[Changes of color pattern reversal visual evoked potential of primary glaucoma].

OBJECTIVE: To investigate the changes of color pattern reversal visual evoked potential (CPR-VEP)of primary glaucoma using different temporal frequencies, and to search for the best temporal frequency parameters and color parameters. METHODS: Vision Monitor visual electrophysiograph (Métrovision, France) was used to record CPR-VEP at different temporal frequencies (1, 2, 4, 8, 16, and 32 Hz) and different color stimulations (black/white, red/green, blue/yellow) in 41 cases (70 eyes) with primary glaucoma (glaucoma group) and 13 normal subjects (26 eyes) (normal control group). P100 wave amplitudes were compared. RESULTS: (1) In the normal control group, P100 amplitudes declined while the temporal frequency of black/white stimulation was increasing, but they had peaks at 2 Hz and 8 Hz red/green stimulation and blue/yellow stimulation. (2) In the glaucoma group, CPR-VEP P100 declined while temporal frequency was increasing under 3 color stimulations, but had a peak at 8 Hz. At 2 Hz-16 Hz, P100 amplitudes were related with the mean defect of Humphrey visual field, especially with all 3 color stimulations at 8 Hz and with blue/yellow stimulation at 2 Hz and 16 Hz. (3) P100 amplitude was most different under the 3 color stimulations between the 2 groups at 8 Hz. CONCLUSION: The changes of CPR-VEP P(100) amplitude can objectively reflect the glaucoma visual function damage. CPR-VEP P100 amplitude has certain value in studying glaucoma under different color stimulations (black/white, red/green, blue/yellow) at 8 Hz, and blue/yellow stimulation at 2 Hz and 16 Hz.

[Dynamic expression of VIPR2 in form deprivation myopia].

OBJECTIVE: To investigate the dynamic expression and significance of vasoactive intestinal peptide receptor 2 (VIPR2) on retina-choroid-clera in high myopia. METHODS: Twenty-one yellow chicks of 1 day old were used in the research. The right eyes were the experimental group, covered continuously for 1 week, 2 weeks and 4 weeks respectively. The left eyes were not covered as the normal control group. Both groups were detected diopter degrees using retinoscopic refraction, determinated eyeball axis using ophthalmology ultra-A, and investigated VIPR2 expression on retina-choroid-sclera in both groups at three stages by SP immunohistochemical staining. RESULTS: The experimental eyes changed from hypermetropia at pre-experiment to high myopia during the experiment stages, and the diopter degrees were deeper and eyeball axis was longer along with the period of being covered. Both groups had strong expression of VIPR2 on photoreceptor-outer segment of the retina and choroids. The expression was down-regulated with the time in both groups. Compared with the control group, VIPR2 expression of the experimental group was significantly up-regulated (P < 0.05). CONCLUSION: Form deprivation could induce high myopia. The expression of VIPR2 existed on photoreceptor-outer segment of the retina and choroids. VIPR2 may play an important role on the formation and development of myopia.