This is the first large-sample study on the effects of the difference between the white-to-white (WTW) and sulcus-to-sulcus (STS) diameters on vault and its related factors, and it provides clinical and practical value for the selection of implantable Collamer lens (ICL) size.

In this study, we found that there was no strong correlation between the WTW and STS diameters.

Errors can occur in choosing ICL sizes by the WTW-based prediction of the horizontal ciliary sulcus diameter, which may increase the risk of unsatisfactory intraocular lens vault and instability.

The difference between the WTW and STS diameters was large for cases with a WTW diameter or anterior chamber depth out of range; this may be associated with an undesirable vault after ICL implantation. Special attention should be paid to these patients.