Abstract：
Visual electrophysiology may be used to assess visual potential in infants with congenital corneal opacities (CCO). It is essential to recognize confounding effects from these opacities on the flash electroretinogram (ERG).
ERGs were recorded in awake children employing skin electrodes placed at the lower eyelid crease, both referred to a midfrontal electrode (Fz). A hand-held stimulator was used to present a mixed rod-cone and a dim white stimulus. Recordings were carried out before and after penetrating keratoplasty (PK), when performed.
Five infants under the age of 12 months with visually significant CCO were evaluated. In all cases, initial ERGs employing the mixed rod-cone stimulus showed well-defined a-wave with reduced amplitude b-wave. Reduction of stimulus intensity resulted in an increase in the b-wave and normalization of the b:a ratio from 1.1 (range 0.7 to 1.3) to 2.8 (range 1.5 to 4.3). In three cases who underwent PK, the postoperative ERGs recorded with a mixed rod-cone stimulus were normal in waveform shape with a mean b:a ratio of 2.0 (range 1.7 to 3.0).
Selective reduction of the scotopic bright flash ERG b-wave is typically caused by retinal dysfunction that is post-phototransduction or inner retinal. In infants with CCO, scotopic ERGs to bright flashes can show a reduced b:a ratio that improves or normalizes either after PK or stimulus intensity reduction. The study highlights that media opacity can contribute to the generation of an ERG with reduced b-wave in the absence of inner retinal dysfunction.
ERGs were recorded in awake children employing skin electrodes placed at the lower eyelid crease, both referred to a midfrontal electrode (Fz). A hand-held stimulator was used to present a mixed rod-cone and a dim white stimulus. Recordings were carried out before and after penetrating keratoplasty (PK), when performed.
Five infants under the age of 12 months with visually significant CCO were evaluated. In all cases, initial ERGs employing the mixed rod-cone stimulus showed well-defined a-wave with reduced amplitude b-wave. Reduction of stimulus intensity resulted in an increase in the b-wave and normalization of the b:a ratio from 1.1 (range 0.7 to 1.3) to 2.8 (range 1.5 to 4.3). In three cases who underwent PK, the postoperative ERGs recorded with a mixed rod-cone stimulus were normal in waveform shape with a mean b:a ratio of 2.0 (range 1.7 to 3.0).
Selective reduction of the scotopic bright flash ERG b-wave is typically caused by retinal dysfunction that is post-phototransduction or inner retinal. In infants with CCO, scotopic ERGs to bright flashes can show a reduced b:a ratio that improves or normalizes either after PK or stimulus intensity reduction. The study highlights that media opacity can contribute to the generation of an ERG with reduced b-wave in the absence of inner retinal dysfunction.
摘要：
未经证实：视觉电生理学可用于评估先天性角膜混浊（CCO）婴儿的视觉潜能。必须认识到这些混浊对闪光视网膜电图（ERG）的混杂作用。
UNASSIGNED：在使用皮肤电极放置在下眼睑折痕的清醒儿童中记录ERG，两者都指的是中额电极(Fz)。手持刺激器用于呈现混合的棒锥和暗淡的白色刺激。在穿透性角膜移植术（PK）之前和之后进行记录，当执行。
未经评估：对5名年龄在12个月以下且具有视觉显著性CCO的婴儿进行评估。在所有情况下,使用混合棒锥刺激的初始ERG显示出定义明确的a波，振幅降低的b波。刺激强度的降低导致b波的增加和b：a比从1.1（范围0.7至1.3）到2.8（范围1.5至4.3）的归一化。在三个接受PK的病例中，使用混合棒锥刺激记录的术后ERG波形正常,平均b:a比为2.0(范围1.7~3.0).
非ASSIGNED：暗视明亮闪光ERGb波的选择性减少通常是由于光传导后或内部视网膜功能障碍引起的。在患有CCO的婴儿中，暗视ERG到明亮的闪光可以显示出降低的b：在PK或刺激强度降低后改善或正常化的比率。该研究强调，在没有内部视网膜功能障碍的情况下，介质不透明可能有助于产生b波减少的ERG。
UNASSIGNED：在使用皮肤电极放置在下眼睑折痕的清醒儿童中记录ERG，两者都指的是中额电极(Fz)。手持刺激器用于呈现混合的棒锥和暗淡的白色刺激。在穿透性角膜移植术（PK）之前和之后进行记录，当执行。
未经评估：对5名年龄在12个月以下且具有视觉显著性CCO的婴儿进行评估。在所有情况下,使用混合棒锥刺激的初始ERG显示出定义明确的a波，振幅降低的b波。刺激强度的降低导致b波的增加和b：a比从1.1（范围0.7至1.3）到2.8（范围1.5至4.3）的归一化。在三个接受PK的病例中，使用混合棒锥刺激记录的术后ERG波形正常,平均b:a比为2.0(范围1.7~3.0).
非ASSIGNED：暗视明亮闪光ERGb波的选择性减少通常是由于光传导后或内部视网膜功能障碍引起的。在患有CCO的婴儿中，暗视ERG到明亮的闪光可以显示出降低的b：在PK或刺激强度降低后改善或正常化的比率。该研究强调，在没有内部视网膜功能障碍的情况下，介质不透明可能有助于产生b波减少的ERG。
