VEP examination of Cognitive Impairment

• Main Authors: Hsi-Pao Hsieh, 謝錫寶
• Other Authors: Cheng, Ching-Ying
• Format: Others
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/01239753760984878730

碩士 === 國立東華大學 === 特殊教育學系 === 103 === Purpose: The purpose of this study is to investigate and analyze the role of visual evoked potential (VEP) parameters in visual function in subjects with cognitive impairment (CI). Methods: In general, norm-referenced data were collected under different visual acuity conditions (uncorrected, 0.3, 0.8, 1.0). In experiment one, twenty-one adults aged from 18 to 27 years with myopia and astigmatism but no ocular or systemic diseases participated in the study. In experiment 2, 5 subjects with CI identified through the educational system also entered the study. Examination included testing of visual acuity (VA), intra-ocular pressure, refraction for spherical equivalent, and both PVEP and FVEP. In addition to statistical correlation of each parameter with CI visual functions, independent t-test, ANOVA, and modulators of VA were analyzed through linear regression analysis that included cumulative adjusted R2 values. Results: Experiment one: (1) No significant difference between PVEP and FVEP responses as a function of age; although (2) PVEP and FVEP amplitude responses in females were both significantly higher than that in males. (3) PVEP amplitude was positively correlated with VA, especially with the 64*64 pattern (amplitude criterion indicated VA lower than 0.3: male, 3.85 or lower; female, 3.95 or lower) and a formulas could be established through linear regression analysis. In addition, (4) elevated refractive error showed slower latency, and (5) the 64*64 PVEP amplitude and the second FVEP amplitude demonstrated the highest reliability. Experiment two: The VA of subjects with CI could be estimated through the formula acquired in experiment one. The results, however, must be examined together with clinical assessment from health practitioners or trained school faculty members. Further, in order to facilitate the examination and avoid behavioral disturbances, CI subjects should be accompanied by their parents, caregivers, or school nurses during examination. Conclusions: The findings can be utilized for the assessment of the VA in subjects with CI. The examination process itself is, however, not without limitations. A streamlined operation will require the cooperation between the examiner, school teachers/nurses, and parents. Key words: visual evoked potential, cognitive impairment, visual acuity, visual disability