IRCCS-Fondazione Bietti, Rome, Italy.
Medical Oncology, SG Moscati Hospital, Taranto, Italy.
Graefes Arch Clin Exp Ophthalmol. 2021 Dec;259(12):3721-3727. doi: 10.1007/s00417-021-05350-6. Epub 2021 Aug 26.
The purpose of this study is to investigate whether phacoemulsification can generate aerosolized single-stranded RNA (ssRNA) and retain sequence integrity using an artificial eye model for experimental cataract surgery.
A simulation of cataract surgery was performed using an anterior chamber eye model filled with an ssRNA probe at different scalar dilutions (kanamycin positive control ssRNA). A plastic conical cage was built over the artificial eye surface of the mock-up. A total of 24 tests (twice reproduced) were performed, and five nitrocellulose strips were placed 15 cm from the artificial surface of the mock-up and used to collect aerosol particles, from each experiment. Phaco-activity was mimicked using a phacoemulsification equipped with a 2.75-mm tip, and strips were removed at the end of the procedure. RNA extraction, reverse transcription, and agarose gel electrophoresis were performed and compared.
Strips collected aerosol droplets enriched with ssRNA, mainly at the higher concentrations tested, compared to related untouched standard solutions. Complementary DNA (cDNA) synthesis confirmed the presence of intact ssRNA fragments. As observed from densitometric analysis of resolved RNA in extracted samples and cDNA bands after retro-transcription, lower concentrations of ssRNA were also detected.
As the main output of the study, the phaco-generated aerosol can deliver an intact ssRNA sequence. Since the aerosol can potentially reach the operator's face, any biological agent (virus/bacteria) potentially inside the anterior chamber of a patient undergoing cataract surgery, eventually escaping from biomolecular checks, can be potentially infective for operators. The data reported herein suggest that collective versus individual protective countermeasures should always be encouraged in ocular surgery and should not be restricted to coronavirus disease emergencies.
本研究旨在通过白内障手术实验用人工眼前房模型，研究超声乳化是否会产生气溶胶化的单链 RNA（ssRNA）并保持序列完整性。
采用含有 ssRNA 探针的前房模型模拟白内障手术，以不同比例稀释（庆大霉素阳性对照 ssRNA）。在模拟眼前表面构建一个塑料圆锥形笼。共进行了 24 次测试（两次重复），每次实验将 5 个硝酸纤维素条放置在距模拟人工表面 15cm 处，以收集气溶胶颗粒。使用配备 2.75mm 尖端的超声乳化仪模拟超声乳化，在程序结束时取出条带。进行 RNA 提取、逆转录和琼脂糖凝胶电泳，并进行比较。
与相关未接触的标准溶液相比，条带收集的富含 ssRNA 的气溶胶液滴主要在较高浓度下富集。互补 DNA（cDNA）合成证实了完整 ssRNA 片段的存在。从提取样品中经逆转录后解析 RNA 的密度分析和 cDNA 条带来看，也检测到较低浓度的 ssRNA。
作为本研究的主要结果，超声乳化产生的气溶胶可以传递完整的 ssRNA 序列。由于气溶胶可能会到达操作人员的面部，因此任何可能存在于接受白内障手术的患者前房内的生物制剂（病毒/细菌），最终逃脱生物分子检查，都可能对操作人员具有感染性。本文报道的数据表明，在眼部手术中，应始终鼓励采取集体而非个体的保护措施，而不应仅限于冠状病毒病紧急情况。
