Personal characteristics by social isolation and loneliness.

Patients’ characteristics and details of the endoscopic procedures.

BDI-II: Beck Depression Inventory II [38]. STAI-T: trait scale of the State-Trait-Anxiety-Inventory [39]. LEC: Life Events Checklist [40]. Test for differences between groups:...

Exclusion criteria.

The association of spherical equivalent with education in separate models in the NHANES 1999–2008.

The association of myopia (≤ -0.75 D) with education in separate models in the NHANES 1999–2008.

Correlations between geographic measures and social isolation and loneliness.

Multilevel regression results for social isolation (unweighted N = 47,752).

Descriptive statistics: FSA-level measures (N = 977).

Complications during or after the endoscopic procedures.

Association analysis of corneal power and corneal astigmatism with level of education in the NHANES 1999–2008.

Multilevel regression results for loneliness (unweighted N = 47,818).

Factors related to non-recurrence in the univariate or multivariate analysis.

Clinical course after the endoscopic procedures.