Vincent Ajoy, Shetty Rohit, Devi Sathi A V, Kurian Mathew K, Balu Ramgopal, Shetty Bhujang
Department of Electrophysiology, Narayana Nethralaya, Super Specialty Eye Hospital and Post Graduate Institute of Ophthalmology, 121/C, Chord Road, Rajaji Nagar 1st R Block, Bangalore 560010, India.
Doc Ophthalmol. 2010 Aug;121(1):21-7. doi: 10.1007/s10633-010-9227-0. Epub 2010 Mar 25.
The purpose of the study is (1) to demonstrate the anatomical variation of cone photoreceptor density across normal retina as a sectoral amplitude asymmetry of photopic multifocal electroretinogram (mfERG) and (2) to study the potential presence of sequential or differential, functional cone photoreceptor damage in glaucoma using this amplitude asymmetry. A 37-Block scaled mfERG was recorded from 22 controls and 27 glaucoma subjects. The N1 and P1 amplitudes of averaged responses from corresponding zones nasal and temporal to fovea were analyzed for asymmetry in controls and glaucoma subjects. Amplitude asymmetry was demonstrable for both N1 (p < 0.001) and P1 (p < 0.001) parameters in control subjects. Although this amplitude asymmetry was preserved in glaucoma subjects with moderate field defects, it was not demonstrable in patients with advanced field defects. The anatomical variation in cone photoreceptor distribution across normal retina is demonstrated as an amplitude asymmetry in first order kernel responses of mfERG. The cone photoreceptors in the region nasal to fovea appear to be affected only in advanced glaucoma possibly suggesting that photoreceptors could follow a sequential damage like the overlying neuroretinal rim in glaucoma.
（1）通过明视多焦视网膜电图（mfERG）的扇形振幅不对称来证明正常视网膜上视锥光感受器密度的解剖变异；（2）利用这种振幅不对称来研究青光眼患者中视锥光感受器是否存在顺序性或差异性的功能性损伤。对22名对照者和27名青光眼患者记录了37区的mfERG。分析了中央凹鼻侧和颞侧相应区域平均反应的N1和P1振幅在对照者和青光眼患者中的不对称性。对照者的N1（p < 0.001）和P1（p < 0.001）参数均显示出振幅不对称。虽然这种振幅不对称在有中度视野缺损的青光眼患者中得以保留，但在有晚期视野缺损的患者中则未显示出来。正常视网膜上视锥光感受器分布的解剖变异表现为mfERG一阶核反应中的振幅不对称。中央凹鼻侧区域的视锥光感受器似乎仅在晚期青光眼中受到影响，这可能表明光感受器可能像青光眼患者上方的神经视网膜边缘一样遵循顺序性损伤。
