Noninvasive Visualization of the Tear Film Microaerosol During Noncontact Tonometry Measurements.

PURPOSE: To investigate the aerosol generation by a noninvasive real-time observation device and assess the conditions relating to aerosolization during intraocular pressure (IOP) measurements using a commercial noncontact tonometer (NCT). STUDY DESIGN: Prospective experimental and healthy eye studies. METHODS: In an initial experimental study, we devised a model mannequin eye to investigate how air puff pressure and IOP of the eye affected aerosol generation. In the human study including 20 healthy volunteer control subjects, the number of tear aerosol particles generated at 20 and 40 mm Hg air puff pressures with and without eye drop was investigated. The recorded aerosol visualization video was analyzed and the number of aerosol particles generated in 5 seconds after IOP measurement was measured. RESULTS: The experimental and human studies confirmed the aerosol generation during NCT measurements. In the experimental study, when the air puff pressures were set at 20 and 40 mm Hg, a lower IOP (5 mm Hg) generated significantly more aerosols than a higher IOP (25 mm Hg) (20 mm Hg, P = .0159; 40 mm Hg, P = .0079). There was also a significant positive correlation between the air puff pressure and the number of aerosol particles in both high- and low-IOP eyes (P < .001). At an air puff pressure of 40 mm Hg, the amount of aerosol generated was significantly higher with eye drop than without eye drop (P = .047). CONCLUSIONS: NCT generates significant aerosolization from the tear film, the amount of which is determined by the IOP and the air puff pressure and the presence of eye drop use before the measurements.

Impact of COVID-19-Related Lockdown on Glaucoma Patients

Objectives: To analyze emergency and outpatient admissions by glaucoma patients during complete lockdown due to coronavirus disease 2019 (COVID-19) to assess the effect of pandemic-related complete lockdown on glaucoma patients. Materials and Methods: This retrospective chart review included all glaucoma patients who were either examined and/or underwent emergency surgery between March 11, 2020 and May 31, 2020, a period of complete COVID-19-related lockdown in Turkey. The data were compared with data from patients seen during the same time period in 2019. Visual acuity and intraocular pressure data from patients examined after the lifting of the lockdown were also evaluated. Results: According to Turkish Ministry of Health guidelines, only emergency examinations and surgeries could be performed during the 82 days of the COVID-19 lockdown. During this period, a total of 11 eyes of 10 patients were operated and 123 patients were examined in the outpatient clinic. During the same period in 2019, 122 surgeries were performed, 39 of which were emergencies. In the first 4 weeks after the lockdown ended, 163 patients were examined at the outpatient clinic and marked visual loss was detected in 10 eyes of 9 (5.5%) patients who did not attend follow-up visits due to the pandemic. Conclusion: During the lockdown, emergency surgeries related to glaucoma decreased by 71.7% and marked visual loss was detected in 5.5% of the patients examined after the lockdown. These findings suggest that some patients were unable to present to clinics despite needing emergency care.

Hydrodynamic Interaction Between Tear Film and Air Puff From Noncontact Tonometry.

PURPOSE: The purpose of this study was to investigate the mechanism of potential droplet formation in response to air puff deformation with two noncontact tonometers (NCTs). METHODS: Twenty healthy volunteers were examined using two NCTs, Ocular Response Analyzer and Corvis ST, and two contact tonometers, iCare and Tono-Pen. High-speed videos of the tear film response were captured with at spatial resolution of 20 microns/pixel at 2400 fps. Droplet size, droplet velocity, distance between air puff impact location, and the tear meniscus-lid margin were characterized. RESULTS: One subject was excluded due to technical issues. Droplets were detected only in tests with instilled eye drop. Videos showed the tear film rolls away from the apex while remaining adherent to the ocular surface due to the tendency of the fluid to remain attached to a solid surface explained by the Coanda effect. Twelve out of 38 videos with an eye drop administration showed droplet formation. Only one resulted in droplets with predominantly forward motion, which had the shortest distance between air puff impact location and lower meniscus. This distance on average was 5.9 ± 1.1 mm. The average droplet size was 500 ± 200 µm. CONCLUSIONS: Results indicate no droplet formation under typical clinical setting. Hence, standard clinical use of NCT tests is not expected to cause droplets. NCT testing with eye drop administration showed droplet formation at the inferior eyelid boundary, which acts as a barrier and interrupts tear flow. TRANSLATIONAL RELEVANCE: Study of tear film interaction with NCT air puff shows that these tonometers are not expected to cause droplet formation in standard use and that if external drops are required, both eyelids should be held if patients need assistance to maintain open eyes to avoid droplets with predominantly forward motion.

