Rigid gas permeable lens binding: significance and contributing factors

A retrospective analysis of lens binding was performed using records from 279 cases of overnight wear of rigid gas permeable (RGP) lenses in a variety of materials and designs. The overall incidence of lens binding on eye opening was 22%. Typically, the lens was bound nasally, became mobile spontaneously in less than 1 h, and produced staining of the central cornea and inferior conjunctiva. A corneal indentation ring was noted in 53% of eyes that experienced a bound lens. A statistical analysis was performed to determine whether RGP lens binding was associated with particular lens parameters, patient characteristics, or lens fitting factors. Overnight lens binding was found to occur more frequently with lenses of large diameter, flat base curve and minimal axial edge lift, fitted "on-K" or flat relative to central corneal curvature, and exhibiting less than optimal on-eye lens movement before eye closure.