By using 16S rRNA sequencing technology to analyze the changes in ocular surface microbiota before and after surgery, as well as the impact of changes in ocular surface microbiota on FS-LASIK induced DES, new treatment ideas are provided for corneal FS-LASIK induced DES patients, and the incidence of FS-LASIK related DES is reduced.

This study aims to include 160 postoperative patients, who will be divided into a dry eye group and a normal group based on postoperative dry eye examination. Microbial samples of the patient's conjunctival sac will be collected, and changes in the ocular surface microbiota before and after surgery will be analyzed using 16S rRNA sequencing technology. The impact of changes in the ocular surface microbiota on FS-LASIK induced DES will also be analyzed, providing new treatment ideas for FS-LASIK induced DES patients and reducing the incidence of FS-LASIK related DES.

Inclusion Criteria:

1. Age ≥ 18 years old;
2. Stable refractive index (refractive index change less than 0.5D in the past 2 years);
3. The best corrected far vision (CDVA) is 1.0 or better;
4. Postoperative dry eye patients need to meet the following criteria: Patient's Eye Surface Disease Index (OSDI) ≥ 13 and two of the following three criteria are met: Tear film rupture time (BUT) ≤ 10S Schirmer I test (mm/5min) ≤ 10mm, corneal fluorescein sodium staining exceeding 5 spots;

Exclusion Criteria:

1. History of eye trauma or surgery;
2. Suspected keratoconus;
3. Previously suffering from other eye diseases such as keratitis or edema, glaucoma, uveitis, retinal detachment, macular degeneration, cataracts, amblyopia, etc.;
4. Preoperative history of severe dry eye disease;
5. Patients with systemic diseases, such as hyperthyroidism or autoimmune diseases; Or severe mental disorders, such as anxiety and depression;

Dry eye patients after FS-LASIK