Audit of outcomes following attendance at the City West drive-through IOP glaucoma clinic during the COVID-19 pandemic.

BACKGROUND: Glaucoma is the leading cause of irreversible blindness globally. During the COVID-19 pandemic, an enforced reduction in capacity resulted in the deferral of routine outpatient appointments for glaucoma patients. AIM: This study analyses patient outcomes following the establishment of a drive-through intra-ocular pressure (IOP) clinic during the COVID-19 pandemic to alleviate increased pressure on the tertiary glaucoma services at Royal Victoria Eye and Ear Hospital (RVEEH) and Mater Misericordiae University Hospital (MMUH) between August 2020 and June 2021. METHODS: A 1-lane driveway system was established in a marquee on the grounds of City West hotel. IOPs were measured in patients' cars using a hand held iCare100 tonometer. Results were reviewed by a consultant ophthalmologist. At hospital follow-up clinic visits, IOP was measured using the Goldmann applanation tonometer (GAT). RESULTS: Three hundred one patients of a total of 672 who attended the drive-through clinic have subsequently attended a designated hospital follow-up appointment. In this cohort, the mean drive-through iCare IOP of 19.4 mmHg ± 6.0 was significantly higher (< 0.005) than the mean GAT IOP at the pre-drive through clinic visit (16.3 mmHg ± 3.7) and the post drive-through hospital follow-up visit (17.2 mmHg ± 4.1). Two hundred twenty-six (75%) patients did not need any treatment change, 53 (18%) required eye drop medication changes, 10 (3%) underwent a laser procedure, 4(1%) required surgical intervention, and 8 (3%) were discharged. When patient outcomes were analysed according to IOP grade assigned at the drive-through clinic, those with an iCare IOP < 21 were significantly less likely to require a treatment change. The cohort with iCare IOP ≥ 30 were significantly more likely to have a laser or surgical intervention. CONCLUSION: The implementation of a drive-through IOP clinic was a safe and effective way to monitor glaucoma patients during COVID-19, and identify those at high risk of poor IOP control or requiring a change in treatment.

How should we measure intraocular pressure in the era of coronavirus disease 2019? Balancing infectious risk, cleaning requirements, and accuracy.

PURPOSE OF REVIEW: Accurate and precise measurement of intraocular pressure (IOP) is a vitally important component of the ophthalmic examination. There are multiple methods of tonometry, each of which has considerations in light of the ongoing severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic. This review discusses these considerations and compares various tonometer methods with the gold standard of Goldmann applanation tonometry (GAT). RECENT FINDINGS: The SARS-CoV-2 virus may spread via droplets, microaerosols, or direct contact in the ophthalmology clinic. Tonometry poses a high risk of contamination. The accuracy and reliability of various methods of tonometry with single-use disposable equipment has been compared with Goldmann applanation tonometry. SUMMARY: Goldmann applanation tonometry with disposable applanation tips, Tono-pen, and iCare employ single use tips to decrease the risk of cross-contamination of infectious agents. Review of the literature demonstrates good correlation between these devices and GAT, although the published level of agreement between devices varies.

