[The analysis of pattern visual evoked potential in obstructive sleep apnea syndrome].

OBJECTIVE

To objectively evaluate visual function by pattern visual evoked potential (PVEP) and its related factors in patients with obstructive sleep apnea syndrome (OSAS)without any ocular symptoms.

METHODS

Eighty-three newly diagnosed OSAS and 18 normal subjects were enrolled in the study. The OSAS patients were divided into mild (n=11), moderate(n=17) and severe (n=55) groups based on the apnea-hypopnea index(AHI). Before the polysomnography(PSG) test, all participants underwent a PVEP examination measuring the latency and amplitude of P100.

RESULTS

Compared to healthy controls, the latency of P100 was significantly increased in OSAS patients [controls group: 97(95-100) ms, mild OSAS group: 101(98-103) ms, moderate OSAS group: 101(98-105) ms, severe OSAS group: 105(101-108) ms, all P<0.05], and the amplitude of P100 was significantly reduced [controls group: 9(8-10) μV, mild OSAS group: 7(5-8) μV, moderate OSAS group: 6(5-7) μV, severe OSAS group: 6(4-7) μV, all P<0.05]. The severe group showed significantly longer latency of P100 when compared with mild and moderate groups(P<0.05). In the OSAS patients, univariate analysis showed that, the latency of P100 was correlated with ODI, T90, AHI, sleep efficiency, minimum SaO2, and mean SaO2, and the amplitude of P100 was statistically associated with sleep efficiency .But the stepwise multiple linear regression analysis revealed that only AHI was significantly correlated with the latency of P100 (r=0.275, P<0.01).

CONCLUSION

Abnormal PVEP was found in patients with OSAS without any clinical manifestations of the optic neuropathy. The dysfunction of optic nerve was significantly associated with AHI and sleep efficiency.