Dr. Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, India.
Department of Pathology, All India Institute of Medical Sciences, New Delhi, India.
Indian J Ophthalmol. 2023 Jun;71(6):2436-2442. doi: 10.4103/ijo.IJO_2133_22.
To analyze the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in tears/conjunctival epithelium and assess the cytomorphological changes in the conjunctival epithelium of coronavirus disease 2019 (COVID-19) patients.
In this pilot study, patients with moderate to severe COVID-19 were recruited from the COVID ward/intensive care unit of the institute. Tears and conjunctival swabs were collected from COVID-19 patients and sent to the virology laboratory for reverse transcription polymerase chain reaction (RT-PCR) testing. Conjunctival swabs were used to prepare smears, which underwent cytological evaluation and immunocytochemistry for SARS-CoV-2 nucleocapsid protein.
Forty-two patients were included. The mean age of participants was 48.61 (range: 5-75) years. Seven (16.6%) patients tested positive for SARS-CoV-2 ribonucleic acid in tears samples, four (9.5%) of which were positive on conjunctival swab by RT-PCR in the first test. Cytomorphological changes were observed significantly more in smears from patients with positive RT-PCR on tear samples, including bi-/multi-nucleation (p = 0.01), chromatin clearing (p = 0.02), and intra-nuclear inclusions (p < 0.001). One case (3.2%) showed immunopositivity for SARS-CoV-2; this patient had severe disease and the lowest Ct values for tear and conjunctival samples among all positive cases.
Conjunctival smears from patients with COVID-19 revealed cytomorphological alterations, even in the absence of clinically significant ocular infection. However, viral proteins were demonstrated within epithelial cells only rarely, suggesting that although the conjunctival epithelium may serve as a portal for entry, viral replication is possibly rare or short-lived.
分析严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）在泪液/结膜上皮中的存在情况，并评估 2019 年冠状病毒病（COVID-19）患者的结膜上皮的细胞形态学变化。
在这项初步研究中，从研究所的 COVID 病房/重症监护病房招募了患有中重度 COVID-19 的患者。从 COVID-19 患者中采集泪液和结膜拭子，并送往病毒学实验室进行逆转录聚合酶链反应（RT-PCR）检测。使用结膜拭子制备涂片，对其进行细胞学评估和 SARS-CoV-2 核衣壳蛋白免疫细胞化学染色。
共纳入 42 例患者。参与者的平均年龄为 48.61 岁（范围：5-75 岁）。7 例（16.6%）患者的泪液样本中 SARS-CoV-2 核糖核酸检测呈阳性，其中 4 例（9.5%）首次 RT-PCR 检测结膜拭子阳性。在 RT-PCR 检测泪液样本阳性的患者中，涂片观察到的细胞形态学变化更为明显，包括双核/多核（p=0.01）、染色质清除（p=0.02）和核内包涵体（p<0.001）。1 例（3.2%）患者 SARS-CoV-2 免疫阳性；该患者患有严重疾病，且所有阳性病例中泪液和结膜样本的 Ct 值最低。
即使没有明显的眼部感染，COVID-19 患者的结膜涂片也显示出细胞形态学改变。然而，上皮细胞内仅很少显示病毒蛋白，表明尽管结膜上皮可能是进入的门户，但病毒复制可能很少或短暂。
