AIM: To analyze and study the changes of intraocular pressure(IOP), visual field and P-ERG on patients with big cup/disk(C/D)in 24h.

METHODS: A total of 120 cases(240 eyes)diagnosed with big C/D(C/D>0.3)were divided into group A(C/D<0.6, 67 cases, 114 eyes)and group B(C/D≥0.6, 73 cases, 126 eyes). Forty cases(80 eyes)with small C/D(C/D≤0.3)were chosen as control group. All cases underwent 24h IOP examination, vision examination of 30-2 SITA-standard static threshold and pattern electroretinogram(P-ERG)examination. The differences between the examination indexes of the three groups were analyzed.

RESULTS: There was no significant statistical difference in the 24h average IOP(P>0.05)among the three groups, while the amplitudes had significant statistical differences(P<0.05). Compared with the control group, the IOP amplitudes of group B were obviously higher, and the difference was of statistical significance(P<0.05). In terms of static threshold visual fields, the mean deviations(MD)and pattern standard deviations(PSD)of the three groups had significant statistical differences(P<0.05). Comparison between every two groups: compared with the control group, the MD and the PSD were significantly increased in group B, and the difference was of statistical significance(P<0.05); while there was no significant statistical difference in group A(P>0.05); Compared with group A, the MD and the PSD were significantly higher in group B, and the difference was of statistical significance(P<0.05). In terms of P-ERG examination, there was no significant statistical difference in P50's latent periods among the three groups(P>0.05), but there were significant statistical differences in amplitudes(P<0.05). Comparison between every two groups: compared with the control group, the P50's amplitude was significantly decreased in group B, and the difference was of statistical significance(P<0.05), while there was no significant statistical difference in group A(P>0.05); Compared with group A, the P50's amplitude of group B was significantly lower, and the difference was of statistical significance(P<0.05).

CONCLUSION: When the patients' C/D is no less than 0.6, there are obvious changes of 24h IOP, static threshold visual field and P-ERG's P50 wave. For patients with big C/D, a single IOP examination is far from sufficient, so an in-depth visual function examination should be performed. Meanwhile, it's feasible to regard C/D 0.6 as a screening criterion for suspected glaucoma.