目的：描述使用闭合性结膜外途径双重植入Xen45凝胶支架（Xen）的结果。
方法：回顾性单中心病例系列原发性开角型青光眼患者，在没有结膜开放的情况下，通过abexterno技术在同一只眼睛植入第二个Xen后，进行至少六个月的随访。
结果：纳入8例患者的8只假晶状体眼。眼压（IOP）从术前的30±2.6mmHg下降到第一次Xen植入后一个月的22.4±2.3mmHg（平均差：-7.6mmHg[95％置信区间：-9.4，-5.9mmHg]，p=0.0092)。然后植入第二个Xen以达到目标IOP。术中、术后无明显并发症。第二次植入后6个月，眼压降至16.1±2.7mmHg（平均差：-6.3mmHg[95%置信区间：-7.2，-5.3mmHg]，p=0.0183)；然而，3例患者需要药物治疗以进一步降低IOP至目标值。
结论：在结膜闭合的情况下，使用abexterno方法序贯植入两个Xen45凝胶支架似乎是一个有希望的手术，在这个小病例系列中显示出良好的安全性和有效性。该试验数据可能为进一步研究以评估该程序的安全性和有效性铺平道路。
OBJECTIVE: To describe the outcomes of double implantation of Xen 45 Gel Stent (Xen) using an ab externo approach with closed conjunctiva.
METHODS: Retrospective single-centre case series of primary open-angle glaucoma patients with at least six months of follow-up after implantation of a second Xen in the same eye via ab externo technique without conjunctival opening.
RESULTS: Eight pseudophakic eyes of 8 patients were included. Intraocular pressure (IOP) dropped from 30 ± 2.6 mmHg pre-operatively to 22.4 ± 2.3 mmHg one month after the first Xen implant (mean difference: -7.6 mmHg [95% confidence interval: -9.4, -5.9 mmHg], p = 0.0092). A second Xen was then implanted to achieve the target IOP. The procedure showed no significant intraoperative or postoperative complications. The IOP dropped to 16.1 ± 2.7 mmHg six months following this second implant (mean difference: -6.3 mmHg [95% confidence interval: -7.2, -5.3 mmHg], p = 0.0183); however, 3 patients needed medical therapy to further reduce the IOP towards the target value.
CONCLUSIONS: Sequential implantation of two Xen 45 Gel Stents using an ab externo approach with closed conjunctiva appears a promising procedure that showed a favorable safety and efficacy profile in this small case series. This pilot data might pave the way for further studies to evaluate the safety and efficacy of the procedure.