Assessment of temporal and spatial distribution patterns of aerosol produced by air-puff non-contact tonometer.

PURPOSE: To assess the distribution pattern of aerosol in the aspect of time and direction during the intraocular pressure (IOP) measurement by air-puff non-contact tonometer (NCT) and further offer references for protection from coronavirus disease-19 (COVID-19) in the routine ophthalmic examination. METHOD: A single-center observational study was conducted in the ophthalmology clinics of Peking University Third Hospital. Two air quality detectors were equipped to assess the generated particulate matter (PM) concentration simultaneously within 30 s after IOP measurement in the outpatient hall. Detector A was fixed next to the NCT as a reference, while Detector B was fixed 1 meter away. The participants were divided into two groups depending on the position of Detector B. The generation of aerosol was compared within different groups and time intervals. RESULTS: 144 participants were enrolled in the final analysis. At a 1 m distance from the NCT, the PM2.5 concentration significantly increased at the 30 s (Z = 2.898, Bonferroni-corrected P = 0.038) while the PM10 concentration increased immediately after the IOP measurement (Z = 2.967, Bonferroni-corrected P = 0.030). The PM2.5 and PM10 concentrations at 1 m were significantly higher immediately (Z = -2.183, P = 0.029; Z = -2.502, P = 0.012) and 30 s (Z = -2.021, P = 0.043; Z = -2.071, P = 0.038) after the IOP measurements when the Detector B was vertical to the air jet on the lateral side. CONCLUSIONS: NCT may produce aerosol after the IOP measurement by air-puff. The generated PM2.5 had a prolonged existence compared with PM10 at a 1 m distance. The lateral side of the air-puff direction may be of higher exposure risk to aerosol.

Teaming-up nurses with ophthalmologists to expand the reach of eye care in a middle-income country: Validation of health data acquisition by nursing staff in a telemedicine strategy.

Telemedicine can be used to conduct ophthalmological assessment of patients, facilitating patient access to specialist care. Since the teleophthalmology models require data collection support from other health professionals, the purpose of our study was to assess agreement between the nursing technician and the ophthalmologist in acquisition of health parameters that can be used for remote analysis as part of a telemedicine strategy. A cross-sectional study was conducted with 140 patients referred to an ophthalmological telediagnosis center by primary healthcare doctors. The health parameters evaluated were visual acuity (VA), objective ophthalmic measures acquired by autorefraction, keratometry, and intraocular pressure (IOP). Bland-Altman plots were used to analyze agreement between the nursing technician and the ophthalmologist. The Bland-Altman analysis showed a mean bias equal to zero for the VA measurements [95%-LoA: -0.25-0.25], 0.01 [95%-LoA: -0.86-0.88] for spherical equivalent (M), -0.08 [95%-LoA: -1.1-0.95] for keratometry (K) and -0.23 [95%-LoA: -4.4-4.00] for IOP. The measures had a high linear correlation (R [95%CI]: 0.87 [0.82-0.91]; 0.97 [0.96-0.98]; 0.96 [0.95-0.97] and 0.88 [0.84-0.91] respectively). The results observed demonstrate that remote ophthalmological data collection by adequately trained health professionals is viable. This confirms the utility and safety of these solutions for scenarios in which access to ophthalmologists is limited.

Examining the Necessity of Postoperative Day-1 Review After Pars Plana Vitrectomy: A Meta-Analysis.

