Published online Sep 26, 2022. doi: 10.12998/wjcc.v10.i27.9619
Peer-review started: December 17, 2021
First decision: January 26, 2022
Revised: January 27, 2022
Accepted: August 21, 2022
Article in press: August 21, 2022
Published online: September 26, 2022
There have been increased reports of dry eyes in the coronavirus disease 2019 (COVID-19) pandemic era.
To analyze the differences in tear film properties from pre- and post-pandemic of the COVID-19 era.
It was a retrospective comparative study. Patients were divided into three groups according to the data of multimodal ocular surface evaluation: (1) Group 1 if it was before Portugal lockdown decision (from August 2019 to March 2020); (2) Group 2 if it was after Portugal lockdown decision but without mask mandate (from April 2020 to October 2020); and (3) Group 3 if it was after Portugal lockdown but with mask mandate in health public highway (from November 2020 to April 2021). The following variables were analyzed: Lipid layer thickness, blink rate, Schirmer test, tear meniscus height, tear osmolarity, non-invasive break-up time, and loss area of the meibomian glands.
The study included 548 eyes of 274 patients, aged 18 years to 89 years, with a mean age of 66.15 ± 13.40 years at the time of multimodal ocular surface evaluation. Compared to group 1: (1) Mean lipid layer thickness was better in group 2 (P = 0.001) and group 3 (P < 0.001); (2) Schirmer test was similar in group 2 (P = 0.576) and better in group 3 (P = 0.002); (3) Tear osmolarity and loss area of the meibomian glands were worse in group 2 (P = 0.031 and P < 0.001, respectively) and in group 3 (both with P < 0.001); (4) Blink rate and tear meniscus height were similar in group 2 (P = 0.821 and P = 0.370, respectively) and worse in group 3 (P < 0.001 and P = 0.038, respectively); and (5) Non-invasive break-up time was worse in group 2 (P = 0.030) and similar in group 3 (P = 0.263).
Our study demonstrated that differences existed in tear film properties comparing data from the pre- and post-pandemic of the COVID-19 era.
Core Tip: There were differences in tear film properties comparing the pre- and post-pandemic of the coronavirus disease 2019 era data. Over time, there was an increase in the lipid layer thickness, a decrease in the area of the meibomian glands, and a decrease in the blink rate. These changes seemed related to face masks and screen time. Therefore, the ophthalmologist must be aware of these changes and educate patients according to the most likely potential causal factor.