Pattern visual evoked potential in hypothyroid patients

• Published in: Documenta ophthalmologica Vol. 138; no. 2; pp. 77 - 84
• Main Authors: Azimi, Abbas, Bonakdaran, Shokoufeh, Heravian, Javad, layegh, Parvin, Yazdani, Negareh, Alborzi, Maryam
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2019; Springer Nature B.V
• Subjects: Adult; Electroretinography; Evoked Potentials, Visual - physiology; Female; Humans; Hypothyroidism; Hypothyroidism - physiopathology; Latency; Medicine; Medicine & Public Health; Middle Aged; Ophthalmology; Original Research Article; Retina - physiopathology; Visual evoked potentials; Visual Pathways - physiopathology; Young Adult; Visual evoked potential; Visual pathway; Hypothyroidism; Central nervous system
• ISSN: 0012-4486; 1573-2622; 1573-2622
• DOI: 10.1007/s10633-019-09670-1

Purpose To investigate the functional integrity of visual pathway in hypothyroid patients by pattern visual evoked potential (PVEP). Methods We enrolled 36 female patients with history of hypothyroidism (18 overt and 18 subclinical) aged 20 to 60 years and 36 healthy women of similar age (control group). All subjects had a complete ophthalmic examination. For VEP testing, subjects were exposed to checks subtending a visual angle of 15 and 60 min of arc. Results For the 15 min of arc check size, the mean P100 latency was significantly delayed (113 milliseconds (ms)) and amplitude significantly reduced (9.2 microvolts (µv)) in the hypothyroidism group compared with controls (109.6 ms and 11.6 µv, respectively). For this 15′ check size, the group differences were related to significantly increased latency and reduced amplitude of responses in the group with overt hypothyroidism compared with controls. There was no difference between the groups (hypothyroid vs control) with 60 min of arc check size. There was a significant correlation between severity of the disease and PVEP component. Conclusions In conclusion, low levels of circulating hypothyroid hormone are associated with delay in the pattern VEP to small check sizes. This CNS involvement worsens in patients with greater severity and duration of hypothyroidism.