BACKGROUND AND OBJECTIVES: This study aimed to evaluate the necessity of the postoperative day-1 (POD1) review after pars plana vitrectomy. PATIENTS AND METHODS: The analysis included available literature that documented medical and surgical interventions performed on POD1 review after pars plana vitrectomy. A meta-analysis of proportions was conducted using a binomial-normal model to analyze three data sets consisting of all interventions, medical interventions, and surgical interventions. Heterogeneity and publication bias analyses were performed. RESULTS: POD1 reviews of 2,262 patients across 14 studies were examined to yield a total POD1 intervention rate estimate of 4.7% (95% confidence interval [CI], 3.0-13.9). When stratified by medical or surgical intervention, the intervention rate estimates were 4.1% (95% CI, 1.4-11.6) and 0.7% (95% CI, 0.3-1.3), respectively. The most common complication requiring postoperative intervention was elevated intraocular pressure. CONCLUSION: Given the wide confidence intervals of the estimated intervention rates, variability in postoperative practices, and range of interventions performed, the POD1 review cannot be discarded in its entirety. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:513-518.].

Quantitative Evaluation of Aerosol Generation from Non-contact Tonometry and its Correlation with Tear Film Characteristics.

INTRODUCTION: Ophthalmologists are inevitably exposed to tears and ocular discharge during ophthalmologic examinations and are at high risk for SARS-CoV-2 infection. To understand the role of aerosols in disease transmission, we adopted a prospective cross-sectional study design and investigated the count and size distribution of aerosols generated by a non-contact tonometer and its correlation with individual tear film characteristics. METHODS: This study constituted two parts. The study population included outpatients who underwent an intraocular pressure examination in an intraocular pressure examination room (Part I) and 20 participants who underwent an intraocular pressure examination in a laboratory (Part II). The following main outcomes were measured: aerosol counts at 0, 50, 100, 150, and 200 cm from the non-contact tonometer (Part I); aerosol counts after each participant underwent non-contact tonometry, and lipid layer thickness score and tear film break-up time (Part II). RESULTS: The aerosol count decreased with increasing distance from the tonometer. The aerosol count at 0 cm had the highest value compared to that at other distances. For aerosols of diameters 0.25-0.5 µm and 0.5-1.0 µm, the count decreased at 50 cm and remained stable at further distances. For aerosols of diameters 1.0-2.5 µm and ≥ 2.5 µm, the count dropped progressively at all five distances. The aerosol count from each tonometer correlated positively with the lipid layer thickness score (r = 0.490, P = 0.028), whereas the aerosol count correlated negatively with the tear film break-up time (r = - 0.675, P = 0.001). CONCLUSIONS: Aerosols tended to coagulate during diffusion. A 50-cm distance from the tonometer could confer safety from aerosols with < 1.0-µm diameter. Aerosols generated during non-contact tonometry could contain a lipid layer component. Moreover, tear film stability could affect aerosol generation. Protective eyewear is recommended for reducing infection risk from aerosols. Individual tear film characteristics should be considered during non-contact tonometry.

Case Report: Steroid-induced Ocular Hypertension in a 6-year-old Boy.

SIGNIFICANCE: Systemic corticosteroid use in children is rare because of known risks of adverse effects. The increased prevalence of multisystem inflammatory syndrome associated with COVID-19 may change this. It is critical for eye care providers to be aware of potential severe and rapid ocular hypertensive response to prevent irreversible vision loss. PURPOSE: The purpose of this study was to report the importance of early monitoring of intraocular eye pressure in pediatric patients on systemic steroid medication. CASE REPORT: A 6-year-old White boy presented with a complaint of headache for 2 weeks. He was on his 19th day of treatment for acute lymphoblastic leukemia with oral dexamethasone and chemotherapy. IOP at presentation was 65 mmHg in both eyes measured with iCare tonometry. Treatment with maximum topical glaucoma therapy reduced IOP to normal levels and eliminated the symptom of headache. CONCLUSIONS: This case reminds eye care providers to be aware of the potential ocular hypertensive response to systemic steroid treatment and the importance of establishing early monitoring. With the emergence of multisystem inflammatory syndrome in children during the current COVID-19 pandemic, eye care providers may encounter more pediatric patients on systemic corticosteroid treatment than previously and should adjust their examinations appropriately.

COVID-19-related Ocular Hypertension Secondary to Anterior Uveitis as Part of a Multisystemic Inflammatory Syndrome.

