Objective:To analyze the proportion of patients with acute primary angle-closure glaucoma (PACG) after the outbreak of coronavirus disease 2019 (COVID-19) in patients undergoing glaucoma surgery and the factors influencing morbidity.Methods:A cross-sectional study was performed.The cluster sampling method was used to collect 141 glaucoma patients hospitalized for glaucoma surgery after the outbreak of COVID-19 in Xuzhou First People's Hospital from December 16, 2022, to January 16, 2023, and 231 glaucoma patients hospitalized for surgery in the same 1-month period from 2019 to 2020, 2020 to 2021, 2021 to 2022 through the hospital information system.Ninety-two eyes of 92 patients with acute PACG after the outbreak were selected as a study group, and 21 eyes of 21 patients with acute PACG hospitalized during the same 1-month period from 2021 to 2022 were selected as a control group.The proportion of patients with different types of glaucoma during the observation period was analyzed.The proportion of patients with acute PACG and the clinical characteristics of acute PACG were analyzed, including age, sex, visual acuity, intraocular pressure (IOP), and anterior chamber angle status.Epidemiological data such as the use of anti-cold medications, and changes in living habits and moods (including daily water intake and anxiety) of patients after COVID-19 infection were obtained by telephone follow-up.Anxiety levels of patients in the study group were assessed using the Hospital Depression and Anxiety Scale (HADS).The triggering factors of acute PACG attack after the COVID-19 outbreak were analyzed.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Xuzhou First People's Hospital (No.xyyll[2023]114).Written informed consent was obtained from each subject.Results:The proportion of acute PACG patients in Xuzhou First People's Hospital within one month after the outbreak in 2022 to 2023 increased significantly compared with the same period in 2021 to 2022, 2020 to 2021 and 2019 to 2020, and the differences were statistically significant ( χ2=31.066, 33.331, 20.804; all at P<0.001).There was no statistical significance in the distribution of the number of eyes with different grades of visual acuity, IOP, the number of eyes with IOP ≥30 mmHg (1 mmHg=0.133 kPa), and the distribution of the number of eyes with different anterior chamber angles between the two groups (all at P>0.05).Patients in the control group had no history of COVID-19 infection or use of cold medicines at disease onset.During disease onset, all 92 (100%) patients in the study group had positive COVID-19 nucleic acid test results, of which 57 (61.96%) patients had a history of oral anti-cold medication use.During the same period, 49 (100%) hospitalized patients with other types of glaucoma had positive COVID-19 nucleic acid test results, of which 20 (40.82%) patients had a history of oral cold medication.There was a statistically significant difference in the proportion of patients taking oral cold drugs between acute PACG and other types of glaucoma in the study group ( χ2=5.764, P=0.016).During the outbreak of COVID-19, the study group reported that the daily water intake had increased to varying degrees than before.In the study group, 76 patients had anxiety, accounting for 82.6%.Multiple linear regression analysis showed that IOP=19.052+ 0.009×daily water intake+ 0.858×HADS score ( R2=0.780), and the standardized coefficients of daily water intake and HADS score were 0.542 and 0.452, respectively.Daily water intake had a greater effect on IOP than HADS score. Conclusions:The proportion of acute PACG patients among hospitalized surgical glaucoma patients increased significantly after the COVID-19 outbreak, which is related to risk factors such as oral anti-cold medications containing vasoconstrictors or antihistamines, increased daily water intake, anxiety and other lifestyle, and mood changes.