Abstract
Background: Optic neuritis is an inflammation of the optic nerve. Inflammation may occur due to primary demyelination processes e.g. multiple sclerosis, or secondary due to other causes. Visual Evoked Potential (VEP) is an objective examination that can detect the optic nerve lesion. A characteristic finding of VEP in optic neuritis patient is prolongation of VEP latency that can last for several years. This study was conducted to determine the characteristics of VEP in optic neuritis patients at Sanglah General Hospital, Denpasar, Bali, Indonesia.
Methods: A descriptive cross-sectional study was performed, involving subjects with optic neuritis admitted to Neurology clinic at Sanglah General Hospital 2017-2019. All VEP recordings were interpreted by a certified neurophysiology consultant. The collected data subsequently processed and analyzed statistically.
Results: A total of 42 subjects with optic neuritis were admitted, by which 17 of them were males and 25 females, respectively, with average age of 38.4 years old. The median latency of P100 wave (in milliseconds) at O1 was 123.0 (left) and 118.0 (right); at Oz was 115.0 (left) and 117.5 (right); at O2 was 118.5 (left) and 120.0 (right). Median amplitudes were 3.15 and 3.0 for left and right eye respectively. The conclusions of VEP recordings were: 23.8% subjects suffered from left optic nerve lesion, 14.1% right optic nerve lesion, 45.2% both left and right optic nerve lesion and 16.7% with normal VEP recording.
Conclusion: Optic neuritis patients at Neurology clinic in Sanglah General Hospital was predominantly female with average age 38.4 years old. The characteristics of VEP in this group was prolonged of P100 latency with low amplitudes. The conclusion of VEP recordings was predominantly left and right optic nerve lesion.

Key words: Visual Evoked Potential (VEP), Optic Neuritis, multiple sclerosis