Detection of Coronavirus in Tear Samples of Hospitalized Patients With Confirmed SARS-CoV-2 From Oropharyngeal Swabs.

PURPOSE: This study was designed to detect CoV-RNA in the tears of polymerase chain reaction (PCR)-confirmed SARS-CoV-2 positive patients. METHODS: We performed a prospective case series study of hospitalized patients who have been confirmed SARS-CoV-2 positive by oropharyngeal swab within the previous 5 days. Tear samples obtained with a laboratory capillary and oropharyngeal swabs were analyzed by real-time PCR using the Altona SARS-CoV-2 Assay or the Roche SARS-CoV-2 LightMix PCR, depending on the availability. Patient history was documented, and ophthalmoscopy was used to assess for ocular surface disease. RESULTS: Of all 18 patients recruited in April 2020, 5 suffered from respiratory failure and were submitted to an intensive care unit. None of our patients had signs of viral conjunctivitis although all patients in intensive care showed chemosis and conjunctival hyperemia because of third-spacing or fluid overload. The presence of coronavirus RNA was confirmed by PCR in 5 of 18 patients (28%) in tears and 72% for oropharyngeal swabs. CONCLUSIONS: Using a tear fluid sampling technique similar to oropharyngeal lavage presents a higher percentage of SARS-CoV-2 positive tears in contrast to earlier reports that used a conjunctival swab. This does not automatically indicate viral shedding in ocular tissue or contagiousness of tear fluid.

A promising approach in laser vitrectomy executed by plasma-mediated removal of vitreous body via a diode-pumped Q-switched Nd:YAG laser.

To examine the applicability of plasma-mediated vitreous body removal, a diode-pumped Q-switched Neodymium:YAG laser was used for a possible application in eye surgery/vitrectomy. On a total of 1500 porcine vitreous bodies, removal rates were evaluated by comparing different LaserVit-tip designs (Mark I/II Gauge 19 and Mark III Gauge 22). The Nd:YAG laser, operating at a wavelength of 1064 nm and a pulse duration of 4 ns, was utilized for vitreous body removal with respective settings of 2, 3 and 4 mJ and pulse repetition rates (cut rates) from 5 to 25 Hz (300-1500 /min) in 5 Hz-steps as well as for 100 Hz (6000 cuts/min). The exposure times were selected at 10, 20, 40 and 60 s, respectively. Comparative measurements were carried out with mechanical cutters (Gauge 20 and Gauge 23), applying a fixed cut rate of 800 /min (13.33 Hz) at identical exposure times. The LaserVit-tips showed successful vitreous body removal for all laser settings and exposure times (Mark I: 6.2 g/min, Mark II: 8.2 g/min at 1500 cuts/min and 3 mJ, Mark II: 10.1 g/min, Mark III: 3.6 g/min at 6000 cuts/min at 3 mJ). Similar tip-dimensions (Gauge 22laser and Gauge 23cutter) showed comparable removal rates of 3.6 g/minlaser and 1.3 g/mincutter with settings of 6000 cuts/min at 3 mJ (laser) and 800 cuts/min for the mechanical cutter. A diode-pumped Q-switched Nd:YAG laser can successfully and gently remove vitreous body. The efficiency of the laser was comparable to that of mechanical cutters in terms of quantity of material removed per time unit.

High-Frequency Application of Cationic Agents Containing Lubricant Eye Drops Causes Cumulative Corneal Toxicity in an Ex Vivo Eye Irritation Test Model.

Purpose: High-frequency applied cetalkonium chloride (CAC) and benzalkonium chloride (BAC) 0.02% did not hamper corneal healing in a living rabbit model of induced corneal erosion. In contrast, the ex vivo eye irritation test (EVEIT) shows inhibition of healing for these substances. In a systematic ex vivo reproduction of the in vivo experiments, we discuss the background of these differences. Methods: Excised rabbit corneas (n = 5 per group) were cultured in artificial anterior chambers (EVEIT). Four erosions were induced for each cornea before starting regular 21 installations/day over 3 days of (1) CAC containing eye drops (Cationorm®), (2) 0.02% BAC. Corneal fluorescein staining, quantification of glucose-/lactate consumption, and histology were performed. Results: BAC 0.02% treated corneas showed increased epithelial lesions from 10.13 ± 0.65 mm2 to 10 ± 0.8 mm2 on day 0, to 86.82 ± 5.18 mm2 (P < 0.0001) by day 3. After a trend toward smaller lesions for CAC on day 1, erosion sizes increased significantly by day 3 from 9.82 ± 0.30 mm2 to 29.51 ± 16.87 mm2 (P < 0.05). For 1 cornea, corneal erosions nearly disappeared on day 3 (0.89 mm2). Corneal lactate increased significantly for BAC and CAC, whereas glucose concentrations were unchanged. Histology revealed disintegration of the corneal structures for both compounds. Conclusions: The data underline the EVEIT as a predictive toxicity test to show side effects in a time-compressed manner. The consistency of these predictions was previously demonstrated by the EVEIT for BAC, phosphate buffer, and others. The EVEIT is suited for a chronic application prediction of tolerability and toxic side effects of eye drops in particular, and other chemicals in general.