Impact of COVID-19 pandemic on the ocular surface

Figure 3 Loss area of meibomian gland, tear meniscus height, lipid layer thickness, and non-invasive break-up time grade frequencies between August 2019 and April 2021. Between April 2020 and June 2020, no evaluation was performed due to the lockdown. Loss area of meibomian gland grade: Abnormal (> 60), borderline (40-60), and normal (< 40). Tear meniscus height grade: Abnormal (< 0.22), borderline (> 0.44) and normal (0.22-0.44). Lipid grade: Sbnormal (< 60), borderline (60-80), and normal (> 80). Non-invasive break-up time grade: Abnormal (< 5), borderline (5-10), and normal (> 10). MG: Meibomian gland; NIBUT: Non-invasive break-up time.