鼻泪管阻塞（NLDO）是高剂量放射性碘（RAI）治疗甲状腺癌的不良反应。目前尚无既定的预防措施。本研究评估了不含防腐剂的人工泪液 (PFAT) 是否可以降低接受放射性碘 (RAI) 治疗甲状腺癌的患者泪液中 131I 碘化钠 (I-131) 的活性，并有可能作为 RAI 相关的预防措施NLDO。这项非随机前瞻性试点临床试验招募了佩戴隐形眼镜、接受 RAI 治疗甲状腺癌的患者，从 RAI 摄入当天开始，自行将 PFAT 注射到右眼，为期 4 天。左眼是控制者。佩戴隐形眼镜时，患者按照以下步骤自我管理 PFAT：第 1 天：每 15 分钟一次，持续 2 小时，然后每 30 分钟一次，直至就寝时间；第 2 天：每小时一次，持续至少 12 小时；第 3 天：每天四次；以及第4天：每天两次。每天更换隐形眼镜，一周后收集所有镜片。 I-131 活性水平通过井计数器测量、衰减校正并转换为贝克勒尔 (Bq) 单位。进行统计分析以比较实验眼和对照眼的 I-131 活性。8 名患者的 16 只眼接受了平均 145.7 毫居里（范围 108-159）的 I-131 治疗乳头状甲状腺癌。第一天，人工泪液使实验眼中 I-131 活性的几何平均数降低了 26% (p=0.008)。人工泪液还将四天内的几何平均曲线下面积 (AUC) 降低了 23% (p=0.002)。甲状腺癌 RAI 治疗后泪液中存在 I-131。从 RAI 摄入当天开始频繁进行 PFAT 可能会降低泪液中 I-131 的水平。这一发现可能对降低 NLDO 风险产生影响。未来需要进行多中心临床试验来确定 RAI 治疗后使用人工泪液是否可以降低 NLDO.NCT04327999 的风险。

Nasolacrimal duct obstruction (NLDO) is an adverse effect of high dose radioactive iodine (RAI) therapy for thyroid carcinoma. There are currently no established preventive measures. This study assesses whether preservative free artificial tears (PFATs) can decrease the 131I sodium iodide (I-131) activity in the tears of patients following radioactive iodine (RAI) therapy for thyroid carcinoma, and potentially serve as a preventive measure for RAI-associated NLDO.This non-randomized prospective pilot clinical trial recruited contact-lens wearing patients undergoing RAI therapy for thyroid cancer to self-administer PFATs into the right eye for 4 days starting on the day of RAI ingestion. Left eyes were the controls. While wearing contacts, patients self-administered PFATs per the following - Day 1: every 15 minutes for 2 hours, then every 30 minutes until bedtime, Day 2: every hour for at least 12 hours, Day 3: four times a day, and Day 4: two times a day. Contact lenses were changed daily, and all lenses were collected one week later. Levels of I-131 activity were measured by a well counter, decay-corrected, and converted to units of Bequerel (Bq). Statistical analyses were performed to compare the I-131 activities of the experimental and control eyes.Sixteen eyes of 8 patients treated with an average of 145.7 millicuries (range 108-159) of I-131 for papillary thyroid cancer were included. On Day 1, artificial tears decreased the geometric mean I-131 activity by 26% in the experimental eyes (p=0.008). Artificial tears also decreased the geometric mean area under the curve (AUC) over four days by 23% (p=0.002).I-131 is present in the tears following RAI therapy for thyroid carcinoma. Frequent PFATs starting on the day of RAI ingestion may decrease the level of I-131 in the tears. This finding could have implications for lowering the risk of NLDO. Future multi-center clinical trials are needed to determine if the use of artificial tears after RAI therapy may decrease the risk of NLDO.NCT04327999.