Atchaneeyasakul L O, Trinavarat A, Wanumkarng N, Samsen P, Thanasombatsakul N
Department of Ophthalmology, Siriraj Hospital Mahidol University, Bangkok, Thailand.
Eur J Ophthalmol. 2003 Oct;13(8):702-9. doi: 10.1177/112067210301300807.
To evaluate the value of electroretinogram (ERG) and visual evoked potentials (VEP) in children with nonsyndromic microcephaly.
In this observational case series, six children with nonsyndromic microcephaly aged 8.5 to 158 months were examined. Main outcome measures included the amplitude of the flash ERG (photopic, flickering, scotopic, and dark-adapted responses), the amplitude and latency of the VEP (flash or pattern-reversal stimulus), visual acuity, slit-lamp biomicroscopy, and indirect ophthalmoscopy.
Three children demonstrated normal fundus appearances, ERG, and VEP responses: two in this group demonstrated poor vision and brain computed tomography in the third showed schizencephaly. The remaining three children demonstrated abnormal ERG with predominant reduction in photopic amplitudes. Retinal pigmentary granularities were detected in two children in this group, one of whom has poor vision, generalized brain atrophy, and 40% reduction in VEP amplitudes.
Abnormal ERG is not uncommon among children with nonsyndromic microcephaly. Although cone photoreceptors are affected more than rods, this does not anticipate poor vision. It appears that defects in posterior visual pathway or developmental malformations of the brain should be responsible for poor visual function in nonsyndromic microcephaly.
评估视网膜电图（ERG）和视觉诱发电位（VEP）在非综合征性小头畸形儿童中的价值。
在这个观察性病例系列中，对6名年龄在8.5至158个月的非综合征性小头畸形儿童进行了检查。主要观察指标包括闪光ERG的振幅（明视、闪烁、暗视和暗适应反应）、VEP的振幅和潜伏期（闪光或图形翻转刺激）、视力、裂隙灯生物显微镜检查和间接检眼镜检查。
3名儿童的眼底表现、ERG和VEP反应正常：该组中的2名儿童视力较差，第3名儿童的脑部计算机断层扫描显示脑裂畸形。其余3名儿童的ERG异常，主要表现为明视振幅降低。该组中的2名儿童检测到视网膜色素颗粒，其中1名视力差、有广泛性脑萎缩且VEP振幅降低40%。
异常ERG在非综合征性小头畸形儿童中并不少见。虽然视锥细胞比视杆细胞受影响更大，但这并不预示视力差。看来，非综合征性小头畸形儿童视觉功能差应归因于视觉后通路缺陷或脑部发育畸形。
