摘要
目的 研究老年黄斑变性 (age -relatedmaculardegeneration ,ARMD)早期患者眼底后极部视锥细胞视杆细胞功能变化。方法 在 2 5例ARMD早期患者和 16例正常老年人分别检测中央 2 5°81个位点暗视敏感度和明视敏感度 ,记录多焦视网膜电图 (multifocalelectroretinography ,mfERG)和视杆细胞mfERG。比较两组暗视、明视敏感度和N1波、P1波的振幅和潜伏期。暗视敏感度检测是暗适应后用蓝光刺激 (W 47b ,45 0nm )、无背景光 ;明视敏感度检测用白光刺激、背景光3 1 4asb。视杆细胞mfERG是暗适应后用低强度 (最大亮度为 0 85cd/m2 )的蓝光刺激 (W 47b ,45 0nm) ,慢刺激频率 ( 3个空白帧 )。结果 ARMD组暗视和明视敏感度比正常老年对照组降低 ,暗视敏感度降低更明显。暗视敏感度降低随离心度增加而减少 ,在距中心凹 2 5°～ 5°下降最明显。AR MD组视杆细胞mfERG 1环N1和P1波振幅明显降低。结论 ARMD早期视杆细胞功能下降 ,中心凹旁下降最明显 ,进一步验证ARMD视杆细胞易感性假说。
Objective To measure local cone and rod function of the central retina and investigate whether there is rod system dysfunction in early stage of age-related macular degeneration(ARMD)and test the hypothesis of rod vulnerability in ARMD.Methods Scotopic (450-nm stimulus,0 background)and photopic (white,31 4asb background)sensitivity were measured at 81 loci in central 25° of retina in 25 patients with early stage ARMD,multifocal electroretinography(mfERG) and rod mfERG were recorded as well.The results were compared with 16 older adult normal controls.The rod mfERG were recording using an array of 61 equally sized hexagons.The stimulus display was viewed through a blue filter(W47b).The stimulus sequence was slowed with the insertion of three blank frames(3F).The luminance of the hexagons was 0 85cd/m\+2(bright)and -log1 61×10 -2 cd/m\+2*(dim).Results Mean scotopic sensitivity was significantly lower of ARMD patients than of normal subjects.The ratio of reduced scotopic sensitivity was higher than of photopic sensitivity in patients with scotopic and photopic senstivities losses.Scotopic sensitivity losses decreased with increasing eccentricity,and the greatest deficit was from 2 5° to 5 0°.The amplitudes of N1 and P1 wave in 1 ring of rod mfERG were significantly lower of ARMD patients than of normal subjects.Conclusions Rod function decreased and parafoveal rod cells had a selective vulnerability in early ARMD patients.Rod function testing in macula may be a useful tool to measure the fundus pathology and diagnose of ARMD.
出处
《中国实用眼科杂志》
CSCD
北大核心
2004年第4期255-259,共5页
Chinese Journal of Practical Ophthalmology