It is the consensus of the medical community that ocular complications associated with Coronavirus Disease 2019 (COVID-19) are mild, self-limiting, and there are no reports to date of a sight-threatening event. We report a patient with a systemic inflammatory syndrome in the context of COVID-19, with ophthalmological (uveitis), dermatological (erythema and skin nodules), and cardiovascular (edema) manifestations. The anterior uveitis led to an increase in the intraocular pressure that failed to respond to clinical treatment and prompted a surgical intervention to save the vision. To the best of our knowledge, this is the first report of a COVID-19-related ocular hypertension. Timely surgical intervention was key to save the vision in the patient's only eye.

[Examination of patients with glaucoma during the COVID-19 pandemic]. / Metody obsledovaniya bol'nykh glaukomoi v period pandemii COVID-19.

PURPOSE: To evaluate the efficacy of the optimal examination technique for patients with glaucoma during the COVID-19 pandemic that includes one of the safest methods of tonometry [transpalpebral tonometry (TPT), contour dynamic tonometry (CDT) and Icare rebound tonometry (RBT)] in combination with spectral domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA). MATERIAL AND METHODS: The study included 65 patients with primary open-angle glaucoma (POAG) who sought medical aid at the Ophthalmological Center of FMBA during the COVID-19 pandemic; they were examined using three tonometry methods: RBT, TPT and CDT. All patients underwent central corneal thickness measurement, perimetry, OCT and OCTA with assessment of vessel density (VD) of the superficial plexus in the macula (whole image macula) and peripapillary retina (PPR). RESULTS: High correlation was found between the results obtained with RBT, TPT and CDT. None of the methods showed a correlation between IOP and corneal thickness. The correlations between IOP and OCTA parameters were obtained: IOPTPT and VDPPR in the inferior temporal sector (r= -0.386, p=0.027), IOPRBT and VD whole image macula (r= -0.69, p=0.019), and in the macula inferior hemisphere (r= -0.75, p=0.008), as well as between the ocular pulse amplitude (OPA) and VD in the macular inferior hemisphere (r=0.380, p=0.039). The OCTA parameters had a moderate, but significant correlation with the perimetric indices. CONCLUSIONS: Tonometry methods (TPB, CDT and RBT) exhibit high correlation with each other and no correlation with corneal thickness. IOP parameters measured by different methods, especially using the Icare tonometer, correlate with OCTA parameters, and the latter - with perimetric indices. The combination of these tonometry methods with SD-OCT and OCTA is optimal for examining patients during the pandemic.

Home Monitoring for Glaucoma: Current Applications and Future Directions.

Technological advances provide a number of options for glaucoma monitoring outside the office setting, including home-based tonometry and perimetry. This has the potential to revolutionize management of this chronic disease, improve access to care, and enhance patient engagement. Here, we provide an overview of existing technologies for home-based glaucoma monitoring. We also discuss areas for future research and the potential applications of these technologies to telemedicine, which has been brought to the forefront during the ongoing COVID-19 pandemic.

Intraocular Pressure Telemetry for Managing Glaucoma during the COVID-19 Pandemic.

