records the electrical response that reaches the visual cortex in the brain after a visual stimulus. Together, these tests tell doctors whether the retina and the nerve pathways to the brain are sending and processing visual information correctly. They are useful because they provide objective measurements of function even when a person cannot describe their vision well or when routine eye exams are normal. Technically, electrodes are placed on the skin or near the eyes while the person looks at specific visual patterns; the equipment then captures tiny voltage changes over time. Clinicians use these results to diagnose and monitor conditions such as optic nerve damage, inflammatory diseases, and some hereditary eye disorders. The tests are generally safe and quick, but their results can be affected by factors like poor focus, eye media clouding, or patient movement. In research and clinical practice, PERG and VEP help track disease progression and responses to treatment because they measure the function of the visual pathway directly.