To explore whether cornea structure, and optical quality are affected by the covid-19 infection.

Participants with healthy corneas admitted to Tianjin Eye Hospital from November 25 to January 20, 2022 were followed up . At the end of the follow-up, the investigators recorded in detail whether the patients had undergone real-time reverse transcriptase polymerase chain reaction (covid-19 RT-PCR tests) testing, testing time and results. The presence of PCR-positive during follow-up is considered to be covid-19 infection; PCR-Negative and no symptoms of infection during the follow-up period are considered not infected; participants with symptoms but no PCR test were excluded from the study.Participants were divided into three groups according to the RT-PCR results and the presence or absence of symptoms of infection during follow-up. pentacam (Pentacam HR, Oculus, Wetzlar, Germany) was performed during follow-up and the results were recorded,and the data was statistically managed and compared.

Included Criteria

1. Best corrected visual acuity (BCVA) ≥ 20/20;
2. No other eye diseases except myopia and astigmatism;
3. The cornea was transparent, and there was no cloud or pannus;
4. No clinical manifestation of Eye disease or systemic disease;

Exclusion Criteria:

1. corneal disease;
2. ocular trauma;
3. Pregnant and lactating women;

patients admitted to refractive center of Tianjin Eye Hospital