Soft lens extended wear affects epithelial barrier function

Ophthalmology. 1998 Dec;105(12):2330-5. doi: 10.1016/S0161-6420(98)91237-4.


Objective: To explore the impact of eye closure and soft contact lens extended wear (SCLEW) on epithelial permeability to fluorescein (Pdc).

Design: A prospective cohort study.

Participants: Thirty-one noncontact lens (CL) wearers participated.

Intervention: The effects of eye closure on Pdc were evaluated by comparing morning (AM) and afternoon (PM) measurements on non-CL subjects. The effects of SCLEW on Pdc were determined by measuring Pdc before beginning SCLEW and then after 2, 4, and 12 weeks of SCLEW.

Main outcome measures: Pdc measured in the morning versus the afternoon and before versus after SCLEW was examined.

Results: Analyses of Pdc were done using the natural logarithm (ln). The mean +/- standard error (SE) ln(Pdc) measured in the AM versus PM on 16 non-CL wearers did not differ significantly (-2.56+/-0.16 vs. -2.69+/-0.15, respectively; P = 0.46). In contrast, the mean +/- SE ln(Pdc) in 15 subjects after 2 (-1.73+/-0.183, P < 0.001), 4 (- 1.59+/-0.188, P < 0.001), and 12 weeks (-1.99+/-0.206, P = 0.02) of SCLEW was substantially greater than that measured before lens wear (-2.42+/-0.159 ln(nm/sec)). Interestingly, the mean+/-SE ln(Pdc) measured in the afternoon on seven subjects after 13 weeks of SCLEW was similar to their average baseline ln(Pdc) (-2.62+/-0.27 vs. -2.52+/-0.243, respectively; P = 0.54). Further analysis showed that Pdc was highest in the morning and decreased approximately 12.5%/hour (P < 0.001) during the day.

Conclusions: Sleeping without CLs does not appear to alter Pdc; however, 2 weeks of SCLEW caused a 99% increase in permeability without observable changes by slit-lamp examination. Increases in Pdc appear greatest in the morning after SCLEW and then decrease exponentially during the day. Whether changes in Pdc will predict CL-associated keratopathy needs further study.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Biological Transport / physiology
  • Cohort Studies
  • Contact Lenses, Extended-Wear*
  • Epithelium, Corneal / metabolism*
  • Female
  • Fluorescein / metabolism
  • Fluorophotometry
  • Humans
  • Male
  • Permeability
  • Prospective Studies


  • Fluorescein