Kandarakis Stylianos A, Doumazos Leonidas, Karageorgiou Georgia, Petrou Petros, Doumazos Spyridon, Malamos Panagiotis, Georgalas Ilias
1st Ophthalmology Department, "G. Gennimatas" Hospital, National and Kapodistrian University of Athens, Athens, Greece.
Case Rep Ophthalmol. 2024 Jul 12;15(1):552-558. doi: 10.1159/000539425. eCollection 2024 Jan-Dec.
Iris retraction syndrome (IRS) is a rare clinical condition characterized by a backbowing of the iris positioned on the lens with a complete pupillary block. Immune checkpoint inhibitors (ICIs) are a new class of immunomodulating agents used in cancer therapy, and although they have high response rates, ophthalmic-related side effects have been reported. We report a rare case of bilateral IRS with hypotony after therapy with nivolumab.
We present a case of bilateral IRS with hypotony, 3 mm Hg OD and 5 mm Hg OS, after therapy with nivolumab. The patient presented with decreased vision, corneal edema, keratic precipitates, deep anterior chamber with posterior synechiae, and hypotony maculopathy. Anterior segment OCT revealed a sharp posterior displacement of the iridolenticular diaphragm consistent with IRS. Discontinuation of nivolumab until ocular improvement was suggested, following oncologic consultation. Four months later, the patient exhibited iris bombé with angle closure and increased IOP. This was managed with phacoemulsification and concomitant surgical iridectomy. One month after surgery, the patient's IOP had returned to physiologic values, and the iris configuration had returned to normal.
The exact mechanism of IRS remains unclear, but it is suggested that an aqueous imbalance, in conjunction with uveitis and hypotony, creates an anterio-posterior movement of the iridolenticular diaphragm when the pupillary block is present. Our case highlights the importance of monitoring patients receiving ICIs for ophthalmic adverse effects and prompt management to prevent permanent visual damage. In conclusion, this is the first reported case of IRS after therapy with ICIs. Further research is needed to fully understand the exact mechanism by which it is induced.
虹膜后缩综合征（IRS）是一种罕见的临床病症，其特征为位于晶状体上的虹膜向后弯曲并伴有完全性瞳孔阻滞。免疫检查点抑制剂（ICIs）是用于癌症治疗的一类新型免疫调节剂，尽管它们具有较高的缓解率，但已报道有与眼科相关的副作用。我们报告一例使用纳武单抗治疗后出现双侧IRS并伴有低眼压的罕见病例。
我们报告一例使用纳武单抗治疗后出现双侧IRS并伴有低眼压的病例，右眼眼压3 mmHg，左眼眼压5 mmHg。患者出现视力下降、角膜水肿、角膜后沉着物、伴有虹膜后粘连的深前房以及黄斑病变性低眼压。前段光学相干断层扫描（OCT）显示虹膜晶状体隔明显向后移位，符合IRS表现。经肿瘤学会诊后，建议停用纳武单抗直至眼部情况改善。四个月后，患者出现虹膜膨隆伴房角关闭和眼压升高。对此采用了超声乳化白内障吸除术并同期行手术虹膜切除术进行处理。术后一个月，患者眼压恢复至生理值，虹膜形态恢复正常。
IRS的确切机制尚不清楚，但有人认为，当存在瞳孔阻滞时，房水失衡与葡萄膜炎和低眼压共同作用，会导致虹膜晶状体隔前后移动。我们的病例突出了监测接受ICIs治疗患者眼部不良反应并及时处理以防止永久性视力损害的重要性。总之，这是首例报道的ICIs治疗后发生IRS的病例。需要进一步研究以充分了解其诱发的确切机制。
