Bandage soft contact lens barrier function: a clinical research note

Corneal thickness pre- and post-operatively was measured on 18 volunteer subjects within the context of a clinical investigation of laser refractive surgery. All measurements were taken with regard for time of day, in order to counter any complicating diurnal influence on data accuracy. Of the 18 subjects, six lost or had accidently displaced their overnight bandage soft contact lenses the first night immediately after surgery, and 12 retained theirs. The individuals with lost bandage lenses exhibited uniformly thick, swollen corneas. In contrast, the other 12 subjects, with retained lenses, exhibited a stable corneal thickness map, displaying the characteristic relatively thick periphery that transitions to a thinner central region. Moreover, in the six affected subjects, application of a new overnight bandage lens resulted in recovery of the normal thickness pattern on day 2, as opposed to the uniform swelling or oedema of the previous day. In combination, these findings indicate a fluid barrier function on behalf of the bandage soft contact lenses, which allowed the corneal endothelial pump mechanism to counteract any extreme swelling or fluid accumulation. This previously unreported phenomenon helps explain the historical effectiveness of this treatment regimen for corneal bullous, or excessive fluid-retention, conditions.