King's College Hospital, London, United Kingdom.
Retina. 2013 Jun;33(6):1232-40. doi: 10.1097/IAE.0b013e3182794b22.
To determine if epimacular brachytherapy is associated with reduced retinal sensitivity or choroidal nonperfusion.
A prospective intervention case series of 12 participants with neovascular age-related macular degeneration requiring frequent ranibizumab underwent vitrectomy and epimacular brachytherapy. The Strontium 90/Yttrium 90 source delivered a single 24-Gy dose at the center of the treatment zone. The dose attenuated with increasing distance from the source. Microperimetry and indocyanine green angiography were performed at baseline and 12 months. The main outcome measures were mean sensitivity and choroidal nonperfusion. A linear mixed model was used to assess the association between the dose of radiation and the change in mean sensitivity.
Mean visual acuity remained within 1 letter of baseline at 12 months (-0.33 ± 13.2 letters). There was no statistically significant change in mean sensitivity within the neovascular age-related macular degeneration lesion area (gain of 0.94 ± 3.25 dB; P = 0.339) or in neighboring unaffected retina (0.66 ± 4.14 dB; P = 0.594), defined using fluorescein angiography. Within the lesion area, mean sensitivity improved by an average of 0.23 ± 0.16 dB (P = 0.006) for every additional gray of radiation received. Indocyanine green angiography failed to demonstrate any choroidal nonperfusion or radiation damage at 12 months after the treatment.
Stable retinal sensitivity in areas not manifestly affected by neovascular age-related macular degeneration suggests that epimacular brachytherapy does not damage retinal function. The presence of a dose response suggests that the positive effect of epimacular brachytherapy relates more to beta irradiation than vitrectomy.
确定后极部巩膜光凝术是否与视网膜敏感性降低或脉络膜无灌注有关。
对 12 例需要频繁接受雷珠单抗治疗的新生血管性年龄相关性黄斑变性患者进行前瞻性干预病例系列研究，所有患者均接受玻璃体切除术和后极部巩膜光凝术。锶 90/钇 90 源在治疗区中央给予单次 24Gy 剂量，剂量随距源距离的增加而衰减。在基线和 12 个月时进行微视野计和吲哚青绿血管造影检查。主要观察指标为平均敏感性和脉络膜无灌注。采用线性混合模型评估辐射剂量与平均敏感性变化之间的关系。
平均视力在 12 个月时仍保持在基线水平（-0.33±13.2 个字母）。新生血管性年龄相关性黄斑变性病变区（增加 0.94±3.25dB；P=0.339）或相邻未受影响的视网膜（增加 0.66±4.14dB；P=0.594）内平均敏感性无统计学显著变化，根据荧光素血管造影定义。在病变区内，平均敏感性平均提高了 0.23±0.16dB（P=0.006），而接受的额外辐射灰度增加 1 个。吲哚青绿血管造影在治疗后 12 个月时未显示任何脉络膜无灌注或辐射损伤。
未明显受新生血管性年龄相关性黄斑变性影响的区域视网膜敏感性稳定，表明后极部巩膜光凝术不会损害视网膜功能。剂量反应的存在提示后极部巩膜光凝术的积极作用更多地与β射线照射有关，而不是玻璃体切除术。