PURPOSE: To evaluate in glaucoma patients the feasibility and use of remote monitoring of intraocular pressure (IOP) with an implanted telemetry sensor during the coronavirus disease 2019 (COVID-19) lockdown. DESIGN: Cross-sectional study. PARTICIPANTS: Patients previously implanted with a telemetric IOP sensor (Eyemate; Implandata GmbH) were included. METHODS: Intraocular pressure measurements acquired by the patients during the lockdown were collected by physicians who were located remotely. A questionnaire was sent to 10 participating study centers to evaluate the clinical impact of remote monitoring of IOP via the IOP sensor system. MAIN OUTCOME MEASURES: Number of patients who obtained home IOP measurements. RESULTS: Data were available from all centers and from 37 eyes of 37 patients (16 patients with a sulcus-based sensor and 21 patients with a suprachoroidal sensor). Thirty-four patients obtained IOP measurements during the lockdown. Mean age of the patients was 69.3 ± 9.6 years, and 48.6% were women. A total of 8415 IOP measurements from 370 measurement days were obtained. Based on remote IOP measurements, treatment was changed in 5 patients. In another 5 patients, treatment change was considered when physicians received the IOP measurements after the lockdown. Nine of the 10 study centers judged remote IOP measurements to have a clinical impact. CONCLUSIONS: These results show the feasibility of patient-acquired measurement of IOP in conjunction with remote IOP monitoring by physicians with an implantable sensor. The data obtained impacted clinical decision making, including adjustment of ocular hypotensive therapy and avoiding unnecessary office visits during the COVID-19 pandemic.

Effect of Intraocular Pressure on Aerosol Density Generated by Noncontact Tonometer Measurement.

PRECIS: Aerosols generated by a noncontact tonometer (NCT) were quantified. There was a positive correlation between aerosols and intraocular pressure (IOP), and the concentration of aerosols beside the air jet port was the highest. PURPOSE: To investigate the effects of IOP on the aerosol density generated during the use of an NCT and provide references and suggestions for daily protection of ophthalmic medical staff during the coronavirus disease-19 (COVID-19) outbreak. OBJECTIVE AND METHODS: This cross-sectional clinical trial included 214 eyes of 140 patients from a hospital in Wenzhou city, Zhejiang Province. All subjects' IOPs were measured by an NCT (39 eyes with low IOP, 90 eyes with normal IOP, 37 eyes with moderately high IOP, and 48 eyes with very high IOP) between March 7 and June 17, 2020. The density of particulate matter (PM) 2.5 and PM10 generated during the process of IOP measurement with an NCT was analyzed. IOP values were recorded simultaneously. The aerosols generated during different IOP measurements were plotted in scatter plots. RESULTS: PM2.5 was generated more at the air jet port of the tonometer during the process of IOP measurement (H=2.731, P=0.019). Larger quantities of PM2.5 and PM10 were generated when the IOP was higher, and these differences were statistically significant (PM2.5: H=119.476, P<0.001; PM10: H=160.801, P<0.001). Linear correlation analysis with one variable demonstrated that IOP had significantly positive correlations with PM2.5 (r=0.756, P<0.001) and PM10 (r=0.864, P<0.001). CONCLUSIONS: Aerosols can be generated while using an NCT to measure IOP, and aerosols and IOP are positively correlated. Patients with moderately high IOP or very high IOP tend to generate more aerosols during the IOP measurement. The concentration of aerosols beside the air jet port was the highest.

Drive-through Intraocular Pressure Checks During the COVID-19 Pandemic.

PRECIS: A drive-through clinic was created to obtain intraocular pressure measurements before a virtual visit with their provider, in order to provide care for patients in the Kellogg Glaucoma Clinic while minimizing risk of COVID-19 transmission. PURPOSE: The aim of this study was to establish a drive-through clinic model to provide glaucoma care for patients while minimizing the risk of COVID-19 transmission. PATIENTS AND METHODS: A drive-through clinic was created by adapting a 1-lane, 1-way driveway adjacent to the Kellogg Eye Center building entrance. Patients were physicianselected from the Glaucoma Clinic at Kellogg Eye Center as existing patients who required intraocular pressure (IOP) checks and therapeutic management and were chosen based on their ability to be managed with an IOP measurement primarily. The entrance was otherwise closed to the public, allowing staff to utilize an adjacent vestibule with glass walls and sliding doors as a staffroom. Patients were instructed to arrive within a 15-minute time window at which time they would drive through the lane and stop their cars under an awning over the driveway. Ophthalmic technicians wearing appropriate personal protective equipment then approached each car, confirmed patient information, and measured IOP. Once the data were recorded using a mobile workstation, the physician was able to complete each visit by discussing the findings and therapeutic plan with the patient, either in-person in real time or virtually by phone or video visit at a later time. RESULTS: A total of 241 visits were completed over 14 half day clinic sessions, with number of drive-through visits ranging from 5 to 45 per session. CONCLUSIONS: It is possible to institute a drive-through model of IOP checks for glaucoma patients which is efficient and minimizes the risk of exposure to COVID-19 for patients and staff.

