Ishikawa Kohei, Kondo Mineo, Ito Yasuki, Kikuchi Masato, Nishihara Hiroaki, Piao Chang-Hua, Sugita Tadasu, Terasaki Hiroko
Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Invest Ophthalmol Vis Sci. 2007 May;48(5):2254-9. doi: 10.1167/iovs.06-1277.
It is known that the amplitudes of the multifocal electroretinograms are generally reduced soon after photodynamic therapy (PDT). The purpose of this study was to determine whether this amplitude reduction correlates with the changes in macular thickness or with changes in choroidal circulation.
Thirty-seven eyes that were successfully treated by PDT were studied. Focal macular electroretinograms (fmERGs) and optical coherence tomography were performed before and 1 week, 1 month, and 3 months after PDT. Indocyanine green angiography was performed before and 3 months after PDT. The indocyanine green angiographic findings were classified into two groups: group A, with indistinct hypofluorescence at the site of the PDT, and group B, with well-defined hypofluorescence borders coinciding with the site of the PDT.
The mean amplitudes of the fmERGs were significantly reduced at 1 week after PDT (P < 0.05). The correlations between the changes in the amplitude of the fmERG and the changes in macular thickness were not significant. Sixteen (43%) of the study eyes were classified into group A and 21 (57%) into group B by indocyanine green angiography. The mean ratio of the fmERG b-wave 1 week after PDT to that before PDT was 1.14 +/- 0.62 in group A and 0.65 +/- 0.29 in group B. This difference was statistically significant (P < 0.01).
One of the possibilities that could explain the reduction in the amplitude of the fmERGs soon after PDT is the reduction in choroidal circulation caused by the PDT.
众所周知，光动力疗法（PDT）后不久，多焦视网膜电图的振幅通常会降低。本研究的目的是确定这种振幅降低是否与黄斑厚度的变化或脉络膜循环的变化相关。
对37只成功接受PDT治疗的眼睛进行了研究。在PDT前以及PDT后1周、1个月和3个月进行了黄斑局部视网膜电图（fmERGs）和光学相干断层扫描。在PDT前和PDT后3个月进行了吲哚青绿血管造影。吲哚青绿血管造影结果分为两组：A组，PDT部位出现模糊的低荧光；B组，PDT部位出现边界清晰的低荧光，与PDT部位相符。
PDT后1周，fmERGs的平均振幅显著降低（P < 0.05）。fmERG振幅变化与黄斑厚度变化之间的相关性不显著。通过吲哚青绿血管造影，16只（43%）研究眼被分为A组，21只（57%）被分为B组。PDT后1周A组fmERG b波与PDT前的平均比值为1.14±0.62，B组为0.65±0.29。这种差异具有统计学意义（P < 0.01）。
PDT后不久fmERGs振幅降低的一种可能解释是PDT导致脉络膜循环减少。