Mask-induced Artifact Impacts Intraocular Pressure Measurement Using Goldmann Applanation Tonometry.

PURPOSE: The coronavirus (COVID-19) pandemic has impacted ophthalmology practices significantly. American Academy of Ophthalmology and Center for Disease Control guidelines suggest mandatory masking of patients and physicians during outpatient visits. We have recently become aware of a mask-induced phenomenon, whereby the intraocular pressure (IOP) as measured by Goldmann applanation tonometry (GAT) is artificially elevated due to mechanical interference from the mask. CLINICAL PRESENTATION: A 37-year-old male with a history of primary open-angle glaucoma on triple therapy presented for a routine visit. CLINICAL FINDINGS: When measuring IOP by GAT the right eye measured 16 mm Hg, but the left eye measured 20 mm Hg. The patient's mask was noted to be touching the base of the sensor rod on the tonometer. This patient's IOP was falsely elevated due to the lateral edge of his mask touching the base of the applanation tonometer, changing the relationship between the bi-prism tip and the weighted balance below, and eliminating the weighted balance from the pressure measuring mechanism. The patient's mask was adjusted to ensure there was no touch and repeat measurement showed an IOP of 16 mm Hg in the left eye. CONCLUSION: Recognizing mask-induced alteration in IOP is essential as it could lead to unnecessary escalation of treatment. We recommend flattening the area of mask protrusion during applanation and ensuring that the sensor arm remains clear of the mask while the tonometer tip approaches the cornea, especially at the moment the mires become visible during corneal contact.

Increased microbial loading in aerosols produced by non-contact air-puff tonometer and relative suggestions for the prevention of coronavirus disease 2019 (COVID-19).

OBJECTIVE: To evaluate the microbial loading in aerosols produced after air-puff by non-contact tonometer (NCT) as well as the effect of alcohol disinfection on the inhibition of microbes and thus to provide suggestions for the prevention and control of COVID-19 in ophthalmic departments of hospitals or clinics during the great pandemics. METHODS: A cross-sectional study was carried out in this study. A NIDEK NCT was used for intraocular pressure (IOP) measurement for patients who visited Department of Ophthalmology in Qilu Hospital of Shandong University during March 18-25 2020. After ultra-violate (UV) light disinfection, the room air was sampled for 5 minutes. Before and after alcohol disinfection, the air samples and nozzle surface samples were respectively collected by plate exposure method and sterile moist cotton swab technique after predetermined times of NCT air-puff. Microbial colony counts were calculated after incubation for 48 hours. Finally, mass spectrometry was performed for the accurate identification of microbial species. RESULTS: Increased microbial colonies were detected from air samples close to NCT nozzle after air-puff compared with air samples at a distance of 1 meter from the nozzle (p = 0.001). Interestingly, none microbes were detected on the surface of NCT nozzle. Importantly, after 75% alcohol disinfection less microbes were detected in the air beside the nozzle (p = 0.003). Microbial species identification showed more than ten strains of microbes, all of which were non-pathogenic. CONCLUSION: Aerosols containing microbes were produced by NCT air-puff in the ophthalmic consultation room, which may be a possible virus transmission route in the department of ophthalmology during the COVID-19 pandemic. Alcohol disinfection for the nozzle and the surrounding air was efficient at decreasing the microbes contained in the aerosols and theoretically this prevention measure could also inhibit the virus. This will give guidance for the prevention of virus transmission and protection of hospital staff and patients.